Looking to purchase linear PSU, debating the GPP series - Page 1
Forum section: electronics / testgear

author: adauphin
author_rank: Unknown
timestamp: January 31, 2022, 03:42:03 am
content: I've been waiting until I finished my new workstation for a PSU purchase, and had the Rigol 832 on my radar. I've never been a fan of the rotary style numeric pad and also the depth of the unit may be an issue. I can make the depth work, but a shorter PSU would be a better fit.Having looked at the GW Instek GPP series, I believe these are the ticket.They are not as deep, and have the conventional numeric keypad, again, not deal-breakers, but what I would prefer to have. I can also fit this PSU on 12-13" shelf with the setup I will have.I don't believe I would need a 4- output PSU, but the three I have been looking at are the:GPP-3060GPP-3323GPP-4323Given the slight price difference of the quad-output 4323, are there any limitations to the 4323 over the other two in terms of accuracy or features other than an extra output? Looking at the spec sheet I believe the 4323 would be the better option with room for flexibility.Main tasks are simple circuit designs, audio component designs, and possible small dc motor powering and would like to know what should be used for powering small motors to avoid damage.This is alot of PSU for the immediate tasks, but don't mind spending a little extra for accuracy and to have it serve most of my needs as I expand my projects.I hope I provided enough info, all input and criticism appreciated.

author: kjpye
author_rank: Contributor
timestamp: January 31, 2022, 05:43:07 am
content: The 3323 5V output is rated at 5A, where the 4323 5V output is only 1A. That's probably a bit low for many purposes.

author: ledtester
author_rank: Super Contributor
timestamp: January 31, 2022, 05:48:47 am
content: You might also consider an Owon... here's one Electronics Youtuber's review:New Lab Power Supply -- Jerry Walkerhttps://youtu.be/T4NSx3ekA5kOWON ODP6033 Review -- Jerry Walkerhttps://youtu.be/y7GwdBBidNU

author: jjoonathan
author_rank: Frequent Contributor
timestamp: January 31, 2022, 03:04:02 pm
content: I have a GPP-4323 and I love it. The 1A limit on the 5V channel hasn't been a problem (I mostly use modern chips that sip power), but having 4 channels in the footprint of a single power supply has been an enormous benefit. YMMV, of course.> I don't believe I would need a 4- output PSUDave is probably the only person on the planet who has enough PSUs -- but seriously, 3 is, what, one logic rail and one split rail? They go quick. It's easy to get into a situation where you need multiple logic rails and multiple split rails. You can certainly buy them as you need them, but then you'll run into a situation where you have a collection supplies that all work slightly differently. A single forgotten caveat is all it takes to fry a circuit. Having 4 channels in the same box with the same user interface under the same "enable" button is realllly nice.

author: PeterKlop
author_rank: Contributor
timestamp: January 31, 2022, 03:34:04 pm
content: It seems the GPP-3060 is almost double the price of the other two. It is newer, recently introduced together with the 6030.When designing/modding/repairing audio amps are on your mind, the 6030 (60V/3A) may be preferable to the 3060 (30V/6A). But if you plan to spend that kind of money buying two 3323 instead of one 3060 or 6030 may also be an option, price-wise.I own the GPP-3323 and i like it except it's programmability (that's cumbersome).Two weeks ago i bought the Owon ODP6033 that Ledtester is mentioning. This because i wanted a dual 60V supply for audio-amps testing and i didn't want to shell out the money for the Instek GPP-6030. The Owon was on sale and the videos that ledtester linked convinced me that the build quality was good enough for me and the purpose (normally i'm not an owon fan but these seem to be build decently). So i can say something about that.I haven't however used the owon yet, besides playing with it. The sceen is less contrasty then expected (cheaper, but always good readable), here the instek is better. The buttons on the instek feel also a little better and the instek UI feels just a tad faster to respond sometimes. But this doesn't mean the owon is not good or not enjoyable, that's not what i'm saying. For this kind of money and with the capabilities it has, i'm happy with it (so far) and would buy it again.Both the Owon and Instek make very little fan-noise when not under heavy load. The Owon has a slight transformer hum. Slight; as in; i forget it's there when i'm sitting a meter away doing other stuff then listening for it. I do have the unit in an open cabinet.As to the GPP-3323 vs GPP-4323; The third output of the 3323 is fixed as to it's current limiting (at 5A). The 4323 is fully adjustable in this regard, but can't deliver 5 amps. Something to consider.In terms of voltage accuracy they are all the same.Not accurate down to the millivolt, it differs a few millivolts.**Update:Just got some time to play with the Owon and answered an open question i had with regards to current limiting. It is slower and also irregular in it's response. I pitched it quick and dirty against my Instek GPP and AIM QL355T. For critical work i would choose the Instek over the Owon.

author: nctnico
author_rank: Super Contributor
timestamp: January 31, 2022, 03:49:52 pm
content: I'd go for a PSU which is adjustable (both voltage and current) on all outputs instead of a single voltage, high amp output.

