DSO Recomendation - Page 1
Forum section: electronics / testgear

author: Gustavo-ar
author_rank: Newbie
timestamp: February 20, 2017, 02:06:01 am
content: Hello! I am new here I am from Argentina so my English is not very good (thanks google translator!), I have been reading a lot in this forum about DSO.I am looking forward to buying an oscilloscope, in my work I would like to measure noise in PSU, PWM signal etc. and as a hobby I am doing something in Arduino and AVR.I was watching this (the prices are in US dollars, too expensive because of my country taxes)Siglent SDS1072CML+ 70 MHz $500Siglent SDS1072CFL 70 MHz $600Rigol DS1054Z 50 MHz $700The first siglent has 2Mb of memory, the second only 24k but has 2Gs / secI do not know which of the two characteristics may be more important for what I'm going to do.I think the $500 siglent is ok with good memory and 7 inch screen, i see a review showing the real bandwith is over 100Mhz, but I was surprised to see a 2Gs/sec DSO for only $100 morehttps://www.eevblog.com/forum/testgear/siglent-scopes/msg222002/#msg222002The third and most complete option is the D1054Z (except for the 2Gs / sec) but I do not know if it's worth the extra $200.Thanks in advance

author: Daruosha
author_rank: Regular Contributor
timestamp: February 20, 2017, 10:00:45 am
content: I understand the prices are quite unreasonable. But the Rigol is more than twice a DSO than DS1072CML+. Save your money and buy something to keep it for a few years. I admit the DS1054 has its own problems, but 4 channel, serial decoders (even on the displayed trace), intensity graded display and so many other options makes Rigol unbeatable in its class.

author: Fungus
author_rank: Super Contributor
timestamp: February 20, 2017, 10:25:00 am
content: Quote from: Gustavo-ar on February 20, 2017, 02:06:01 amFour channels isreallyvaluable for that. It's a big difference.With the Rigol you also get serial decoders, etc. Also valuable for that sort of work.

author: MrW0lf
author_rank: Frequent Contributor
timestamp: February 20, 2017, 03:26:45 pm
content: Quote from: Fungus on February 20, 2017, 10:25:00 amJust word of warning - for analog sort of work where amplitudes and accuracy start to matter this scope is unsuitable. Usable only for general detection of mainly digital electrical phenomenon. Consider this as <10$ multimeter of scopes accuracy wise. I developed deep distrust in mine and it did bite the bullet so to speak... It is tragic you would have to pay so much for one. Maybe source something used and good quality brand locally?

author: Fungus
author_rank: Super Contributor
timestamp: February 20, 2017, 04:32:29 pm
content: Quote from: MrW0lf on February 20, 2017, 03:26:45 pmOscilloscopes aren't multimeters. The written specification for a DS1054Z's voltage measurements are about 5% accuracy at best. It's an 8-bit DAC, it's never going to measure like a Fluke multimeter, it's silly to expect it to. Nobody but you seems to have a problem with the DS1054Z.Quote from: MrW0lf on February 20, 2017, 03:26:45 pmMaybe you could sell yours to him. Kill two birds with one stone. Win-win.

author: MrW0lf
author_rank: Frequent Contributor
timestamp: February 20, 2017, 05:22:26 pm
content: Quote from: Fungus on February 20, 2017, 04:32:29 pmMy scopes are comparable to ~4digit DMM in most horizonal scenarios and ~3digit in vertical. I'm used to that and like the fact very much. 8bit is pretty ok if you apply some averaging and scope has on-the-fly DC zeroing capability. Also Sinc ON|OFF should not change anything.But heres what Rigol does:3.5Vpp, 80MHz pure sine, 500mV/div, 250MSa/s:Sinc=ON: 3.7V => 5.4% errorSinc=OFF: 2.58V => 35.7% errorSo total error between two modes about 40%Naturally "the thing" is long sold... Expecting arrival of vastly superior tech soonWhy is Rigol "performance" ok with many people? First it look like Tek, then it's often first scope and noone knows any better. Also in simple mostly digital domain work analog performance is not that important I guess? Any line ok as long as it wiggles a bitAt the partys also some girl better than no girlBut there are scopes in similar price with vastly better analog performance. Sometimes it makes sense to skip some "features" or "bandwidth" and take a bit more "limited" but excellently implemented device programmed by dudes that visited some decent university not only as touristBut psst... you could get banned on this forum if say too loud what Rigol isMaybe soon the case with Keysight also? I could say a thing or two about 3000 X but skip this time because they just sent me free U1282A and it would no be very polite.

