Siglent SPD3303D review - Page 1
Forum section: electronics / testgear

author: FrankBuss
author_rank: Unknown
timestamp: September 07, 2013, 11:25:12 pm
content: My short review of the SPD3303D:The test in the video starts with a serious problem on channel 3, with the fixed voltages output: there are big voltage spikes (up to 7V), even with load, if you turn it on or off. And it overshoots, if you short the output. UPDATE: seeherehow to fix these problems.But there were no problems on channel 1 and channel 2 and it can be even used for a hand drill.I opened the case at the end of the video, but it is not a full teardown and very short, because I don't know much about analog electronics anyway.Not shown in the video:one hour load test with 8 ohm on channel 1 and channel 2 each, and 2 ohm on channel 3. The fan starts, not too loud, and the power supply survived itif you want to use the PC software, you have to instal the NI environment first:http://joule.ni.com/nidu/cds/view/p/id/4230/lang/en(the registration doesn't need eMail confirmation, so enter what you want)I've tested the channel 3 a bit more, and on the 5V selection there is a voltage of 82mV when turned off, 48 mV for 3.3V and 46 mV for the 2.5V selection. Can be loaded with 2 ohms, still there.problem with "all on/off": if e.g. channel 1 is on, channel 2 and 3 are off, and then I press "all on/off", it turns all channels on. I would expect that it turns any channel off, which is on, but maybe it is just me who is surprised by this featurelock-key: in lock-mode, it is still possible to change the voltage from the PCparallel and series mode: in parallel mode, channel 1 and channel 2 are parallel (and available at the terminals at channel 1), for currents up to 6.4A, and in series mode channel 1 and channel 2 are linked in series (and available at the negative terminal of channel 1 and the positive terminal at channel 2), for voltages up to 64V. Unfortunately it is just a relay internally, the display doesn't sum the voltage or the current and it is the same, as if you would link it externally (which is possible, too, because the channels are all independent of each other)wave display: this shows a waveform of the voltage and current. Can be enabled individually for each channel. It is difficult to read, because there are no scale lines and it has no auto-scaling.As said in the video, my conclusion: the power supply is not perfect, but it is nice for the price and I would buy it again.Discussion about my power resistors and some more ideas for cheap homebrew dummy loads:https://www.eevblog.com/forum/testgear/power-resistor-dummy-load-for-psu-testing/The stackable cables with banana plugs are from this eBay shop:http://stores.ebay.de/chrI'm not affiliated with this seller, but I have bought such cables from other sellers and they were very bad, with thin wires with an iron/copper alloy and not very solid plugs. So maybe this is useful, if someone wants to buy good cables.High resolution photos:logic board, left sidelogic board, right side, far focuslogic board, right side, near focusmains switchregulator board, left side (there is some rust)regulator board, right sidetop view, backtop view, fronttop view, lefttop view, rightThe mosfets on the heatsinks are IRFP150N. There are two of them on the right heatsink, but only one on the left heatsink, and looks like a temperature sensor is mounted instead on one heatsink. And there is another big 4 leg IC on each heatsink, which has no label (doesn't look like it was sanded, just mounted the wrong way on the heatsink). On the logic board the main microcontroller is a STM32F103. There are some PC817 photocouplers and some JQC-3FF relays.

author: Hydrawerk
author_rank: Super Contributor
timestamp: September 08, 2013, 12:57:13 am
content: It's like... I do not need any color LCD, give me a simple PSU with no spikes and no other HW problems. I have heard good things aboutStatronPSU.http://www.statron.de/details/19http://www.statron.de/details/306I love the 1980's style. But yes, these PSUs are manufactured today.

author: FrankBuss
author_rank: Unknown
timestamp: September 08, 2013, 06:22:21 am
content: I've used a Statron at a client, good quality, I like the multi-turn potentiometer for the voltage. But you can't control it from a PC, which is useful for some applications, if you write your own programs to control and monitor it.For example once I helped working on a watchdog problem, where once in a while a device reseted right at boot. To see if the problem was fixed, a complicated setup was built, with an external relay to switch a power supply. Would be just a few lines of code with a power supply with USB, and you can detect a successful booting by reading the current consumption with one of the USB commands, or by combining the code with which controls the power supply with some readings from the serial port of the DUT.

author: Zbig
author_rank: Frequent Contributor
timestamp: September 08, 2013, 10:32:15 am
content: Quote from: FrankBuss on September 07, 2013, 11:25:12 pmIt's not exactly just a relay. The channels are actually being put in tracking mode by software so their control loop controls are tied together (with "slave" following the "master"). It wouldn't work that way if the firmware wasn't "aware" of the serial/parallel mode you're currently in. It's only the actual summing of readings what it doesn't do for you.

author: george graves
author_rank: Super Contributor
timestamp: September 08, 2013, 10:45:39 am
content: This (I hope) isn't a silly question ..... but how hard can it be to design a PS WITHOUT a turn on spike?!?!?!?

author: Zbig
author_rank: Frequent Contributor
timestamp: September 08, 2013, 11:29:27 am
content: I'd just like to add few things about my SPD3303S which I like more in comparison to Rigol DP832 (not having one, based on what I read and saw here): *)I like the red/green LED indicators of CC/CV operation directly above the relevant channel. It seems intuitive to me and it is what I'm used to after my (brief) encounters with other/older supplies.It seems all the electrolytics are Rubycons.I like the mains power switch better. The Rigol rocker type one seems "cheap" to me and not really appropriate for the purpose.It's much shorter and I like the simple "blocky" design.After inspecting stills from Frank's brief "case open" presentation (thank you and can we have some HQ photos, pretty please?) it seems there are at least two pass transistors per each of the main channels which is a good thing thermal-wise and less prone to some borderline thermal dissipation issues, I guess?After FrankBuss posted some more details it seems I was wrong on that one.All channels are isolated. I must admit I haven't checked that but I assume the manual doesn't lie about it.What I like less but think I can live with (again, comparing to Rigol DP832):No numeric keypad of any kind - you have to dial the parameters in using the encoder.Third channel being fixed 2.5V/3.3V/5V only. Not really that big of a deal for me as I mostly work with digital so I can almost always power the logic with one of those.No voltage or current reading for third channel whatsoever. I think this could be a deal breaker for some and almost makes you think the third channel was a kind of an afterthought. But personally I imagine inspecting my new circuit carefully using one of the main metered outputs and not caring about the readings that much afterwards after I already know what to expect.I can imagine situations where hard current limit (in contrast to CC mode) would come handy but sadly, you won't find it here.*) Disclaimer:I have no intention of proving anything to anyone (including myself). It's just because Rigol 832 is kind of a hot topic here as of recently and just maybe my post will help someone with his/hers buying decision.

author: FrankBuss
author_rank: Unknown
timestamp: September 08, 2013, 12:27:19 pm
content: I just checked the isolation of the three channels: first I measured it with an ohm meter, then wiring channels 1&2 in series, 1&3 in series and 2&3 in series. For all tests I loaded it with 8 ohm. Looks like it worked, the voltage was as expected.

author: Hydrawerk
author_rank: Super Contributor
timestamp: September 08, 2013, 01:26:26 pm
content: Yes, the Statron looks like it was developed in mid 1980s.

author: FrankBuss
author_rank: Unknown
timestamp: September 08, 2013, 02:01:58 pm
content: The warranty seal is broken anyway, so I've updated my first posting with some photos.

author: Zbig
author_rank: Frequent Contributor
timestamp: September 08, 2013, 02:03:59 pm
content: Quote from: FrankBuss on September 08, 2013, 02:01:58 pmCool! Thank you, FrankBuss.

author: Zbig
author_rank: Frequent Contributor
timestamp: September 08, 2013, 02:35:13 pm
content: Quote from: FrankBuss on September 07, 2013, 11:25:12 pmI think that would be the rectifier bridge.

author: FrankBuss
author_rank: Unknown
timestamp: September 10, 2013, 01:13:20 pm
content: I've done some scope plots for the problem on channel 3 and sent it to the support. It doesn't need to be a problem of the PSU in general, maybe my unit is just broken, but I doubt it. Maybe someone can verify it with his/her unit, if you have the same PSU?I loaded channel 3 with an 8 ohm resistor, then I turned the PSU on with the power-switch (the PSU was turned off a few hours before). As you can see, there is a 1.5V spike, falling down over some milliseconds (1V and 1ms per division). The voltage selection for channel 3 was on 5V. If I turn it off for just a minute, and then on again, the spike can be even higher, I've measured up to 7V. There should be no voltage at all, because the channel is turned off initially when I turn on the PSU.Same setup, this is what I see when I turn it off with the power-switch, and channel 3 still not enabled. A big 5V spike, falling over 100ms. And this is at 0,6A, because of the 8 ohm load. A sensitive DUT could be destroyed by it.Same setup, channel 3 loaded with 8 ohm, the channel output was turned on with the CH3-ON/OFF switch, and then I shorted the output. As you can see, there are some serious overshoots, up to 12V! If I have a sensitive DUT attached and accidentally short the power supply outputs momentary, it could be destroyed by such overshooting. I don't trust this output at all anymore, because maybe there are some other overshoots, depending on the dynamic behavior of the DUT.Just for comparing this with the other channels and to verify my measurements: same setup, but this time for channel 2 (8 ohm load, turned on). I shorted it momentary, as with the test for channel 3. As you can see, nice regulation without overshooting. Same for channel 1, no problems.

author: Zbig
author_rank: Frequent Contributor
timestamp: September 10, 2013, 02:05:12 pm
content: Quote from: FrankBuss on September 10, 2013, 01:13:20 pmAs I have already reported in some SPD3303 threads before, I too have a voltage spike on CH3. I have SPD3303S HW ver. 1.0. It goes up to 12V on mine. I haven't tested the overload recovery overshoot. I can post some oscillograms later.

author: FrankBuss
author_rank: Unknown
timestamp: September 10, 2013, 02:13:59 pm
content: Quote from: Zbig on September 10, 2013, 02:05:12 pmThanks, so my unit is not broken. I hope they know a fix, or we have to reverse engineering the circuit and try to fix it ourselves

author: Hydrawerk
author_rank: Super Contributor
timestamp: September 10, 2013, 02:25:03 pm
content: I miss a numeric keyboard on this Siglent PSU. Even some old PSUs have it.

author: Zbig
author_rank: Frequent Contributor
timestamp: September 10, 2013, 02:25:18 pm
content: Quote from: FrankBuss on September 10, 2013, 02:13:59 pmYeah, would be great if they come with a fix for this. But when it comes to messing around with it by myslef, I think I'd just rather learn to disconnect my DUT physically first before turning the power off and vice versa. Now, that recovery overshoot could be another story, I wasn't aware of that...

author: Zbig
author_rank: Frequent Contributor
timestamp: September 10, 2013, 02:30:45 pm
content: Quote from: Hydrawerk on September 10, 2013, 02:25:03 pmWell, the one on your photo doesn't have any knob so it better havesomeway of selecting the voltage ;-) I too wouldn't mind additional numeric keypad but it's not a deal breaker for me in any way. I imagine this could even be safer sometimes as it's much easier to accidentaly punch in 29V instead of 2.9V than to accidentally crank it up all the way up with a knob.