author: mawyatt
author_rank: Super Contributor
timestamp: January 31, 2022, 04:19:02 pm
content: Quote from: jjoonathan on January 31, 2022, 03:04:02 pmThis is so true about having as manyindependantsupplies in one small box being important, especially if you are developing stuff. One thing not mentioned is the real and ever present risk of DUT damage due to supply sequencing, or simply forgetting to turn on supply A before B and so on, please dont ask how I know thisMany complex systems that employ various analog and digital chips and power domains require that all the power rails behave in a certain order, many chips with multiple power rails attempt to protect against this mis-order by means of protection diodes. We try to also utilize external protection means to keep these power rails in order during start up and power down.Having a single power supply with all the required voltages available from a single source make life easier and less risky IMO.We've been working with a system under development that requires a ODA linear supply with +- 120V, +12V, +5V, 3 SDP3303X, and a GPP4323 all utilized at once to create the various system voltages. A custom power supply design reduced this to the single ODA, and later plans are for a custom supply that operates from the 120VAC mains.Best,

author: Hexley
author_rank: Regular Contributor
timestamp: January 31, 2022, 06:54:03 pm
content: Quote from: adauphin on January 31, 2022, 03:42:03 amYes, indeed. With four channels, you can afford to put two in series for 64 volts, or two in parallel for 6 Amps for the occasional high-voltage or high-current loads, yet still have a couple of channels left to power to control circuits. Or, you can use a channel for an active load, and still have three left to provide voltage outputs.As noted above, the low-voltage channel has adjustable current-limiting ability. I use that a lot when bringing up 3V3 or 5V logic for the first time.One suggestion to consider -- the Ethernet option is useful and inexpensive but must be specified as part of the initial order as it cannot be retrofitted. I use it in conjunction with HKJ's TestController software when I want to control the GPP-4323 over the LAN.

author: adauphin
author_rank: Unknown
timestamp: February 11, 2022, 01:51:43 pm
content: Thank you all for your input.I agree the adjustable 4th channel trumps the fixed options despite the lower current rating, I also agree 1A is on the low side.I did see the price on the 3060 after I posted this thread....that would surely change my options at that price point.Many good thoughts here, part of me would possibly consider two 3303's for the price of the 4323, but having only one unit is very nice as well. Sidenote, I love the look of the black Keysight 36300 series and would blend very well in my setup, but again, the price is a bit over budget, especially for 3 channels.It's hard to argue the GPP-4323 at approx $750-760 delivered, was hoping to stick with a sub-$400 PSu like the 3303 but that no-good rabbit hole...I'll sit on all these thoughts for another day I suppose, looks like the GPP-4323 is looking like where I'll end up.

author: mawyatt
author_rank: Super Contributor
timestamp: February 11, 2022, 03:12:50 pm
content: See the GGP-4323 has increased since we got one a couple months ago from Newark (Saelig was out of stock) for ~$600 + tax.The SDP3303X-E is not a bad supply (we have 3), the output is very clean and stable but has a few issues with the non-standard terminal spacing, and the behavior of the UI wrt to the Fine button, and arrowsAlso, be careful doing a self calibration with the SDP3303X-E, follow the procedureexactlyas outlined in the manual, but at least you can do a self calibration which apparently you still can't with the GGP-4323 (maybe GW will give info on this, but asked awhile back and no answer). We hosted up one of our SDP3303X-E with an improper cal attempt, eventually sending in for repair which was done by Siglent NA (Jason) under warrantyThe SDP3303X-E price hasn't changed (yet), so a very good buy in spite of the shortcomings mentioned, and from Saelig you get a 6% discount as a EEVblog memberAnyway, all the PSU you are considering are very good and should serve well.Best,

author: adauphin
author_rank: Unknown
timestamp: February 15, 2022, 03:52:37 pm
content: Thank you all for the help on this.After a few days of back and forth, either saving some $$ and going with one 3303X-E, or trying to justify the cost of the GPP-4323 as I could have two of the 3303X-E's instead.I did go with the GPP-4323 as the discount removed another $40-ish.I also favored the two more variable current outputs, albeit less avail current on them.

author: jjoonathan
author_rank: Frequent Contributor
timestamp: February 15, 2022, 04:07:55 pm
content: I hope you enjoy it as much as I haveIt's unfortunate that prices are up, but that sort of thing is going around these days

author: Hydron
author_rank: Super Contributor
timestamp: February 15, 2022, 05:51:44 pm
content: Just grabbed a few more for work, and they've gone up ~20% in ~6 months with iffy availability (though that was the case earlier too). Glad I got in when I did for my personal unit.

author: adauphin
author_rank: Unknown
timestamp: February 15, 2022, 10:19:44 pm
content: Thanks, and yes, these price increases are spreading like crazy. It came out to about $100 over last year's price, not too terrible but unfortunate. Another one of those "should done it earlier" moments.