author: rstofer
author_rank: Super Contributor
timestamp: February 20, 2017, 05:30:38 pm
content: Search this forum for DS1054Z and ignore EVERYTHING prior to November 2016 when the latest firmware was released. All discussions about this bug or that bug are invalid as of that date EXCEPT for the spelling error of Pluses instead of Pulses.While searching, pay attention to the trivial process of unlocking 100 MHz, extended memory and decoding options on the DS1054Z. Hint: Search for 'riglol' (note the misspelling).You won't find a scope anywhere near as capable for even twice the price. But, yes, there are better scopes around. They just cost a LOT more money.The DS1054Z is my first DSO so I don't have any frame of reference to compare against other DSOs. But I have had oscilloscopes for about 60 years and while I concede that my Tektronix 485 has more bandwidth and an interesting set of features, in no way can it do the things I can do with the DSO. Single shot mode alone is worth the cost of entry.It's regrettable that your cost is so much higher than here in the US.

author: guenthert
author_rank: Frequent Contributor
timestamp: February 20, 2017, 06:15:30 pm
content: Ok, I bite.Quote from: MrW0lf on February 20, 2017, 05:22:26 pmCare to elaborate how DMMs measure time?Quote from: MrW0lf on February 20, 2017, 05:22:26 pmTake it or leave it, 8bit is very much industry standard for many years and probably will be for a while longer. There are exceptions (I believe some picoscopes have fairly fast wider ADCs and the (comparatively cheap) Digilent Analog Discovery has a 14b ADC (albeit only 100MS/s). Many DSOs (including the 1054z) offer a 'high resoultion' mode, in which they increase the apparent resolution to 14 (or more) bits by reduction.This isn't generally much a problem as long one understands the limitation and purpose of an oscilloscope.A 3% error margin is what analogue 'professional' CROs offered too.Quote from: MrW0lf on February 20, 2017, 05:22:26 pmI give you that, it shouldn't. File a bug report with Rigol.Quote from: MrW0lf on February 20, 2017, 05:22:26 pmYou're measuring a 80MHz signal with a sample rate of 250MS/s?What on earth do you expect?And tell me, which DMM measures a 80MHz signal accurately? My 6.5 digit HP3456a is good only up to about 100kHz, my not quite as ancient HP34401a makes it to 300kHz. For frequencies in the short wave range you'll need specialized gear.Quote from: MrW0lf on February 20, 2017, 05:22:26 pmNonsense, you wont get banned, just laughed out of the house.

author: bsas
author_rank: Regular Contributor
timestamp: February 20, 2017, 06:31:45 pm
content: Hi all,I am also on the market to buy my first DSO! (very excited about it). I want to restart my electronics hobbyCurrently I am playing a lot with analog audio circuits (like guitar pedals for example), so I am very likely yo use a lot of FFT with 100Hz to 25kHz range, but I want to be able to play with digital electronics in the future too.I am very strongly towards the Rigol DS1054Z, and the price looks just too good to be true.I am just wondering if this is the best scope you can get for around $500 or less. I am OK to go a little over if it has some killer(s) feature(s).Thanks all for the recommendations!

author: Gustavo-ar
author_rank: Newbie
timestamp: February 20, 2017, 06:55:08 pm
content: Mostly what I want to measue are SMPS from chargers, desktop motherboards, laptops motherboards, VGA etc.Most of the times the swollen capacitors tell me that there is a problem, but other times at first sight they seem to be ok.That's why I want to measure the noise at the output, to see if it is within normal values.I could throw the old hardware and put a new one, but in many cases being old models I have to change mother, cpu and ram.Also often the noise causes very sporadic crashes that cause me to waste a lot of timeOf course I plan to give it more uses, but that's something I could use "out of the box."I also have some projects as a hobby: a modified atx psu transformed into a variable voltage from 1V to 24V approx., Can also be used as a constant current psu.A component tester with an Atmega328