author: Zbig
author_rank: Frequent Contributor
timestamp: September 10, 2013, 06:12:10 pm
content: As promised, I attach my results (SPD3303S, HW1.0)

author: FrankBuss
author_rank: Unknown
timestamp: September 10, 2013, 06:32:23 pm
content: Looks very similar to my oscillograms, and I can confirm your examples with no load, the impulses are longer. This is a confirmation that it is a design bug. Or a series production error, some wrong components.

author: djeans
author_rank: Contributor
timestamp: September 22, 2013, 08:18:17 pm
content: abo !Frank, Thanks for the review. Exactly what I was looking for.As I saw, you bought this PSU on ebay.I am fighting with myself since more the 3 weeks to not buy ... still fightingRegading the spikes: would a big capacitor help, something like 4700µ or so ?EDIT: forgot to ask: is this thing hackable? I mean that you get an S model with a simple hack? I can not imagine that they have build something different.

author: FrankBuss
author_rank: Unknown
timestamp: September 22, 2013, 08:51:40 pm
content: Quote from: djeans on September 22, 2013, 08:18:17 pmI don't know. But meanwhile the support sent me a description how to fix it, with soldering and replacing some new parts inside (all standard parts which you can get at Digikey or Farnell). There were some inconsistencies between the parts I can see on the image they sent, and what they described in the repair text what I should use, but as soon as this is resolved, I'll try it and then publish the results here, and the description of the fix, if Siglent don't mind (they sent me a nice board screenshot from their CAD program with top/bottom side traces and annotations how to fix it).Quote from: djeans on September 22, 2013, 08:18:17 pmMaybe, but why do you need a higher resolution than 10mV/10mA? There are no separate sense inputs, so depending on the length of the cables and the current, the voltage at your breadboard might be off by several millivolts anyway, because there are no external sense inputs, and I don't know an application where I would need to set the current limit with higher resolution.

author: djeans
author_rank: Contributor
timestamp: September 23, 2013, 06:37:23 pm
content: Quote from: FrankBuss on September 22, 2013, 08:51:40 pmnice, would be interessed in what they do. If you are allowed, maybe you can post it here.Quote from: FrankBuss on September 22, 2013, 08:51:40 pm10mV is in fact sufficient, but because it's fun and it does not hurt to have the ability to change in 1mV ;-) I also assume that there is a kind of linux there.. then you can add for example ethernet interface etc.

author: Zbig
author_rank: Frequent Contributor
timestamp: September 23, 2013, 07:59:38 pm
content: Quote from: FrankBuss on September 22, 2013, 08:51:40 pmThat's great news. Looking forward for your update on that matter.

author: Zbig
author_rank: Frequent Contributor
timestamp: September 23, 2013, 08:04:06 pm
content: Quote from: djeans on September 22, 2013, 08:18:17 pmYou'd ruin the CC mode response this way.Quote from: djeans on September 22, 2013, 08:18:17 pmWhy would you assume that? It doesn't seem that's the case to me. It's not like they're slapping Linux on each and every device equipped with large graphical LCD, you know...

author: FrankBuss
author_rank: Unknown
timestamp: September 23, 2013, 08:17:16 pm
content: I want to avoid unscrewing the front panel (I think I can solder all parts for the channel 3 fix without unscrewing, will get some missing parts tomorrow), but it looks like the only microcontroller in the system is the STM32F103, which would be too small for Linux.

author: FrankBuss
author_rank: Unknown
timestamp: September 29, 2013, 01:51:49 am
content: Just a short update: I've discussed the remaining problems with the very helpful Siglent support and after the fix the power on/off spikes are completely gone and the short circuit problem is solved for me, too.5V short circuit test after the repair:2.5V short circuit test after the repair:I'll publish the repair instructions with the CAD screenshots as soon as I get the permission from Siglent.

author: Hydrawerk
author_rank: Super Contributor
timestamp: September 29, 2013, 04:20:29 pm
content: Well, always buy a product that is in production for one year or so. Never buy a very new equipment with hardware bugs.

author: FrankBuss
author_rank: Unknown
timestamp: September 30, 2013, 09:05:44 am
content: Siglent permitted to publish their CAD screenshots, this is what they sent me:The instructions:a: add a transistor, model 2N3904(Thru-hole) or MMB3904(SMD), connected as the circuit showsb: add a 1000pF capacitor, connected between pin 2 and pin 3 of JC1c: change the ZD703 to the 3.3V zener diode 1N4728Ad: replace CC13 with a 100nF capacitor, in series with a 20k resistorStep d was a bit complicated, but I managed it by soldering both parts upright at one side of each pad, and then connecting the top sides with a wire. The old CC13 was 100nF, too, so could be used for this step, if it survives the desoldering. I used a new one, just to be sure. 0805 works fine, but looks like the original parts are 0603, but I had already all passive parts in 0805. This is how it looks like:Instead of soldering at JC1, which seems to be soldered to the board, I measured it with an ohm meter and looks like pin 2 of JC1 is connected to junction of the big 0.04 ohm current measure resistor at the bottom and the diode DC5, and to pin 1 of UC5 (the middle pin, bad numbering in the CAD diagram), which made it easier to repair, because I could solder the transistor and the new capacitor at the bottom and use just a wire for the other side of the new capacitor.This didn't really fix the overshooting, but after some more communication with the support, I got another instruction: Change RC5 to 200 ohm:I used 220 ohm, and now it looks (nearly) perfect:Just to show the effect of the changes, before the repair:and after the repair:And the power-on/power-off spike is gone, too.for Siglent, now I can recommend this power supply without reservations. The support told me that these changes are already included in a new revision of the PSU, maybe ask them which version you get if you don't want to open it and fix it yourself

author: Zbig
author_rank: Frequent Contributor
timestamp: October 03, 2013, 09:43:42 pm
content: I've fixed mine according to this description and I can confirm that CH3 problems are gone now. Great job, Frank!

author: FrankBuss
author_rank: Unknown
timestamp: October 03, 2013, 10:06:15 pm
content: Looks neat with the heat shrink tubing and hot glue.

author: Zbig
author_rank: Frequent Contributor
timestamp: October 12, 2013, 10:33:27 pm
content: I've just found a rather hilarious firmware bug. The developers apparently cut some corners and it looks like when you save a preset (you can store up to 5 of them) it actually just dumps the RAM image to non-volatile storage. The result is, when you restore a preset, the start-up counter gets restored as wellI guess it's supposed to be an equivalent of a car's odometer so don't rely on it to much if you're planning on getting a second hand SPD3303Mine's firmware version is 1.01.01.01.03R1 (now, that's a mouthful).

author: FrankBuss
author_rank: Unknown
timestamp: October 13, 2013, 05:02:40 am
content: Same in my version (I have firmware 1.01.01.01.05), it shows the start-up counter saved in the preset after restart.But not very useful anyway. In a lab it could be started just 10 times, but running 24x7 for years, and a hobbyist could start it 200 times, but only for half an hour each time.

author: Zbig
author_rank: Frequent Contributor
timestamp: October 13, 2013, 11:08:56 am
content: Quote from: FrankBuss on October 13, 2013, 05:02:40 amExaclty, and it doesn't tell you what it's been through (powering an Arduino for whole its life or some heavy inductive loads?), either. I don't care much about it, just find it kind of funny

author: FrankBuss
author_rank: Unknown
timestamp: October 16, 2013, 04:08:27 pm
content: Wold be interesting to take a look at the firmware, if you want to ask for a 1.01.01.01.05 firmware update file

author: Zbig
author_rank: Frequent Contributor
timestamp: October 16, 2013, 05:55:17 pm
content: Quote from: FrankBuss on October 16, 2013, 04:08:27 pmYou mean ask Siglent support? Sure, why not, but I don't know their e-mail (never contacted them yet). Could you provide it, please?

author: FrankBuss
author_rank: Unknown
timestamp: October 16, 2013, 06:35:15 pm
content: There is a "Customer Service" navigation on their webpagehttp://www.siglent.com/en, but looks like they screwed it up, at least in Firefox and Opera it is not click-able. Last time I just wrote to sales@siglent.com (the only eMail address I could find on their webpage) with the request to forward it to technical support.

author: psycho0815
author_rank: Regular Contributor
timestamp: October 17, 2013, 02:33:40 pm
content: it's clickable on chrome, but there's only links for msn-messenger and skype in the menu, no email. There is however an emailform on siglent.eu when you click on "contact us" right at the bottom of the page.Personally i'd propably take the rigol over this one, but that's more of a gut thing than anything else.Also, never heard anything bad about batronix (including own experiences), which is kind of a big point for me.

author: Zbig
author_rank: Frequent Contributor
timestamp: October 17, 2013, 02:47:53 pm
content: My gut feeling was more towards Siglent and I'm very glad I made that decision. Have you seen the massive thread dedicated to problems with Rigol? Well, my Siglent had only some issues with CH3 which are now fixed. Comparing to the Rigol, Siglent has:Each of the three channels properly isolated from each otherNo power-on/off spikes of any kind on the main CH1 and CH2 from the get goParallel and serial modes do actually make the connections internally with relays hence no need for a shorting bar (yes, it matters to me)Anyway, are you sure that's really the gut feeling? Or is it because Siglent's PSU didn't get Dave's attention?EDIT:Oh, after reading some updates on the Rigol thread and how they "solved" the overheat issue: the fan on my Siglent is idling under no load conditions, I can barely hear it.

author: psycho0815
author_rank: Regular Contributor
timestamp: October 17, 2013, 03:29:17 pm
content: Nah, believe it or not, but dave's not a factor here.The overheating issue with the rigol seems to be fixed. I don't think anyone has actually tested yet, whether or not the overshoot issue is still an present in the newest rev.As for the siglent fix. I don't want to solder in some bodge myself. I want the manufacturer to fix it. So if i can find a retailer, who can guarantee to deliver the newest rev. without the issues than maybe.Also:I really don't like the fact that i can't set a current limit on the 5V channel. I know i can use ch1 or 2 at 5V but still. Just doesn't seem thought through.Also i want a number pad. I like knobs as well as the next guy, but i like being able to just punch in a value, too. It's digital anyway so there's really no excuse. Especially for stuff like the timer it would be alot more convenient. Sure the keypadlayout on the rigol is ridiculous, but at least it has one.All that said, a 3 channel psu is more of a want than a need for me anyway so maybe i just wait a couple months and revisit the market than to see if the newest revs. ironed out all the kinks on either unit.

author: Zbig
author_rank: Frequent Contributor
timestamp: October 17, 2013, 03:35:34 pm
content: Fair enough, the "auxiliary" nature of the CH3 and lack of the numerical keypad, while not being the issues for me personally, are perfectly valid points.

author: jimjam
author_rank: Regular Contributor
timestamp: June 02, 2014, 04:54:46 pm
content: Quote from: psycho0815 on October 17, 2013, 03:29:17 pmSo psycho, which power supply did you end up getting? And what do you think of it?

author: ScottyAU
author_rank: Contributor
timestamp: June 23, 2014, 09:42:15 am
content: Is there a revision of this guy now from siglent with the hardware changes mentioned in this thread included?Cheers.

author: FrankBuss
author_rank: Unknown
timestamp: June 23, 2014, 12:22:28 pm
content: Quote from: ScottyAU on June 23, 2014, 09:42:15 amI don't know, maybe ask here again:https://www.eevblog.com/forum/testgear/siglent-technical-support-join-in-eevblog/

author: jimjam
author_rank: Regular Contributor
timestamp: June 23, 2014, 12:45:52 pm
content: So to recap, before I ask the Siglent guy, the issues were:- Spikes / overshoots on CH3 during power on / power off- Spikes when the output of CH3 is shortedHave I missed anything else?

author: FrankBuss
author_rank: Unknown
timestamp: June 23, 2014, 01:03:02 pm
content: Right, these were the problems. And a minor usability problem: when setting the voltage, you can either adjust it in 1 V steps, or with the "fine" button in 0.01 V steps, but not in 0.1 V steps. Maybe they have a new firmware which fixes this (my firmware version: 1.01.01.01.05, hardware version: V1.1), I made some suggestions like pressing the fine button longer for 0.01 V and short for 0.1 V steps, because at least for my applications usually I need 0.1 V steps.

author: jimjam
author_rank: Regular Contributor
timestamp: June 23, 2014, 01:06:48 pm
content: Instead of pressing the button longer, perhaps it could be just a normal press to change the "cursor" position. Each time it's pressed, it would cycle through 1V, 0.1 and 0.01 (and 0.001 for the 3303S model)

author: FrankBuss
author_rank: Unknown
timestamp: June 23, 2014, 01:18:56 pm
content: Right, cycling would be even better, because the same concept for both models. The current step size could be displayed on the graphics display.

author: jimjam
author_rank: Regular Contributor
timestamp: June 23, 2014, 01:28:52 pm
content: Quote from: psycho0815 on October 17, 2013, 03:29:17 pmI just noticed this. Does CH3 have any short circuit protection?

author: FrankBuss
author_rank: Unknown
timestamp: June 23, 2014, 02:02:45 pm
content: Yes, ch3 is limited to 3 A max. and short circuits are no problem.

author: ScottyAU
author_rank: Contributor
timestamp: June 24, 2014, 06:14:15 am
content: I've just ordered one from a local supplier here in Australia who says there stock is only a few weeks old.Will post back when it arrives.

author: jimjam
author_rank: Regular Contributor
timestamp: June 24, 2014, 06:22:08 am
content: What and where did you get it from?

author: ScottyAU
author_rank: Contributor
timestamp: June 24, 2014, 06:24:52 am
content: Post in other Thread

author: ScottyAU
author_rank: Contributor
timestamp: June 24, 2014, 06:36:31 am
content: Triotest heard back from Siglent - they said they fixed the issue in December.Triotest assure me the current stock will include this fix!Scotty

author: TRIO Test and Measurement
author_rank: Contributor
timestamp: June 24, 2014, 07:04:24 am
content: Hi folks, as Australia's sole Siglent authorised distributor, I'd like to set some minds at ease. We have received quite a few emails asking if our stock of SPD3303D is the latest version and has this voltage-transient bug fixed. Siglent has confirmed in writing to us that it is fixed in all our current stock.We have stock as of today of all three of the PSU's in this family. Links are here and includes the new SPD3303C for those that don't need the graphical display on the "D" model.http://www.triotest.com.au/shop/en/search?controller=search&orderby=position&orderway=desc&search_query=siglent+spd&submit_search=SearchCheck-out the new SPD3303C. It is great value.http://www.triotest.com.au/shop/en/dc-bench-supplies/3448-siglent-spd3303c-195w-dc-power-supply-30v-3a-x-2-25v33v5v3a-x-1-10mv-step.htmlAlso, if anyone wants a bargain oscilloscope, we are clearing-out the standard screen size 150MHz SDS1152CM for just $395.00 (+gst for Aussies). These are new with full a Siglent 3 year warranty supported in ANZ by us.http://www.triotest.com.au/shop/en/siglent/2952-siglent-digital-storage-oscilloscope-150-mhz-bandwith-2-channel.htmlCheers!

author: ScottyAU
author_rank: Contributor
timestamp: June 24, 2014, 07:06:32 am
content: Really appreciate the reply TRIO Test - thanks very much!

author: Siglent
author_rank: Regular Contributor
timestamp: June 24, 2014, 08:30:26 am
content: As early as last year, we have fixed this problem, please rest assured purchase.

author: FrankBuss
author_rank: Unknown
timestamp: June 24, 2014, 09:36:08 am
content: Quote from: Siglent on June 24, 2014, 08:30:26 amThanks. In which hardware version was it fixed, if someone wants to verify it? When I click on the version button on my device, it shows "hardware version V1.1".

author: Siglent
author_rank: Regular Contributor
timestamp: June 24, 2014, 09:57:26 am
content: the hardware is still V1.1, but we have corrected the mother board version. the Prior version is SDY8.007.038D, now it has been modified to SDY8.007.038E ( as the figure showed)

author: ScottyAU
author_rank: Contributor
timestamp: June 26, 2014, 11:32:13 am
content: My Siglent arrived today. Bit hesitant to open it up just yet to check the boardDisplay says Software 1.01.01.01.06 Hardware V1.1I've hooked it up to the scope and done a few tests (screens below). All tests done on the 3rd connector set to 5v with a load resistor across the 3rd output.1) Cold power on2) Shorting the 3rd connector3) Removing the short on the 3rd connectorBe interested in peoples thoughts...

author: jimjam
author_rank: Regular Contributor
timestamp: June 26, 2014, 11:43:24 am
content: Is that a 1V - 1.5V spike on power on?

author: ScottyAU
author_rank: Contributor
timestamp: June 26, 2014, 11:47:31 am
content: Unless i'm doing it wrong (which is entirely possible) - yep!

author: jimjam
author_rank: Regular Contributor
timestamp: June 26, 2014, 11:55:50 am
content: Quote from: ScottyAU on June 26, 2014, 11:47:31 amSo much for that....I guess it's still better than Rigol DP832:https://www.eevblog.com/forum/testgear/found-bug-in-rigols-dp832/msg348106/#msg348106

author: ScottyAU
author_rank: Contributor
timestamp: June 26, 2014, 12:20:02 pm
content: That's only on a cold boot - turning the whole supply on.The channel on/off does't spike.Shorting the output does a little.Frank i'd be interested in your thoughts mate if you read this - or Siglent.

author: FrankBuss
author_rank: Unknown
timestamp: June 26, 2014, 12:34:27 pm
content: The 1 V overshoot after the short is more than twice as much as I measured, as you can see here:https://www.eevblog.com/forum/testgear/siglent-spd3303d-review/msg299246/#msg299246Still better than without the fix, which had 7 V overshoots (so up to 12 V), so I guess you have a new version. I wouldn't care about it, it is below absolute maximum limits of nearly all attached 5 V electronics, like old TTL ICs, or an Arduino.Can you compare it with ch1 and ch2? If there are no overshoots, you can be sure that it is not your measurement setup, like ground loop, impedance mismatch (but this is unlikely with 1 ms per division), to long cables etc.But it is strange that you have some voltage on cold power on, I don't see this on my patched device.

author: nowlan
author_rank: Frequent Contributor
timestamp: June 26, 2014, 12:34:57 pm
content: would 1-1.5v kill anything though?

author: ScottyAU
author_rank: Contributor
timestamp: June 26, 2014, 12:50:39 pm
content: Thanks for the feedback Frank.I can confirm there is no overshoot on channel 1 or 2 (just tested).I'm happy

author: FrankBuss
author_rank: Unknown
timestamp: June 26, 2014, 01:07:14 pm
content: Quote from: nowlan on June 26, 2014, 12:34:57 pmFor example the datasheet of the ATmega128A says 6 V absolute maximum rating for operating voltage, but the chip doesn't know the datasheetand I'm sure it doesn't matter much if there is a short milliseconds long overshoot to 6.5 V. Once for a PIC I swapped Vcc/GND on a breadboard, wondering why it got really hot, and the chip survived it. A random datasheet for a 74LS00 says 7 V for supply voltage as its absolute maximum rating.But I would suggest to connect your sensitive circuits only to one of the current limited channels anyway, and use channel 3 just for more robust things, like a fan.

author: ducatistou
author_rank: Newbie
timestamp: August 15, 2014, 01:42:51 pm
content: Hi,Happy to join you for my first post on EEVBLOG, my favourite electronics blog and Youtube chanel.I'm a french electronics and radio listener amateur, so excuse my approximative english !I have an issue with my new PSU Siglent SPD3303D. Since i have installed the PSU in my radio shack, i have some RF perturbations in my RTL2838 SDR Radio with SDR-Radio V2.2 consoleIt's a brand new SPD3303D with last firmware and hardware I suppose because I don't have overshoot at turn on or <1 VThe PSU is well grounded, the RTL dongle is very far from the PSU (more than 10 meters) in an other room, but the PSU is not so far from the antenna with a HF LNA, 4 m high, and 15m of low loss cable to the RTL dongleWhen the PSU is on and output chanels off, everything is okWhen I turn on a chanel I have a cyclic perturbation and when I turn on the 2 chanels I can hear the same perturbation at half frequency than the previous one. These interferences appear on single, serial or parallel modeYou can see the waterfall screenshots and the audio files herehttp://1drv.ms/1t2OKzLI'll try to contact the support supplyThe output signal on scope is not so bad with very few interferences in digital modeThank you if you have any suggestionsBREric

author: FrankBuss
author_rank: Unknown
timestamp: August 15, 2014, 02:18:01 pm
content: That's interesting, because it is a linear power supply and not a switched-mode. Maybe it is some noice from the CPU board? I can't see the frequencies, but looks very regular, like the harmonics of the CPU clock.Do you see these interferences with cables on the DC output connected or with no cables, too? If it is with cables, maybe you can fix it by adding some ferrite beads to the output, which might need some PCB scratching and soldering. If it is without cables, it might need some serious rework, like shielding the logic board, or maybe it injects noise in the mains input, because of insufficient filtering.

author: ducatistou
author_rank: Newbie
timestamp: August 15, 2014, 06:19:02 pm
content: Thank you for your replySiglent EU support has sent my request to their engineers, fast support answer ! Wait now for engineers answerI can see interferences with or without cables on DC output, may be a little bit stronger with cables.Here is an exemple with SDRSharp near 120 Mhz where I guess the interferences strongerI plugged the PSU on a Shaffner main filter with no difference, but it is a more a common than a differential RF filterI also think it comes from the CPU board, but why only when an output is onPS : this is an exemple without LNA, direct antenna (external discon) on RTL dongle

author: ducatistou
author_rank: Newbie
timestamp: August 15, 2014, 07:40:50 pm
content: I made an other test :I put the Siglent PSU near and very close to the RTL dongle and computer and surprisingly i noticed no interferences ! The dongle is shielded in a little PCB boxI put back the PSU in the shack far from tuner and interferences went back thru antenna and/or coax i supposeUnfortunatly ... i use the PSU in the shack not in the radio room, then i can't power the LNA with the Siglent !!

author: FrankBuss
author_rank: Unknown
timestamp: August 15, 2014, 08:05:33 pm
content: Looks like it is related to how near it is to the antenna. But is there a reason why you are using a EUR 300 lab power supply to power a LNA? There are much cheaper linear power supplies without any microcontroller.

author: ducatistou
author_rank: Newbie
timestamp: August 15, 2014, 08:34:53 pm
content: thank goodness, it's not for the LNA ! But as it is on for my electronics projects and hacks it could do so ... but not. One of my old free homemade power does obviously better ...and i have to switch it off when i'm listening SDR. I like this PSU for what it can do, design and accuracy, but as you say for $300 i didn't expect such annoying issue in HF domain, hope it will not interfere in my next radio projects

author: ducatistou
author_rank: Newbie
timestamp: August 18, 2014, 06:59:02 am
content: Here is the Siglent's engineer answer :"Hi Eric,I don’t know much about the RF perturbations, So I cannot understand it well.One explanation is because there is a feedback circuit which produces crosstalk while you opened the output channels.If you have any doubt, please feedback."