author: MrW0lf
author_rank: Frequent Contributor
timestamp: February 20, 2017, 07:22:18 pm
content: Quote from: guenthert on February 20, 2017, 06:15:30 pmMy main DMM workhorse - Agilent U1272A has frequency, pulse, duty up to 100kHz. Fairly ok to work with mechatronics. Here is test where I compared Rigol & Pico & Agilent DMM at measuring 666.666666Hz square with 66% duty:https://www.eevblog.com/forum/testgear/testing-dso-auto-measurements-accuracy-across-timebases/msg1096096/#msg1096096Quote from: guenthert on February 20, 2017, 06:15:30 pmIf get to know instrument, it can usually do much better than spec if does not mess with raw data. Most decent scopes try hard not to.Quote from: guenthert on February 20, 2017, 06:15:30 pmI have gotten zero response to bugs filed directly to Rigol (both US & EU). Interesting if at least something will be fixed in next FW...Quote from: guenthert on February 20, 2017, 06:15:30 pmSampling rate is irrelevant if averaging long enough (or using ETS), as long as above Nyquist. I did comparable scaled test on normal scope. No problems. Data points pile up and you get true reflection of analog frontend performance. Decent frontent has predictable performance. So no, I do not need some "specialized gear", just need decent scope and some basic dB calculus.Quote from: guenthert on February 20, 2017, 06:15:30 pmI actually did get banned in the middle of quite civilized discussionhttps://www.eevblog.com/forum/testgear/rigol-ds-1054z-or-tektronix-2440/So... psstMy recommendation is GW Instek if knobs are a must, or Pico otherwise. With GWI you lose decoding and "on paper" bandwith. With Pico only bandwith (load of decoders included). But actually they seem to go much higher bandwith than spec + if you buy Pico MSO thencan "hack" up to 16bit accuracy additional analog channel using digital inputs + math formula + Arduino etc.Edit: Look DC gain accuracy of properly engineered scope:https://www.eevblog.com/forum/testgear/lecroy-waverunner-lt-224-review-and-(partial)-teardown/msg205402/#msg205402In fact, this is interesting subject - so I ordered some voltage references and plan to compare all DMMs & scopes I have at hand, thats >10 units so should be interesting.

author: rstofer
author_rank: Super Contributor
timestamp: February 20, 2017, 08:51:21 pm
content: I don't know much about scope accuracy, it simply isn't important +- a few percent.But I have a calibrated DMMCheck device so I thought I would check my DS1054Z:DC Volts Calibrated = 5.0000V Measured On Scope = 4.99VavgAC Volts Calibrated = 4.9989V Measured On Scope = 5.00V at 100 HzFrequency Calibrated = 100.004 Hz, Measured On Scope = 100.005 HzFrequency Calibrated = 10.0004 kHz, Measured On Scope = 10.0005 kHzI suppose I could use my DP832 power supply to generate other voltages, verify them against my most accurate, but not currently calibrated, Fluke 189 and see how the scope performs over a range but I won't bother. If I had a signal generator that went high enough, I suppose I could try the frequency response of the scope but I don't have the signal generator and I certainly don't have a DMM that would measure AC accurately (like to 4 decimal digits).All I need is wiggly lines plus or minus a few percent. If I need bandwidth, I'll use my Tek 485 and have no measurements of any kind.

author: MrFox
author_rank: Contributor
timestamp: February 20, 2017, 08:53:26 pm
content: Quote from: bsas on February 20, 2017, 06:31:45 pmIf FFT is going to be among your most useful tool, make sure you ask DS1054Z owners opinions about this specific feature. I love my DS2072 on most aspects, and the DS1054Z is newer so maybe they improved on this, but IMO Rigol's FFT implementation is just plainly horrible. (to express myself mildly).

author: Fungus
author_rank: Super Contributor
timestamp: February 20, 2017, 08:54:34 pm
content: Quote from: bsas on February 20, 2017, 06:31:45 pmThe Rigol's FFT is a weak point.There's a 'scope by GW-Instek that actually costs a little bit less than the Rigol and has a better FFT - the GWS 1054Bhttp://www.gwinstek.com/en-global/root/Oscilloscopes/Digital_Storage_Oscilloscopes/GDS-1000BThe (unlocked) Rigol is better for just about everything else. Take your pick!