author: artelse
author_rank: Regular Contributor
timestamp: November 07, 2014, 10:55:52 pm
content: Hi,Have been on the lookout for a new PSU and this Siglent catched my eye. What I am wondering about, is there a real benefit to have an LCD screen on the device instead of just a nice LED panel like on the SPD3301C version?Thanks!

author: FrankBuss
author_rank: Unknown
timestamp: November 08, 2014, 03:24:00 pm
content: Looks like the SPD3303C is very similar. Some modes are missing, like the wave display or the timer, but if you just need a normal power supply, the LED panel should work, too. But the contrast and brightness of the display of the SPD3303D is very good, so it is a matter of taste, if you prefer good old LED digits.

author: g0hjq
author_rank: Unknown
timestamp: November 09, 2014, 04:58:27 pm
content: Thanks for the review Frank,I've just received my SDP3303D, which cost a 240 GB Pounds from Barsoom.eu on Amazon. Surprisingly it was sent by DHL direct from China, and arrived in 5 days.From what I've seen so far, it looks like a nice power supply - reasonably compact, easy to use, 3 isolated outputs, very quiet, and the problems with glitches on Channel 3 seem to have been fixed.NewFile1.png shows channel 3 (top) and 1 (bottom) at power on from cold with no load. Output 3 spikes at up to 1.7 volts, then drops down to about one volt. I can't imagine this causing problems with the 3.3 or 5v logic loads it's obviously intended for.NewFile2.png shows channels 3 (top) and 1 (bottom) when the outputs are switch on.NewFile3.png shows channel 3 recovering from a short circuit. Removing a 2 amp load causes just a few tens of milivolts ripple before setting down.The LCD display is gorgeous - very clear and easy to read, but I'm not really sure it's worth the extra cost over the SPD3303C with the LED display.Gary.

author: artelse
author_rank: Regular Contributor
timestamp: November 12, 2014, 09:44:45 pm
content: Thanks for the response! I am still undecided about getting the Rigol DP832 or the Siglent SPD3303D.. The good thing about the Siglent is the small footprint while the Rigol is quite a beast, but has more options.

author: FrankBuss
author_rank: Unknown
timestamp: November 13, 2014, 04:22:25 am
content: The Siglent is cheaper than the Rigol. If the Siglent has all features you need, then it might be better for you.But I think the user interface of the Rigol is better, sometimes you just want to enter the voltage, not turning a knob endlessly (the SPD3303D has no acceleration function, at least not in my firmware version, but might be not a good idea for voltage adjustments anyway). An advantage for some applications is that all three channels of the SPD3303D are isolated. The DP832 has just two fully isolated channels, the GND of channel 3 is shared with GND of channel 2. But on the SPD3303D there is no display for the current for channel 3, just a LED for overload.

author: Siglent
author_rank: Regular Contributor
timestamp: November 13, 2014, 07:30:22 am
content: Quote from: g0hjq on November 09, 2014, 04:58:27 pmDear Gary,thank you very much for the review, SPD3303D is better than SPD3303C. not only for the screen, but also for the programming function. more information here.http://siglent.blog.com/2013/05/16/use-siglent-programmable-dc-power-supply-to-complete-a-variety-of-test-solutions/

author: willd1971
author_rank: Regular Contributor
timestamp: November 21, 2014, 08:48:13 am
content: If anyone's interested I have a couple of SPD3303C units in stock at Labtronix in the UK at £190ea. They are new stock so don't expect the CH3 problems described above. Here's the link:http://labtronix.co.uk/drupal/shop/powersupply/spd3303C

author: Murray
author_rank: Newbie
timestamp: November 21, 2014, 03:34:58 pm
content: Does anyone know what the output capacitance of this supply is?The Rigol DP832 has 1000uf directly across the output, which seems to me like it could defeat the usefulness of the current limit in some cases. The Korad programmable thing has 330uf. I was wondering what this one had.Thanks

author: FrankBuss
author_rank: Unknown
timestamp: November 22, 2014, 03:30:28 am
content: Quote from: Murray on November 21, 2014, 03:34:58 pmThat's an interesting question. I measured it:Test setup: Channel 1 on, current limit set to 10 mA with "fine" adjustment, voltage to 1 V. Then I connected a scope to a 10 ohm resistor and then the resistor leads to the power supply output while it was on. As you can see, it needs 2.3 ms to discharge to 37%, so with t=RC <=> C=t/R I think the output capacitor is 230 uF.But the interesting part is the 4.7 ms delay before we can see the current limitation. So I tested it with 100 ohm and 5 V output voltage:For 40 ms twice the selected output current is not good.This made me wonder what happens if you turn on the channel with load, when it should go to CC mode immediatly. New test setup: 10 ohm and scope connected to the channel 1 output, channel 1 is turned off, current limit set to 10 mA. Then I turn on channel 1:As you can see, it starts with 2 V, which means for the first millisecond there is a current of 200 mA instead of 10 mA. And after 10 ms the output voltage drops down to nearly 0 V, then rising again to the expected 0.1 V for the CC mode. Same problem for 100 mA current limit, it starts with 200 mA. But I guess no problem for most circuits, even a low current fast fuse would not blow in a millisecond.But it is worse with 1 ohm (screwed to the power supply output terminals) and 100 mA current limit, output voltage set to 10 V:Within the first few microseconds there is a peak of 3.2 A, the maximum output of the power supply, 32 times the selected limit. Again, it is too short to harm most DUTs, so I can live with that, but looks like there is room for improvement for Siglent how to implement the current limitation.

author: rf-loop
author_rank: Super Contributor
timestamp: January 26, 2015, 07:11:45 am
content: Quote from: Murray on November 21, 2014, 03:34:58 pmOutput capacitors are 220uF (+/- tolerances)Here also tiny test with SPD3303S for test it for load step response. Here Load change from 0.375A to 0.75AStep change in load using FET switcher (Switch FET is there IRF540N) unit controlled By Siglent SDG805 pulses and dummy load resistor set. (2kHz 170us pulses higher load) Switcth unit setup so that load rise and fall time roughly around 3-4us. (some amount softened switch so that dummy load resistors and wiring reactances do not produce ringing and disturb test.). CH4 is connected to switch D and S.Compared with equal test setup (including wiring) with Agilent 6632B what is 1x 0-20V 5A well known very good linear PSU.Agilent regulation set forFASTmode using switch in Agilent PSU rear panel. (as can see it is quite fast). Both was set for 7.5V and 3A limit so it means that both run full time in CV mode of course.Agilent have also sense lines. Connected just for "self happy" with jumpers between output terminal. Not sensed over real loa wires. But oscilloscope is connected to terminals, not after wiring to load. (same also with Siglent, measurement direectly from output binding posts and separate line to load.Of course Siglent loose this game but it was very clear before I get result. But Siglent result is not at all bad. It is also good to note that this Agilent list price strating from US$ 2,800)Images are self explanating.deleted (wrong information due to problem in this test demo unit.)I'm doing more many kind of tests but due to lack of time for this, I do these later.EDIT: This test totally obsolete. After tests it more I have found that this SPD3303S have problem.After then control board is changed as warranty issue. This case have delayed due to my own lack of time for this case.Later new tests.

author: rf-loop
author_rank: Super Contributor
timestamp: January 27, 2015, 02:22:31 pm
content: In meant time before more tests.SPD3303SMains voltage 230Ac6 hour:CH1 and CH2 total out 195W.Independent mode, both channels running in CV (constant voltage) to dummy load.~31.22V and current ~3.122A)Room temp 22 celsius.No any signs of any kind of temperature problems.Also measured exhausted air temp. 41 - 42 celsius.3 hour:CH1 and CH2Independent mode.Both channels adjusted for 32V and 3.2A.Output terminals short circuited.Room temp 22-23 celsius.After 3 hour not any kind of signs about any kind of temperature problems.Exhausted air temp 40 - 41 celsius.

author: Sang
author_rank: Newbie
timestamp: March 13, 2015, 11:32:33 am
content: My CH3 is a bit high,CH1 (set to 12V) outputs 12,000 according to my Fluke 87VCH2 (set to 12V) outputs 11,999but CH3 outputs either 2,523 3,325 or 5,022 voltthat is out of spec isn't it?Both with or without a load

author: rf-loop
author_rank: Super Contributor
timestamp: March 13, 2015, 12:37:16 pm
content: Quote from: Sang on March 13, 2015, 11:32:33 amIt is well inside specifications. (even if there is decimal point error and 8% is 0.8% is it is just inside specs and it is good it is small amount up due to fact it do not have sense lines for compensate V drop due to wire resistances. (also small drop in internal wires from regulator to output terminals))Just for example: 3A load, wires to load 1m lenght (2 wires). Wire: 1mm2 copper. Loop resistance 0.034 ohm. Voltage total drop in these wires ~102mV !CH3 specifications:

author: Sang
author_rank: Newbie
timestamp: March 13, 2015, 07:48:43 pm
content: Good point, Thank you.I could not find that in the paper manual it came with.

author: rf-loop
author_rank: Super Contributor
timestamp: May 06, 2015, 05:16:48 am
content: My some old tests was "garbage" due to problem on the SPD3303S control board. Also there was small problem in IRF540 based power switch unit used in test.My "demo" SPD3303S is repaired and it have now new control board. (long delay to repair it in my workshop was just my own reason, not Siglent. (just lack of time for working with this, and because this is my demo unit what is not used for lab work and failure was not "fatal class")In all next tests HW version is 1.2. (also on PCB, printed version new) And FW version 1.01.01.06R2.First 2 images.Both power supplies with same settings. 20V and current limit 3ALoad. Continuous 1A and load step to 2A, step duration 300us. Oscilloscope CH1 show switch control signal from Siglent SDG5082 to switch unit what control PSU load. Load is set of selectable power resistors)Switching period is 2ms. 1A 1.7ms and 0.3ms 2A. It need note that switch turn on and off edges are quite fast (enough for this purpose)(just note oscilloscope scale. 100mV/div and Voltage is 20VDC (oscilloscope input AC coupled)Result is good.This is Agilent 6632B 20V 5V very good quality linear system power supply.Next image. Short circuit.(not "copper rod short" but short using power switch unit (it use IRF540 as switch.)CH1 is switch control signal from Siglent SDG5082SPD3303S settings: 20V and 3A.Next three images: SPD3303S.Channel output tur ON with different voltages for look if there is any voltage where is gives some peak. (it is good to know that there is 4 internal primary voltage levels before output regulation stages. It is nessessary for reduce power dissipation with different voltages and load currents. So it steps to desired transsformer tap with different output voltages.No any noticeable or worrying voltage peaks during the run-up ramp. Just smooth turn on.Next. Voltage set for 32V and current limit 3.0AConnected different loads ("0" ohm, 0.5 ohm to 10 ohm) to output using switch module.Also there is trace with output off and output continuously on. (just for ref)This show how it switch from CV mode to CC mode and recover to CV.Next two images:Recovery from 1ms output short with different current limits. (CV --> Shorted (CC) --> recover back to CV)1. 0.6A to 3.0A with 32V2. 0.1A to 1A with 32V and 16VThen next CH1 and 2 Series connected mode (full 64V)From off to ONNext four images about CH3.Short circuit recovery, No LoadShort Circuit recovery, 10 ohm Load (@5V 0.5A)CH3 turn ON with 10 ohm loadCH3 turn ON with NO load. (exept scope probe)

author: Zbig
author_rank: Frequent Contributor
timestamp: May 06, 2015, 09:19:42 am
content: The images don't show.I'm sorry, they do. Just some corporate proxy issues. Thank you for the analysis.

author: Marblefish
author_rank: Newbie
timestamp: June 08, 2015, 07:11:53 pm
content: Hi,My first post - just discovering electronics as a hobby after a break of a few decades. I am in the process of selecting a bench power supply as an upgrade to my current ‘ hobbled together supply’ as a birthday present to myself. After reading the excellent review by Frank, I wondered if when setting the unit up to provide a positive & negative supply (20v) is it best to use the Siglent in Independent mode & link Ch1- to Ch2+ together and use the ground as 0v rail or in Series mode with ground as 0v? I was thinking that in Independent mode you only have to adjust one channel & the 2nd channel follows accordingly.Many thanks.

author: Zbig
author_rank: Frequent Contributor
timestamp: June 09, 2015, 10:06:17 am
content: It's the other way round: you only have to adjust the voltage on one channel while in Series mode. In Independent mode, the channels are... well, independentI'd personally use Series mode in this scenario as it saves you from using a shorting bar and ensures both channels are sharing the load equally (and your 0V indeed sits in the middle). Also, trying to keep both channels' voltages in sync manually could turn to be a bit tedious (same knob shared by two channels).

author: monz
author_rank: Contributor
timestamp: June 10, 2015, 11:58:26 pm
content: This is correct, in series mode it automatically connects + on channel 1 to - on channel 2 (becomes the common connection) and the voltage and current adjustment track each other. I was disappointed to find that in series mode the channel 2 current is not measured. The current reading on channel 1 is simply duplicated to channel 2. So if I have a load between common and channel 1 - it displays current (and shows the same reading for channel 2, which has nothing connected) and if I connect a load from common to channel 2 + it displays no current. I don't know if this is a software bug or hardware limitation. I would think the relay inside just connects the two channels together just as if this was done externally with a jumper. Or maybe they incorrectly assumed in the software a load would only be across both with com never connected.This and the bug where it saves the power on count when presets are saved make me wonder about the quality of the firmware.Other than that annoyance, it has been very good, there have been no issues and the output voltage is very accurate. It's also not as deep as many and takes up less room on the shelf.

author: FrankBuss
author_rank: Unknown
timestamp: June 11, 2015, 10:50:46 am
content: I think it is a feature, because the series mode is intended for a higher output voltage, so it makes sense to show the same current.

author: monz
author_rank: Contributor
timestamp: June 12, 2015, 02:12:52 am
content: This would make sense when connecting across both supplies in series for situations where higher voltages are needed since the current would be the same, it should then show double the voltage and only display the total.But since a common connection is provided (labeled com along the gray line showing the series output connections below binding posts), this can't be assumed since there would be different loads between the negative side and ground and the positive side and ground as shown in the photos.It seems like an incorrect assumption is being made in the software. Maybe I'm wrong, just doesn't seem right. I would think pressing the series button simply puts the two in series via a relay, the same as connecting them internally, then sets the software so the control tracks.neg---- com ---- pos, couldn't resist using the meter thing!

author: leonerd
author_rank: Regular Contributor
timestamp: October 23, 2015, 12:56:14 am
content: Just to add my thoughts on this unit:Hardware-wise it's nice. A good shape, size, the buttons are useable, and so on.However, software-wise the UI is quite a let-down. Given the size of the TFT screen, Siglent haven't made good use of it at all. It's little more than four large numbers and some status indications - a TFT-shaped translation of the actual LED digit displays on the 3303C.When you're using the dial to adjust the setting of voltage/current, there's no onscreen indication that the numbers you're adjusting are the settings, and not live readout. After a short timeout, it goes back to live readout, with no display of the setting. To say again more clearly: While setting, you cannot see the live readouts. While displaying live readouts, you cannot see the set values.The coarse/fine button makes it very inconvenient to enter such voltages as 5.50V. You have to dial to 5.00V in coarse, then in 0.01V increments all the way up from .00V to .50V - that's fifty clicks of the wheel. There are some "cursor left/right" buttons just below the wheel that could be used to move the adjustment position between 10V, 1V, 0.1V and 0.01V.The operation of the "All on/off" button is less than ideal. When fewer than all three channels are turned on (which is fairly likely), pressing this button turns them all on. That feels rather unsafe to me - I would hope that if any channel is on, the button works as "All off". Only when all are off, does pressing it turn them all on. And even then I would want a confirmation, or maybe force me to long-press it to turn them all on. In its present mode of operation I don't think I'd ever be brave enough to touch it.Speaking of "all three channels" - I know it's only really a two channel PSU with a cut-down 5V third, but there is no indication on the screen as to the status of the third channel. I don't know if the hardware itself has the capability to measure the live current being sourced by Ch3, or even know what voltage it is set to, but given as the button LED and the "All on/off" button respond to the status of Ch3, I suspect the management CPU is at least aware whether Ch3 is on or not. Could that be displayed on the screen too?This is supposed to be fairly simply bench PSU - you should be able to set voltage and current levels, see live measurements of them, and turn on and off channels. And yet the UI on the screen fails to be useful at any of these basic operations.All of these are software issues on the embedded - and upgradeable - firmware. All of these could be fixed. I see that Siglent themselves are a contributor on this forum; indeed on this very thread.Siglent - I would love to see some improvements in this UI. For that matter, I'd love to help you make some improvements. All the hardware is there on this device, it just needs some nicer software to round it off into a really great PSU. I could throw a few mockups of display screens into this (or maybe a different) thread, see what people think to the ideas. I don't want to just complain for the sake of complaining; I'd like to help make it better. Maybe between us we can all work on improving the user experience with this device.

author: tautech
author_rank: Super Contributor
timestamp: October 23, 2015, 08:00:29 am
content: Welcome to the forumleonerd.One has to ask what FW version is installed?

author: leonerd
author_rank: Regular Contributor
timestamp: October 23, 2015, 09:11:58 am
content: Quote from: tautech on October 23, 2015, 08:00:29 amI did once manage to make it tell me:Code:SCPI> *IDN?< Siglent Technologies,SPD3303,SPD30CE4xxxxxx,1.01.01.01.06R1,V1.2I do have an r2 image file, but lacking any change or release notes I can't tell if reflashing it would make a difference here. I don't haveeasyaccess to a Windows machine to run the Windows software to update it, so any reflash operation is going to involve either moving the heavy PSU, moving an even-heavier computer, or finding a Linux program that can do it.

author: FrankBuss
author_rank: Unknown
timestamp: October 23, 2015, 11:44:20 am
content: Unfortunately last time I tried to update it, it didn't work, I got the messages "Failed to search device". Where can I download the latest firmware version and firmware update program? And what was changed?Would be really nice to set the voltage in 0.1 V steps. Usually I need to set 3.3 V, 5 V etc., and almost never 0.01 V steps and then it is annyoing and time consuming to setup the voltage. Don't know if the arrow keys should be used for selecting the finer steps, maybe a short press on "Fine" selects 1 V and 0.1 V, and a long press on "Fine" selects 0.01 V steps. Shouldn't be much work to implement it. And fixing the problem with the wheel that it misses counts when turning fast would be nice, too. Then it would be a perfect power supply for meChanging the display format is a matter of taste, I can live with the current concept that it shows the set value when you turn the wheel and after a timeout the output value.

author: leonerd
author_rank: Regular Contributor
timestamp: October 23, 2015, 12:11:24 pm
content: Quote from: FrankBuss on October 23, 2015, 11:44:20 amThe latest firmware can be found by searching inhttp://www.siglent.com/ENs/gjjrj.aspx?id=15Specfically, the file required seems to live currently athttp://www.siglent.com/ENs/gjjrj-xq.aspx?id=1019&tid=15I don't know of a program to update it, other than the original Windows control software supplied on the CD with the PSU.The firmware updates don't appear to come with a list of changes or release notes, so it's hard to tell what's been changed.

author: leonerd
author_rank: Regular Contributor
timestamp: October 26, 2015, 02:16:43 pm
content: As promised earlier, here's a couple of quick mockups of what I think would improve the UI a bit. It shows both setting and readout value all the time. The first image shows Channel 1 turned on, giving both the setting and readout values. Channel 2 is switched off.The second image shows the display during editing - someone has rolled the setting wheel to adjust the voltage level. Additionally, when you're editing a value, you're editing one digit at once - the idea with this UI is that those left/right buttons would move the cursor left or right.The Korad KA3005P is a good example of this - that lets you adjust the voltage in units of 10V, 1V, 0.1V or 0.01V. It applies wraparound to the higher digit. E.g. if you're currently editing in 0.1V steps then rolling the wheel moves from 2.80V, 2.90V, 3.00V, 3.10V, ...

author: leonerd
author_rank: Regular Contributor
timestamp: October 26, 2015, 02:53:21 pm
content: Another idea, if there's sufficient spare CPU bandwidth and refresh rate on the display, is to add an analog bargraph to the readout sections. This way, you could easily see the actual voltage / current level as a fraction of the target setting. The intention here would be that the bargraph is updated a lot more frequently than the rest of the screen - ideally something around 10 to 20 frames/sec if the measurement hardware and management CPU can manage it.The bars here are currently green, but if the measured reading too high; say, more than 1% over the set target, they'd turn red.There aren't many programmable power supplies that have an analog bargraph to their readout - I think this could be a really nice addition here, and quite a distinguishing factor.I've also adjusted sizes a bit, making the Set area smaller, to give the Read area some more space.

author: Unknown
author_rank: Unknown
timestamp: October 26, 2015, 05:21:29 pm
content: Thanks for your suggestions Leornerd.I will forward your ideas to Engineering with the suggestion that we display both programmed and actual output levels at the same time.

author: leonerd
author_rank: Regular Contributor
timestamp: October 26, 2015, 05:47:30 pm
content: Excellent - thanks "Siglent America". Feel free to point people in my direction if you want more clarification on the idea, or if something's unclear.And thanks for taking the time to reply; I know some companies wouldn't even bother. It's good to see someone's listening

author: Unknown
author_rank: Unknown
timestamp: October 27, 2015, 01:29:33 pm
content: Hi Frank.I sent your suggestion and drawings to Engineering and received this response from the VP of Engineering- below.Thanks again for your good suggestions!Steve<<<<Hi SteveThe guy's suggestions are good. I very like this kind of feedback. I will remember his name,LeonerdThe suggestion of improve the control way of setting knob, we had implemented the similar way as he suggesed in new SPD3000X power supply.About suggestion of display the set value and actual output value in the screen at same time, we think it is a good idea. I had discussed with Owen and our enigneer , and we will implement it in the next SPD3000X firmware.Very thank you for monitoring the EEVblog and forward this kind of feedback and some review video and big issues to us. It is a very good commnication way with customer, and can help we improve our products.