author: rstofer
author_rank: Super Contributor
timestamp: February 20, 2017, 09:01:22 pm
content: Quote from: guenthert on February 20, 2017, 06:15:30 pmFluke 189 will measure frequency up to 1 MHz, Duty Cycle between 10 and 90% and pulse width to 1 Sec with a resultion of 0.1 mS or to 0.5 Sec with a resolution of 0.01 mS. Not stellar performance as a counter but adequate in many cases.http://assets.fluke.com/manuals/187_189_umeng0200.pdf

author: rstofer
author_rank: Super Contributor
timestamp: February 20, 2017, 09:30:52 pm
content: Quote from: Fungus on February 20, 2017, 08:54:34 pmAhmen on the Rigol FFT - it's much improved but still not stellar. The good news, for me, is that I have done Fourier Analysis exactly ONCE since I graduated in '73. It just isn't important - to me...If I were just starting out and my frequencies (and voltages) were moderate, I would skip all the scope stuff and buy the Digilent Analog Discovery. It has a bunch more capability at a far lower cost. Two channel scope, two channel arbitrary waveform generator, dual adjustable power supplies (won't replace a good bench power supply but adequate for lower voltage projects), 16 bits of digital IO that can also be used as a logic analyzer, a network analyzer (freq and phase response of two terminal networks) and it does a decent job of FFT. Besides, it is running on the BIG screen - 27" displays are way better than 5" displays.http://store.digilentinc.com/analog-discovery-2-100msps-usb-oscilloscope-logic-analyzer-and-variable-power-supply/I have attached a sample FFT from the Analog Discovery and the DS1054Z. Remember, I don't really know much about these displays, I never use them. The settings are probably less than optimal. The Analog Discovery is generating the 1 MHz square wave

author: MrW0lf
author_rank: Frequent Contributor
timestamp: February 20, 2017, 09:33:53 pm
content: Quote from: rstofer on February 20, 2017, 08:51:21 pmSo as you can see, scopes can be pretty decent with DC. For many scopes this carries to HF AC also, because of "by the book" implementation of analog frontend and software processing, which does not decimate raw data. If you use scope with accurate HF AC for long enough, DMMs gonna stay in the drawer for most of the time because one can change practices a bit. Maybe not even need to buy them so much and invest money in better scope instead.But if scope software has tricks in it you gonna be in for surprises when frequency does not divide well with decimation ratio or Sinc implementation is programmed so it causes large overshoot even with pure sine. In short - scope response is not simply predictable and depends heavily on input signal and simple dB corrections are not going to help - accuracy is permanently lost.So in general I do not see why fight the progress - it was time when single frame of video was blurry mess. Now at 4k it's way crisper than old film photos. Same with scopes. Highly accurate AC is going to be norm. Not coincidence that top of the line DMMs are starting to implement scope features and vice versa.

author: nctnico
author_rank: Super Contributor
timestamp: February 20, 2017, 10:44:35 pm
content: Quote from: rstofer on February 20, 2017, 09:30:52 pmMaybe not yet. On my previous scopes I have not used FFT much but since I have a scope on which FFT works well (quick & high frequency resolution) I find myself using FFT more and more. Though I have to admit I do a reasonable amount of projects involving (digital) signal processing.

author: bsas
author_rank: Regular Contributor
timestamp: February 21, 2017, 01:11:36 am
content: Thanks guys!But let me rephrase my requestI don't care about the FFT being super precise, since the audio applications I am thinking about are not super precise at all, I just need a visual aid about the harmonics that the circuit is amplifying, for example.My questions for DS1054Z owners is:1) If I need, for some specific problems, a very high quality FFT, is it possible to connect it via USB to a more complex data analysis software? Because if so, I can use the FFT in the DSO just for quick analysis and deep analysis I can dump the data to the computer and do it there.2) For everything else, do you recommend the DS1054Z or anyone here have a unit in mind at this price range that is better?Again, thanks all!