author: rosbuitre
author_rank: Regular Contributor
timestamp: October 27, 2015, 01:35:16 pm
content: Quote from: Siglent America on October 27, 2015, 01:29:33 pm

author: leonerd
author_rank: Regular Contributor
timestamp: October 27, 2015, 10:34:55 pm
content: Quote from: Siglent America on October 27, 2015, 01:29:33 pmHi there,Thanks for taking the time to look into this. I have one question though - would this feature only be added on the X version of the PSU, or will it be available on the D as well?

author: Unknown
author_rank: Unknown
timestamp: October 28, 2015, 12:24:43 pm
content: Leonerd,The C/D/S models use different FW than the new X/X-E models.Your suggestions will only be implemented in the new X/X-E models for now. If there is enough demand for the change on the C/D/S versions then we will certainly look at doing it on those as well.Because the new X-Series power supplies are only a few dollars more than the C/D/S models then then the D/S models will probably fade away. The LED version (C) is less expensive so I anticipate it will be around for a while. Of course, it doesn't hacve the larger LCD display so it cannot display as much information at once as the other models.Thanks again for your suggestion!Steve

author: leonerd
author_rank: Regular Contributor
timestamp: October 28, 2015, 12:59:41 pm
content: Quote from: Siglent America on October 28, 2015, 12:24:43 pmIt's understandable that the different series use different FW - I understand the X version has ethernet, so probably a different MCU inside, could be all sorts of other internals changed. But given the UI looks so similar in both cases, the idea itself should work fine either way.You say "a few dollars more" - I see on siglent.eu the D version for €299 vs the X-E at €370 - that's not "a few dollars", that's nearly a third more. For the 1mV version, the S costs €399 vs the X at a massive €509. That's quite the difference there.If you're saying you won't be further maintaining the D and S versions, then you may lose out on a portion of the market like hobbyists such as myself, who don't care about ethernet connection. If you are intending to discontinue the D/S versions, then I'm a little disappointed at having only just bought myself a new one.

author: Unknown
author_rank: Unknown
timestamp: October 28, 2015, 01:12:15 pm
content: I don't have the international pricing handy, but only that for North America.SPD3303C: $289SPD3303D: $369SPD3303S: $529New SPD3303X: $539 ($10 more than the SPD3303S)SPD3303X-E: $389 ($20 more than the SPD3303D).And you are correct on why we changed the MPU, Leonerd.With so many new products having just come out and more new ones coming soon then the Engineering manpower has to be considered, where to spend the Engineering resources. If enough customers with the D/S versions want the upgrade then we will certainly look at doing so.if you would like to send me a PM with where an when you purchased your unit then I will pass that on to our appropriate people.Steve

author: leonerd
author_rank: Regular Contributor
timestamp: October 28, 2015, 01:31:28 pm
content: Quote from: Siglent America on October 28, 2015, 01:12:15 pmAh; I see. In that case, that looks a much more reasonable proposition - plus I see the specs on the X/X-E are a little better, as they seem to have higher accuracy voltage/current measurement. At an almost-unbelievably good 0.03% on voltage and 0.3% on current - are we quite sure this isn't a typo?Quote from: Siglent America on October 28, 2015, 01:12:15 pmI can certainly understand the idea of not spreading resources too thinly, and trying to keep a smaller range of different products. I was just concerned at the difference in cost for new features people may not want; but it seems from your US list prices the difference isn't so bad. Maybe the distributor I was quoting my prices from are just trying to shift some of the "older" model a lot cheaper, to get rid of them...

author: leonerd
author_rank: Regular Contributor
timestamp: October 28, 2015, 01:44:09 pm
content: Quote from: leonerd on October 28, 2015, 12:59:41 pmI may retract that in fact; I was looking at just one supplier, who I think may have been selling off older stock cheaply. Looking at other places, I can find sellers offering the X-E for literally the same price as the D. E.g. in the UKhttp://www.tester.co.uk/process-and-industrial/industrial-test-equipment/ac-dc-power-supplieshas both for £269 currently.

author: FrankBuss
author_rank: Unknown
timestamp: October 28, 2015, 03:21:58 pm
content: Upgrading the D version firmware would be nice, because I have a SPD3303D. But it doesn't need to be all changes like for the X version with different GUI, if this is too much work to backport. Just a small change to somehow change the voltage in 0.1 V steps and I would be happy. Could be even a very small patch to adjust it in 0.1 V steps *instead* of 0.01 V steps, because so far I didn't need 0.01 V steps, but often 0.1 V steps, which the firmware programmer could do in a minute.

author: leonerd
author_rank: Regular Contributor
timestamp: October 28, 2015, 04:27:45 pm
content: Quote from: FrankBuss on October 28, 2015, 03:21:58 pmI don't think that would fly with most usersI for one would still like to access the full resolution of voltage setting that the hardware supports; I'd just like a quicker way to enter the numbers.

author: Salas
author_rank: Frequent Contributor
timestamp: November 24, 2015, 08:38:13 am
content: Quote from: leonerd on October 28, 2015, 04:27:45 pmI have the S model and yes I agree, a way to shift through all the digits with the knob is the best approach. Siglent not planing to give the older SPD series any further software upgrade is a big disappointment. Those are recently bought expensive enough units. At least the all digits can shift to set issue must be addressed.By the way, in my S there is always a 2mA residual measured and displayed without anything connected in all modes except in the parallel mode. Along with the resultant power displayed. It keeps on adding when more current is drawn by some load, its not just a ghost before connecting. Do you guys have that thing in your units? Or some annoying green red light cycling and relay clicking on CH2 when having PARA pressed and the outputs activated before connecting a load?Also the rotary started shuttling the setting with no tactile feel as to why or in any steady pattern. Almost burned an expensive circuit I was testing when I tried to go from 14V to 15V and it flown to 19V with just one click to the right. Saved it being quick on the off button. Going higher instead of lower when turning to the left sometimes even. I think I remember no shuttle mode or it was more disciplined a few months ago when I bought it. Some more accurate following of the rotary movement must be addressed. Else its dangerous to try step it live. At least in mine.

author: DSoldano
author_rank: Newbie
timestamp: January 14, 2016, 12:10:52 am
content: Well, I'm having an interesting problem with my SPD3303D. I never tested it originally other than a power on test and then it stood in the closet for a while. I am working on a programmable DC load project and was using the SPD3303D as the circuit power supply (using the fixed 5V output) and also as the source input for the load - Channel 1 - set to 5v and 1A max at this point to limit the power and avoid magic smoke since I haven't mounted anything to a heatsink yet.I noticed that every time I get above about 100 ma draw the voltage readout on my circuit was dropping. I thought it was a problem with my circuit until I put a handheld multimeter on the output. My circuit is fine. The voltage starts to drop off after 100 ma although the display on the power supply still shows 5V. at about .5A the power supply voltage drops off to about 4.85V yet the display still shows 5V.Anyone notice a similar issue? Am I doing something wrong? If it's the power supply that's pretty crappy regulation with such a small percentage of the full current potential.Dominick

author: FrankBuss
author_rank: Unknown
timestamp: January 14, 2016, 12:45:28 am
content: Quote from: DSoldano on January 14, 2016, 12:10:52 amDid you measure it at the connectors at the power supply or at your circuit? Could be losses in the cables.

author: DSoldano
author_rank: Newbie
timestamp: January 14, 2016, 01:00:40 am
content: Frank,Thanks for the quick response. I measured it at the terminals and at the circuit. I used the same brand of cables both for the meter and from the power supply to the circuit. Voltage read the same in both cases. If it was cable losses they should have been cut in half when I measured at the power supply terminals since it effectively reduced the length of the overall cable by half.I have the mains/line voltage selector switch set to 120V on the back of the meter - I'm used to equipment labeled 110V/120V in the US but this doesn't have a 110V setting only 100V or 120V. I'm tempted to see if it's a low voltage problem and try the 100V setting but I don't want to blow up the supply.Dominick

author: FrankBuss
author_rank: Unknown
timestamp: January 14, 2016, 03:54:42 am
content: I can't reproduce the problem. I set 5 V for channel 1 and 1 A max, connected a 10 ohm resistor with some thick test wires, 1 m long each, and I can measure 4.97 V at the resistor and 4.999-5.0 V at the terminal (measured directly at the washers on the front panel). It is configured for 230 V. Mains voltage is 226 V (true RMS, all measured with a BM257s).I think it should work with the 120 V setting, usually there is some safety margin and then it should only show problems with higher voltages, if it is not some low-voltage tap at the transformer which is right at the edge between two ranges. 100 V should not blow it up, it just gets a bit warmer. Try to measure your mains voltage (carefully, with a good meter).Dave did a review of the SPD3303X and there were issues with the banana plugs. The socket was slighty too wide, so some banana plugs are a bit loose in it and this caused some voltage drop, too, if you wiggle it.

author: DSoldano
author_rank: Newbie
timestamp: January 14, 2016, 03:24:16 pm
content: Frank,I tried checking the contact between the banana plugs and the binding posts - they are pretty tight and wiggling them provided no change.I even switched to the spade lug cables that came with the unit to be sure. Same behavior as earlier - it appears to drop off from 4.98V no load / open circuit to 4.78V at 1.2A. I tried both channels. The behavior is the same on both Channel 1 and Channel 2. I even tried running the channels in parallel - same behavior. The display on the SPD3303D reads 5.00V throughout the whole exercise, never wavers although the current reading changes.I also tried changing the power setting in the back of the unit from 120V to 100V. The fan gets a bit louder but otherwise exactly the same behavior.I'm not sure if I should bother trying a firmware update or not or just contact Siglent.Dominick

author: FrankBuss
author_rank: Unknown
timestamp: January 14, 2016, 05:04:53 pm
content: Sounds like your unit is broken, but warranty should cover this.

author: Renae
author_rank: Newbie
timestamp: March 14, 2016, 07:27:00 pm
content: Quote from: Siglent America on October 27, 2015, 01:29:33 pmHi Steve,Thanks for getting out there and answering questions about your products.I see there appears to be a firmware that was released just before your post above and I suspect the update you are referring to would be in the next update. Do you know when there will be another firmware update for the X series implementing the aforementioned graphical update? I too would find it immensely useful to see the current setting in addition to the current reading. I'm also curious about adjustment in the hundredths. I was looking at the D version just before purchasing and I saw there was an update in January for the D version but for some reason I did not check the X version. Well, I changed my mind to get the X version partially based on your post. I just now checked the X firmware date and saw, as mentioned above, there has been no update for a while.Thanks again

author: Unknown
author_rank: Unknown
timestamp: March 15, 2016, 12:49:38 pm
content: Hi, FrankBuss, Ranae, and others.We are about ready to release the new FW that shows both the programmed settings as well as the actual output values.We'd like your opinion on which screen User Interface you prefer. Please see the three attached screen shots and let us know which one you prefer (UI-1, UI-2, UI-3) and we will use that one in our new FW.ThanksSteve

author: rosbuitre
author_rank: Regular Contributor
timestamp: March 15, 2016, 12:58:16 pm
content: Quote from: Siglent America on March 15, 2016, 12:49:38 pmUI-1regards

author: Chupacabras
author_rank: Regular Contributor
timestamp: March 15, 2016, 01:04:45 pm
content: Quote from: Siglent America on March 15, 2016, 12:49:38 pmI have SPD3303X-E and any of those 3 options are better than current one.I like UI-3and UI-2.(edit: I think UI-2 is less logical according to physical connectors than UI-3)But I have a challenge for you: make it changeable in setup so user can choose any of it

author: rf-loop
author_rank: Super Contributor
timestamp: March 15, 2016, 03:44:32 pm
content: 1. UI-12. UI-34. UI-2 because outputs are horizontally but display is vertically...Other things.Please add user selectable monocolor amber also. Not all peoples want lab as "Hong-Kong" street with all different colors and lights. Also because some lab environments are not very bright. It need some kind of "night vision" mode. Also, if it is possible to add even some brightness adjustment. My opinion is that it is not too difficult to add user selectable things to small settings menu what can call with simple keystrokes etc. (if there is any room in memory)Then: Please bruteforce someone in factory enough hard that they change outputs binding posts spacing so that it meet "standards" if they do not have this already in new production. Standard distance is 19.05mm (3/4 inch) and nothing else. It iss not 19.5, it is not 20, it is not 18.5. It is exactly and only 19.05mm. Period. All double plugs have this. Who is response about wrong distance. Designer need know what he is doing. I have noted this long long time to Siglent but it was like talking to walls.