author: rstofer
author_rank: Super Contributor
timestamp: February 21, 2017, 03:31:02 am
content: Quote from: bsas on February 21, 2017, 01:11:36 amI have done offline FFT from data collected from external power measurement devices. It worked well but I had to practically go back to school to work it out. I don't have any idea how to sample with the DS1054Z. I know you need periodic samples and there are constraints on the sampling interval. Has only been an interest once, a long time ago.QuoteThose of us who like the DS1054Z don't believe there is anything less than twice as costly that even comes close. Those who hate the DS1054Z freely admit that their preferred device is at least $1000 and feel we should just pony up the bucks.I don't speak for anyone other than myself - I am entirely satisfied. When that is no longer true, I'll just buy something else. Remember, technology isn't standing still. No matter how good the DS1054Z is compared to the rest of the market, something better or cheaper will come along soon.If you want to spend a lot more money, there are better scopes on the market.

author: JPortici
author_rank: Super Contributor
timestamp: February 21, 2017, 06:17:43 am
content: Quote from: bsas on February 21, 2017, 01:11:36 amyes, you can. keep in mind that you still have 8 bit samples! which means that using more points won't give you better results unless tricks are used.. kinda..see:https://www.eevblog.com/forum/testgear/fft-spectrum-analysis-reviewed/msg920781/#msg920781Quotei don't.i probably fall into the "hate it" category, i have been very invested in the holy war in the past but now i simply don't care anymore.given that what those who recommend it say is true i don't recommend it because:1) measurements are done with data from screen memory, not from acquisition memory.. and screen memory data apperas to be just a decimation, which leaded to measurements inaccuracies (there are countless topics about it) one could argue that the numbers are still inside the accuracy spec but i have lost trust in them2) decoding is done by analyzing screen memory, which is bullshit.246 MPts (because we are using 4 channels) can contain a lot of packets! have to zoom in so that the decoder can do its job, have to manually scroll very slow or you will find you to be at the other end of the track in a single turn which leads to3) I find the UI to be painfully slow and unacceptable to be so, even when stopped. i'll give you that it has improved in recent updates to the point it's actually usable, when you don't have decoding and measurements on.there are other quirks but if i mentioned them i would really be nagging, they haven't been a real problem to me yet.if when stopped 1 and 2 weren't true because you're not acquiring new data, you can process the full memory.. it wouldn't be a showstopper.There are people who still use it despite this problems but i am not one of those. The scope doesn't work the way i want it to do (like what i use at work) so i'll change the scope.I am waiting for mid march to see how the new keysight is. then i'll unload the rigol to a friend and my bedroom lab will have either the new keysight or a siglent 1000xi can work with 2 (actually 3) channels, i do it all the time! not always straightforward but it can be done for what the op asksto the OP: you need more memory than sample rate/bandwidthQuoteit depends on what you actually need, a bit of everything or something specific, and if you are willing to spend 1-2 hundred more for it

author: djnz
author_rank: Regular Contributor
timestamp: February 21, 2017, 06:34:00 am
content: Afaik, Tektronix does measurements from acquisition memory, but Agilent / Keysight use screen data as well. I am sure the scope makers who don't use acq data but instead use screen data had their good reasons, I just sometimes wonder what they were and what sort of trade-offs went into that decision.

author: JPortici
author_rank: Super Contributor
timestamp: February 21, 2017, 06:53:54 am
content: yes i remember that thread (i should mention that i use picoscope/tektronix at work)i don't have direct experience with keysight but i am willing to try and see if its way of work will be okay for mei am sure that there is a way to use screen data without compromizing measurements too much. still, if i wanted to overlook the measurement point there is all the rest, decoding and UI, that are done differently on other brands.

author: MrW0lf
author_rank: Frequent Contributor
timestamp: February 21, 2017, 09:29:28 am
content: Quote from: djnz on February 21, 2017, 06:34:00 amThat's not entirely correct. They seem to use reduced size secondary buffer, but it is way larger than screen pixel count. Siglents follow similar logic (~70k on SDS1000X). Look this video:MSO-X 3000T vs Tektronix MDO3000Note that author arrives at somewhat incorrect conclusion that Agilent needs "higher sample rate" to get risetime measurement right. With 1GHz Agilent scope you need to be at about 1us/div, 5GSa/s to get ~12ns risetime correctly. Tek does similar at 200us/div in given video. According to my calculation MSO-X secondary buffer used for calculus is about 20k in size. Suppose it is done to mask lacking processing power. Rigol took same concept to the max with 0.3...0.6k buffer. So pick your poison. If you need measurements then full mem / large buffer scopes are in different class to Rigol/Agilent. If no need, other factors come to play.Edit: Looked up actual tests here:https://www.eevblog.com/forum/testgear/testing-dso-auto-measurements-accuracy-across-timebases/msg1091323/#msg1091323Indeed, Siglent SDS1102X+ gets numbers right at about 5us/div for similar risetime. So better than 1GHz Agilent in this regardConfusing stuff, gotta really understand your actual requirements before buying something...