author: Zbig
author_rank: Frequent Contributor
timestamp: March 17, 2016, 11:52:24 am
content: I like UI-3 more than UI-1. Rounded corners seem dated.

author: Unknown
author_rank: Unknown
timestamp: March 17, 2016, 01:02:02 pm
content: Thank you to everyone that voted.#1 and #3 seemed to be the most popular. The factory sent me new FW with #1 in it but it was not the official release.I will pass on the results of our little survey to them. I expect the FW update to show up on our website very soon.

author: Helix70
author_rank: Unknown
timestamp: March 21, 2016, 03:32:31 am
content: We just bought some SPD3303X-E's. What is the current firmware, and when is the new one due for release?Josh

author: tautech
author_rank: Super Contributor
timestamp: March 21, 2016, 06:31:16 am
content: Quote from: Helix70 on March 21, 2016, 03:32:31 amGood question Josh.There's been no new FW for these PSU's AFAIK, there no sign of any on the Siglent FW pages:http://www.siglentamerica.com/support_software_15?page=1So that means the FW they've been supplied with is still current.Do you have an issue that needs looking at?

author: Unknown
author_rank: Unknown
timestamp: March 21, 2016, 12:24:15 pm
content: Good morning.I don't have an exact date on the new FW but I do know if has the new screen that shows both the programmed (set) values as well as the actual output values. I believe it should be out any time and I will check on it. Please be watching for it atwww.SiglentAmerica.com.Steve

author: Helix70
author_rank: Unknown
timestamp: March 22, 2016, 12:42:09 pm
content: I do, but I don't think it is a firmware issue. We bought 3, and one of them has locked up after going into screen saver, and on power up, either all the lights are on and they don't go off, or they are off and they don't go on. It is weird. Channels are still controllable, but they don't look like they are. Sometimes a button press changes all the lights to off, or on.

author: tautech
author_rank: Super Contributor
timestamp: March 22, 2016, 08:24:06 pm
content: Quote from: Helix70 on March 22, 2016, 12:42:09 pmSiglent Tech support has been linked to your reply, please keep us posted as to the outcome.

author: Helix70
author_rank: Unknown
timestamp: March 22, 2016, 08:46:28 pm
content: Thanks. I emailed the supplier yesterday, so will see how they want to go. Not my week, first they were delivered to the wrong address, now a funny one (of course the one I set up on MY desk!)

author: tautech
author_rank: Super Contributor
timestamp: March 23, 2016, 10:18:07 am
content: Quote from: Helix70 on March 22, 2016, 08:46:28 pmHere's that new FW you inquired about:http://www.siglentamerica.com/USA_website_2014/Firmware&Software/firmware/SPD3303X-E-P02.02R2.rar

author: Helix70
author_rank: Unknown
timestamp: March 23, 2016, 10:31:38 pm
content: Charles from the Siglent dealer here in Australia, Trio Test and Cal dropped in yesterday and picked the suspect unit up.The problem was intermittent (of course), and seemed to be mainly to do with the LEDs behind the buttons. They would just not operate when the buttons were pushed, or they would stay on when the buttons were pushed. Other functions all worked as expected, despite the indications of the LEDs. There was also one instance of freezing when left on after entering screen save, so perhaps a faulty connector or solder joint.My new unit should arrive shortly. Thanks for the great response!

author: xyrtek
author_rank: Regular Contributor
timestamp: March 24, 2016, 02:43:12 am
content: Quote from: Siglent America on March 15, 2016, 12:49:38 pmGlad to see Siglent is listening, well done. There are probably more customers to be had than just the ones that post on the forumI like UI-2 but, why not make them all available and let the customers decide? Asking for a friend.

author: tautech
author_rank: Super Contributor
timestamp: March 24, 2016, 02:53:15 am
content: Welcome to the forumxyrtekNice collection of new Siglents you have.Spend some time here and you'll see a few of us watching.

author: xyrtek
author_rank: Regular Contributor
timestamp: March 27, 2016, 06:40:25 pm
content: Quote from: tautech on March 24, 2016, 02:53:15 amThank you.Happy to oblige

author: poundy
author_rank: Contributor
timestamp: April 06, 2016, 11:57:14 am
content: I am in two minds about posting in this thread or creating my own - well I guess this won outHave been thinking I need a bench power supply better than my dodgy $10 ebay thing that runs off a wall plug and even with the quirks the Siglent seems to come out on top of the lower priced bunch. Well except perhaps for the banana plug thing; that's pretty unforgiveable really.Anyway, the SPD3303C and D caught my eye because they're in a "comfortable" price point. Justifying more than the AU$440-$500 that they would turn out to be is harder to do to the financial controller - after all I am only a hobbyist, so it's probably hard to convince myself to go higher too! So that's why I came to you all, to convince me why I should go up the scale.Here's Trio's (inc GST) pricing at the moment.....C $439D $481S $655X-E $720X $974I won't need 1mV or 1mA resolution, 10mV/10mA is fine. The graphical display of the D and X-E are nice, but for me not essential, so I totally can get away with the C. Since the price delta of the C and D is so minimal, and the benefit also so trivial, I can't see any compelling reason to go for the D version, EXCEPT if the UI changes noted earlier are also coming for the D because if the D is also getting the UI tweaks, then I'd opt for it. Given the X and X-E firmware was out a few weeks ago, and the D and S models haven't seen an update since early 2015, I guess I know the answer (but I'm hoping the Siglent team watching these threads step in and say different).So, anyone point out logic flaws in the above? I can't really see the value in stepping from a sub-$500 unit to a $720 unit just to get both the setpoint and actual readings (as much as I would want that)....One final thing, has anyone seen a vid of the C unit in action adjusting values? I'd be interested in seeing how quickly it goes from setpoint to reading as that might make it seem laggy when using it. Or if anyone has one and wants to video it, youtube awaits

author: Helix70
author_rank: Unknown
timestamp: April 06, 2016, 08:57:55 pm
content: In Dave's review a while back, he noticed some loose 4mm sockets. This was rightly critisiced by him, and in here.On our power supplies (recently purchased SPD3303X and SPD3303X-E *2) all of the 4mm plugs that I tried fit normally. That includes the shrouded to non shrouded adapters, our stackable 4mm leads from Jaycar, and a some other random ones. None of them feel loose. Perhaps they fixed this?They are still non standard spacing, but this isn't all that important to me to be honest.With the new firmware, the display makes much more sense, and can set the set points independently of the measured output. It is also worth noting that the 2.5/3.3/5V channel is overload protected, but the current limit is not adjustable. A pity, but you do have 2 other channels with full control.This PC software is functional, but not great (being kind here - come on Siglent, it needs more than a day's work).Overall, happy.

author: poundy
author_rank: Contributor
timestamp: April 06, 2016, 09:33:51 pm
content: Thanks. You haven't tried to convince me on sending more cash Trio's way.... but you have watered the seeds already planted. Its unlikely that D and C models will get any love since they're "old", that may also include being manufactured with older stock posts etc and so the issue may be evident.... but if I am going to hand out $720 then that brings back into play some of the GW-Instek models into the decision, and maybe even the Rigol.... sigh, more research needed. Or just buy the C and be done with it

author: AlexDavidson
author_rank: Contributor
timestamp: April 22, 2016, 12:56:04 am
content: I too am looking at the Siglent SPD3303 models, but would only consider sending cash Trio's way if they were a bit more realistic on price. In the US the SPD3303X-E is about 15% cheaper than the Rigol DP832, but from Trio the SPD3303X-E is actually priced higher than the DP832 from Emona. AU$720 doesn't compare favourably against US$389 for the SPD3303X-E, even taking the low exchange rate and GST into account...

author: poundy
author_rank: Contributor
timestamp: April 22, 2016, 04:04:58 am
content: Quote from: AlexDavidson on April 22, 2016, 12:56:04 amI have to agree, the DP832 went to the forefront of my list once I started to convince myself that spending that amount of cash made sense.... although I've bought a few parts on ebay to get me out of the immediate need I had (plus I'm a cheapa$$, and it'll probably be100% better than the collection of dodgy transformers I have today)

author: Helix70
author_rank: Unknown
timestamp: April 26, 2016, 03:27:01 am
content: Quote from: AlexDavidson on April 22, 2016, 12:56:04 amIf you are serious, give Trio a call. You never know...

author: Salas
author_rank: Frequent Contributor
timestamp: October 16, 2016, 01:19:39 am
content: My SPD3303S developed an issue where the control knob wouldn't respond normally any more but jumped around the setting like crazy when stepped. Using PC software control all was still setting fine though. Jonas from Siglent.eu shop responded nicely and communicated with the factory. After I filled a fault description form they decided to send me through Jonas a new front face control board to replace. The whole thing was done not too slowly and was free of charge because the unit is under warranty.Its not a quick job because it takes many disassembly steps that is why I postponed it for a while as the PSU was used to finish a project. Anyway I took it apart today and I exchanged the boards. I am happy to see that it now works correctly again. Thumbs up to Jonas and Siglent for thatGiven the opportunity I wonder if Siglent has more time now to allocate into updating the S series firmware for 1V knob stepping too and not only 0.1V coarse or 0.001V fine? Its a serious drawback in manual operation for the S not having a 1V coarse also. Manual is the most frequent mode of use on a bench after all. It should be starting at 1V coarse then press fine to 0.1V or long press fine to 0.001V. Even better some combination of fine and arrow keys to select any digit from first to last.Split screen set and out sections would be also nice like they did on the X after listening to our feedback here but lets not ask much. There is a large base of D/S series users and retro-fixing some ergonomic issue surely gives to a company a boost in customer loyalty. Its just a control fix in software, nothing too hard.

author: mimmus78
author_rank: Unknown
timestamp: October 17, 2016, 06:24:09 pm
content: I have a similar problem: if turn knob very fast voltage may jump 10V or even more volts (and burn what you are working for).Don't know if is just a "chinese special feature" or a defect.Anyone have noticed it?Inviato dal mio Nexus 6P utilizzando Tapatalk

author: Salas
author_rank: Frequent Contributor
timestamp: October 17, 2016, 11:57:19 pm
content: It does not have a shuttle mode. I think that we simply prematurely wear out the rotary encoder because we can't select the 10V digit or its next 1V so we spin it a lot to go up and down the full 32V available. My Korad/Tenma budget supply can do it. Has a Voltage/Current shift button, then with the arrow buttons the flashing digit to be changing value with the rotary, changes. So the Siglent with immensely more powerful DSP could also do it if they planned so. But they likely thought USB control would be the primary way and the rotary for small adjustments. Wrongly thought out if so. Manual is the primary mode of operation on a bench.