author: Fungus
author_rank: Super Contributor
timestamp: February 21, 2017, 10:12:17 am
content: Quote from: rstofer on February 20, 2017, 08:51:21 pmThis. Wiggly lines and enough accuracy to know the power supply is OK.Absolute voltage measurement accuracy isn't very important. Oscilloscopes are for seeing the wiggles.

author: JPortici
author_rank: Super Contributor
timestamp: February 21, 2017, 11:57:56 am
content: and correlation in time domain between wiggles and events!

author: bsas
author_rank: Regular Contributor
timestamp: February 21, 2017, 03:17:02 pm
content: Thanks again for the advises!Another newbie question, sorry about that:- Is it possible to use the DS1054Z to plot a frequency response graph? For example, if I use a sweep frequency generator from 100Hz to 20kHz, can I setup the DSO to collect all and plot a historic graph? If not, is there any DSO under $1000 that can do that?Thanks!

author: Fungus
author_rank: Super Contributor
timestamp: February 21, 2017, 03:26:45 pm
content: Quote from: bsas on February 21, 2017, 03:17:02 pmNo, but you can use (eg.) an Analog Discovery for that:https://www.eevblog.com/forum/projects/analog-disovery-as-audio-analyzer/Plus: The Analog Discovery is a really useful toy when you start with digital electronics.They normally cost about $200.

author: Dan Moos
author_rank: Frequent Contributor
timestamp: February 21, 2017, 03:46:25 pm
content: Yes, you can do a frequency response graph (bode plot), but you are gonna have to do a little extra work. Dave did a video in fact.The gist is, you send the trigger pulse from your function gen to one channel on your scope, and the swept signal to another. If you set your scope's time base properly, you should have a single full sweep steady on screen. It will look like the bode plots you're used to seeing.OK, here's where the extra work comes. To find the -3db break point, do the math and set your cursor. To find the frequency at any point on the graph, it's gonna be easy or hard depending on whether you swept with log, or linear. Also, you need a function gen that can have the sweep set exactly. But it works.Sent from my E6830 using Tapatalk

author: rstofer
author_rank: Super Contributor
timestamp: February 21, 2017, 04:06:57 pm
content: Quote from: Fungus on February 21, 2017, 03:26:45 pmI wish I could have bought one for just $200 but, alas, us really senior citizens don't seem to get the student discounts (if such even exist for this product). Just another example of age discrimination (joking...mostly).One of the very neat features of the Analog Discovery is the Network tool. Sweep over some range of frequencies and get back amplitude and phase.If the Analog Discovery was the only piece of test equipment I had, I could still do a lot of electronics.http://store.digilentinc.com/analog-discovery-2-100msps-usb-oscilloscope-logic-analyzer-and-variable-power-supply/Attached is a Network sweep of a simple RC low pass filter using a 6800 Ohm resistor and a 10 nF capacitor. We expect the 3 dB point to be somewhere around 2350 Hz and it measures 2545 Hz.For those working on tuned circuits, this tool is outstanding.

author: MrW0lf
author_rank: Frequent Contributor
timestamp: February 21, 2017, 05:30:14 pm
content: Quote from: blueskull on February 21, 2017, 03:40:15 amBit OT but since you asked:https://www.picotech.com/oscilloscope/5000/flexible-resolution-oscilloscope5443A, 4ch, 64MB, 1GSa/sUS$2,055.00 / €1,745.00DC accuracy±50 mV to ±20 V ranges, >= 12-bit mode: ±0.25% typical @ 25°C (±1% of full scale max @ 20 to 30°C)±50 mV to ±20 V ranges, 8-bit mode: ±1% typical @ 25°C (±3% of full scale max @ 20 to 30°C)±10 mV and ±20 mV ranges: ±2% typical @ 25°C (±5% of full scale max @ 20 to 30°C)However must be aware of sampling rate limitations in 12-bit mode:any 1ch 500 MS/sany 2ch 250 MS/sany 3ch 125 MS/s4ch 125 MS/s(twice high in 8bit mode with ±1% typical @ 25°C)But not hackable, it's already 100MHzSo accurate scope is not some pipe dream, quite affordable if need this sort of thing. Tek/Agilent take about as much money for "regular" 8bit scopes.