author: FrankBuss
author_rank: Unknown
timestamp: October 18, 2016, 01:00:14 pm
content: I think in one of Dave's videos I've seen a power supply where you can set a maximum voltage limit (was it a Rigol?), and you can't accidentally go higher with the rotary encoder. This would be a useful feature for the Siglent as well. There is a lot of space on the display to implement such a feature.

author: tautech
author_rank: Super Contributor
timestamp: October 18, 2016, 06:08:17 pm
content: Quote from: FrankBuss on October 18, 2016, 01:00:14 pmAs far as I can tell Frank, all the Siglent PSU's have a lock feature on the front panel in the form of a Lock softkey.

author: FrankBuss
author_rank: Unknown
timestamp: October 18, 2016, 08:02:39 pm
content: Yes, the lock key is a limited version of the "limit" function which some of the Rigol power supplies have, see minute 18:46 in this video:

author: Salas
author_rank: Frequent Contributor
timestamp: October 21, 2016, 05:01:13 pm
content: Panel keys lock is alright, does the job. The X series have a good enough UI by now too. I like the compact form factor and silent operation of our Siglent vs the Rigol. Also the relays for series. No need for wire jumpers to change modes. I am also happy with the after sales service.A friend has the Rigol and its way too bulky and noisy for me, also the screen characters are small and many. A crowded display. All same color.If Siglent could retro-fix the S series firmware for all digits selection to be changing with the rotary I would be happy. If they could be also adding set and out display sections like on the X it would be perfect. They are the same PSUs except there is also network in the X. That could mean a different controller chip inside though.

author: leonerd
author_rank: Regular Contributor
timestamp: November 23, 2016, 02:18:10 pm
content: Quote from: Helix70 on April 06, 2016, 08:57:55 pmOooh - is that the thing I was suggesting way back a year ago or so? Do you have any pictures you could show us of the new display form?Quote from: Helix70 on April 06, 2016, 08:57:55 pmYeah - I'm really not sure I consider this to be a 3-channel power supply. It's more like 2-and-a-bit. CH3 is not a real channel.

author: nidlaX
author_rank: Frequent Contributor
timestamp: March 16, 2017, 06:40:44 pm
content: Has anyone noticed whether or not the fan speed will drop when you enable the output? I know that the fan speed varies according to the temperature of the main heatsink, but the fan speed on my unit always drops considerably when the output is enabled compared to when it's disabled.It makes me wonder if there is a power rail issue.

author: Zbig
author_rank: Frequent Contributor
timestamp: March 16, 2017, 06:49:48 pm
content: Mine does the same. Perhaps the fan is powered straight from the rectified output to ease on the regulator? Haven't checked, though.

author: nidlaX
author_rank: Frequent Contributor
timestamp: March 17, 2017, 06:19:43 am
content: Quote from: Zbig on March 16, 2017, 06:49:48 pmOk, that sounds plausible and I can accept it.Another issue I've noticed is that my channel 2 is drawing 0.01 A or so when the output is enabled, but not connected to any load. Should I be concerned?Sent from my ZTE A2017U using Tapatalk

author: Zbig
author_rank: Frequent Contributor
timestamp: March 17, 2017, 10:29:43 am
content: Quote from: nidlaX on March 17, 2017, 06:19:43 amAre we talking the "D" or "S" model? If you have "D", then I definitely wouldn't worry about it, 0.01A being the one least significant digit count. I have the "S" model (1 mA resolution one) and both channels show (different) few mA of current values when enabled but unloaded after cold start. They then drop to few (sub 10) mA after some time, as the thing heats up. It's rather easy to check the manual whether yours still in specs or not (I don't have it on hand now).

author: Helix70
author_rank: Unknown
timestamp: March 20, 2017, 01:02:56 am
content: Anyone know a way to recover the SPD3303X after a failed firmware update bricks it? Nothing at all on power up now.I tried the firmware update on advice from Siglent after having front panel lockups. It is under warranty, and Trio are fantastic, sending me a loaner while mine is being fixed, but would like to recover it if it is straight forward.

author: Zbig
author_rank: Frequent Contributor
timestamp: March 20, 2017, 10:48:26 am
content: Quote from: Helix70 on March 20, 2017, 01:02:56 amIIRC, you put it in the bootloader mode by holding the rotary encoder pressed while powering up. Then you'll have to choose "bootloader mode" in the supplied software while uploading the firmware file.

author: tautech
author_rank: Super Contributor
timestamp: March 20, 2017, 06:20:13 pm
content: Quote from: Zbig on March 20, 2017, 10:48:26 amFor one I updated recently, I had to install the EasyPower PC control utility and install the new FW via that. It seemed the only way mentioned to update the X series PSU's, The process was quite straightforward and painless enough. The X series PSU screen displayed an "updating" message while it was and IIRC another to restart the PSU when finished.

author: mimmus78
author_rank: Unknown
timestamp: March 20, 2017, 07:07:25 pm
content: Prematurely wear out? Not at all, I have others Agilent power supply and almost never used this Siglent one.When he developed the problem was almost like new ... Now I learned to turn off the channel before changing voltage, but this is not always possible.Anyway it should be a safety (for the circuit you are working on) to not ever jump like this. It doesn't even have acceleration implemented ...It also has the USB tmc bug that was never solved. You get what you pay for.

author: Helix70
author_rank: Unknown
timestamp: March 21, 2017, 06:51:26 am
content: Quote from: Zbig on March 20, 2017, 10:48:26 amThanks, that worked. I also had to reinstall the NI-VISA drivers, mine had gotten corrupted somehow. FYI, don't do the update via a USB hub, or you may brick it. Direct connection worked. Now I can wait and see if the update fixed my panel lockups!

author: nidlaX
author_rank: Frequent Contributor
timestamp: January 03, 2018, 11:42:04 am
content: I'm sure anyone who cares has already figured it out, but it's quite trivial to upgrade the 3303D to the S version. Simply open the S version .ugf file in a hex editor (or maybe notepad) and change the 'SPD3303S' header to 'SPD3303D'. (EDIT: Ooops, I had that the other way around...)Of greater interest is upgrading the S version to the X version firmware. After comparing some pictures, it looks like the D/S controller board is very similar to the X/X-E one. A quick look at the .ads format firmware for the X version suggests that it is indeed built on the same foundation as the D/S firmware, with 3303D and 3303S strings still intact. Unfortunately, the .ads format for the power supplies is not quite the same as the one used for the oscilloscopes, so more reversing is needed. Refer to this thread for more info:https://www.eevblog.com/forum/testgear/siglent-ads-firmware-file-format/As always, we would very much appreciate it if Siglent could simply backport some of the interface improvements to the 3303D/S and save us all a load of trouble.

author: jimjam
author_rank: Regular Contributor
timestamp: June 08, 2020, 02:57:43 pm
content: Quote from: nidlaX on January 03, 2018, 11:42:04 amDid you find out more about this?

author: tautech
author_rank: Super Contributor
timestamp: June 08, 2020, 07:57:20 pm
content: Quote from: jimjam on June 08, 2020, 02:57:43 pmNot worth the effort as the X series PSU's use a LCD display vs LED for the old models.My 2c is go for the later SPD3303X-E. They're the only ones I stock now.....so much more info on the home screen:https://int.siglent.com/products-overview/spd3000x/

author: jimjam
author_rank: Regular Contributor
timestamp: June 08, 2020, 11:36:01 pm
content: Quote from: tautech on June 08, 2020, 07:57:20 pmI already have SPD3303D and it has an LCD display

author: tautech
author_rank: Super Contributor
timestamp: June 08, 2020, 11:55:11 pm
content: Quote from: jimjam on June 08, 2020, 11:36:01 pmAh, OK.Dunno what to suggest then for a display upgrade/hack.

author: djeans
author_rank: Contributor
timestamp: October 03, 2021, 09:56:49 am
content: Quote from: nidlaX on January 03, 2018, 11:42:04 amdoes this really work? Any1 tried and gives the 0.000A accuracy ? And where do I get the S firmware. I was only able to find the D FW.thanks

author: Murphy
author_rank: Regular Contributor
timestamp: October 14, 2021, 06:21:49 pm
content: I couldnt find the firmwares for SPD3303D/SPD3303S anywhere live but archive.org does have themhttps://web.archive.org/web/20150908094808/http://www.siglentamerica.com/prodcut-gjjrj.aspx?id=175&tid=17&T=2Just tried the hex edit and successfully flashed the S version of 1.01.01.01.06R2 over the 1.01.01.01.06R1 on an SPD3303D.Extra digits are there now 🥳, but haven't tested much.

author: lugamodder
author_rank: Newbie
timestamp: September 12, 2024, 01:56:47 pm
content: I have an old SPD3303D power supply, which is discontinued but in excellent condition. Firmware version 1.01.01.06R2. "upgraded" to SPD3303S . It has a minor voltage issue on the first channel. Has anyone managed to calibrate the SPD3303D/S? I am using the NI VISA Test Panel and PYVISA lib with the SPD3303X calibration guidehttps://www.eevblog.com/forum/testgear/siglent-sds3303x(-e)-calibration-fw1-01-01-02-07r2-best-practice/with no success. The issue is that after executing the commands "*CALCLS 0" and "*CALCLS 1" correctly, the command "CALibration:VOLTage CH1,1,0.8736" is not accepted, and the power supply beeps. I tried downgrading to SPD3303D, changing the number of decimal places, removing and adding different line-ending characters, but without success. I also tried downgrading the firmware to the only one I found, 1.01.01.03R1, but also without success. The device doesn’t want to update through EasyPower. Has anyone had a successful calibration of such a power supply?

author: KungFuJosh
author_rank: Super Contributor
timestamp: September 12, 2024, 05:03:10 pm
content: Quote from: lugamodder on September 12, 2024, 01:56:47 pmI have the SPD3303X and was able to calibrate it. I used the instructions in the older service manual (attached). The instructions were removed in the newer service manual for some reason. Hopefully it will help your situation.

author: lugamodder
author_rank: Newbie
timestamp: September 14, 2024, 03:16:00 pm
content: Quote from: KungFuJosh on September 12, 2024, 05:03:10 pmThanks, I use almost the same manual but without success, the SCPI command "CALibration:VOLTage " is not accepted by the device in any variations I tried. It seems there are differences between the D/S and X series.

author: KungFuJosh
author_rank: Super Contributor
timestamp: September 14, 2024, 06:39:06 pm
content: Quote from: lugamodder on September 14, 2024, 03:16:00 pmIt was finicky. I looked, but unfortunately I couldn't find my notes on what worked beyond that manual.

author: 伊卡洛斯
author_rank: Newbie
timestamp: September 02, 2025, 09:03:37 am
content: I couldnt find the firmwares for SPD3303S anywhere.Can you send me the firmware for SPD3303S？

author: nidlaX
author_rank: Frequent Contributor
timestamp: September 09, 2025, 12:32:20 am
content: Quote from: 伊卡洛斯 on September 02, 2025, 09:03:37 amFYI, the link from archive.org above still works:https://web.archive.org/web/20150908094808/http://www.siglentamerica.com/prodcut-gjjrj.aspx?id=175&tid=17&T=2