author: nctnico
author_rank: Super Contributor
timestamp: February 21, 2017, 05:42:58 pm
content: Quote from: blueskull on February 21, 2017, 03:40:15 amThis is a contradiction since DC accuracy says nothing about AC accuracy and oscilloscopes are typically used for looking at AC (-ish) signals.

author: MrW0lf
author_rank: Frequent Contributor
timestamp: February 21, 2017, 05:56:39 pm
content: Quote from: nctnico on February 21, 2017, 05:42:58 pmPossibly this calls for some testing. Should be easy - can use high quality square. Look for overshoot at transitions. DC level can be confirmed on second channel + multimeter and compared to square tops. DC - peak = AC error. Or something similar. Sounds valid procedure? Sadly do not have 5000 but could test with latest 2000 soon.

author: JPortici
author_rank: Super Contributor
timestamp: February 21, 2017, 06:21:14 pm
content: Quote from: Dan Moos on February 21, 2017, 03:46:25 pmnot a bode plot, just frequency responce. you don't have any information on the phasei think that with a picoscope you could have both amplitude and phase (by using the math channels. you literally enter the function you want to plot)

author: bsas
author_rank: Regular Contributor
timestamp: February 21, 2017, 06:27:08 pm
content: For my current need which is audio applications (specifically guitar pedals and pre-amps) sounds like the "Analog Discovery 2" looks better for me.But it is $279 and I still need to use my computer.In the other hand, the Rigol DS1054Z is $399 (just $120 more) and it is a full independent DSO, and can be used with my computer too, right?My new questions are:1) How much more precise and better the Analog Discovery is compared to the 1054Z? And how much flexible it can be for all other applications that the 1054Z can provide me?2) I can see in the future having both units, but for a beginner like me that I will be learning basic components like opamps or basic transistor circuits, which on will be better to start with?Thanks!

author: JPortici
author_rank: Super Contributor
timestamp: February 21, 2017, 06:44:42 pm
content: Quote from: bsas on February 21, 2017, 06:27:08 pma lot. you don't care about bandwidth. you care about resolution and noise (more bandwidth <-> more noise)also you have a signal generator, pattern generator, ...I agree that it's annoying to use it with a computer but while you are designing/programming you probably have your computer besides you anywayQuotei think the AD is still better because you have more tools like signal generator and you still don't need to care about the bandwidth.If the choice has to be between these two and you don't have other equipment i'd be inclined to say go with the AD

author: bsas
author_rank: Regular Contributor
timestamp: February 21, 2017, 07:19:25 pm
content: What is the difference between the analog discovery 1 and 2?

author: rstofer
author_rank: Super Contributor
timestamp: February 21, 2017, 07:40:00 pm
content: Quote from: bsas on February 21, 2017, 06:27:08 pmThe AD has a 14 bit A/D converter versus 8 bits for most scopes including the DS1054Z. That's a HUGE difference in resolution! The DS1054Z will have a higher bandwidth and 4 channels but, in my view, 4 channels are better used in the digital domain and the AD has 16 bits of digital IO. That means I get the full SPI transaction with 12 channels left over versus using all 4 channels of the DS1054Z.The AD is perfect at the frequencies most used with op amps and transistor circuits. I was fooling around with some transistor logic circuits the other day using the digital IO but then I turned around and built up a properly biased Class A transistor amplifier which I looked at with the Network tool of the AD. You just can't do that with the DS1054Z.I would highly recommend starting with the AD because it is a pretty complete electronics lab in a hand held box. In my work area, I have several computer workstations. No reason, really, but I'm never more than 3' away from a computer. I haven't done it but I could certainly justify using LTspice to model a circuit and the AD to see how it really works.Having the two arbitrary waveform generators, something the DS1054Z doesn't have, is perfect for providing signals to breadboard circuits. Usually the waveform will be a simple sine wave but there are square, ramps, triangle and a few others plus you can invent your own.I could see a college student buying one of these gadgets and using it throughout the EE program. Add in a laptop with LTspice and Maxma (wxMaxima) and I think you have everything necessary to do the work. OK, I would add Eclipse (the IDE) and GNU Fortran but that's just me...I think the BNC adapter board is a necessary add-on:http://store.digilentinc.com/bnc-adapter-board-for-the-analog-discovery/As are two scope probes (maybe 4 if you want to use probes to inject signals):http://store.digilentinc.com/bnc-oscilloscope-x1-x10-probes-pair/Those can probably wait because, more often than not, I just use pin headers on the solderless breadboard and connect the signals with the flyleads on the header that comes with the AD.I like the gadget a lot! Nevertheless, it isn't my money and it isn't my decision. I have both the AD and a DS1054Z plus there is a Tek 485 under the table. I bought the AD years before I bought the DS1054Z and, to be honest, I only bought the scope because I wanted to see how they worked. I could very well have just used the AD for the lower frequency stuff and the 485 for everything else - which is exactly what I did for quite a long time.Download the software and play around with the Demo device. Read the specs, see the tutorials, learn all you can about the gadget before you spend your money. All in, the AD plus attachments will cost just about as much as the DS1054Z. And you might consider the box of analog parts that go with the ADhttp://store.digilentinc.com/analog-parts-kit-by-analog-devices-companion-parts-kit-for-the-analog-discovery/

author: rstofer
author_rank: Super Contributor
timestamp: February 21, 2017, 07:44:23 pm
content: Quote from: bsas on February 21, 2017, 07:19:25 pmThe 2 version has adjustable supplies and the ability to provide more power by adding a wall wart among other things. For details, see here:https://blog.digilentinc.com/a-comparison-of-the-analog-discovery-and-analog-discovery-2/

author: mtdoc
author_rank: Super Contributor
timestamp: February 21, 2017, 07:47:06 pm
content: Quote from: bsas on February 21, 2017, 07:19:25 pmDifferent case.Adjustable 0-5V power supply on the 2 versus fixed 5 V on the one - with the added ability on the 2 to power it external from the USB port to put out up to 2.1Watt per channel instead of 250mW.Other than the power supply - no differences in the hardware or performance.

author: MrW0lf
author_rank: Frequent Contributor
timestamp: February 21, 2017, 07:50:01 pm
content: Quote from: JPortici on February 21, 2017, 06:21:14 pmSomeone made nice app for that (phase and amp), but works with internal function gen, so limited by its max frequency.https://bitbucket.org/hexamer/fra4picoscope/wiki/HomeWithout phase could do sweep with (external) gen using FFT persistence mode.Currently not sure if could do phase and amplitude plot with just math channels, would be interesting puzzle to solve sometime.Quote from: bsas on February 21, 2017, 06:27:08 pmAD2:https://reference.digilentinc.com/reference/instrumentation/analog-discovery-2/reference-manual?redirect=1#features_and_performancesResolution: 14-bitAbsolute Resolution(scale ?0.5V/div9)): 0.32mVAbsolute Resolution(scale?1V/div10)): 3.58mVAccuracy (scale?0.5V/div, VinCM = 0V): ±10mV±0.5%Accuracy (scale?1V/div, VinCM = 0V): ±100mV±0.5%If try calculate for 5Vpp range:(0.01 / 5 * 100) + 0.5 = +-0.7%DS1000Z:http://beyondmeasure.rigoltech.com/acton/attachment/1579/f-04cf/0/-/-/-/-/file.pdfDC GainAccuracy<10 mV: ±4% full scale>=10 mV: ±3% full scaleSo in different ballpark.

author: Fungus
author_rank: Super Contributor
timestamp: February 21, 2017, 08:04:55 pm
content: Quote from: bsas on February 21, 2017, 06:27:08 pmIn your frequency ranges (up to 100kHz)? Alot. The 14 bit DAC will make ahugedifference in FFTs, etc.Plus the AD works as a signal generator and you can easily automate things like frequency response testing using it.Quote from: bsas on February 21, 2017, 06:27:08 pmAnalog Discovery.

author: DimitriP
author_rank: Super Contributor
timestamp: February 21, 2017, 08:09:29 pm
content: Quote...and while you are deciding .... you can check outhttp://audio.rightmark.org/products/rmaa.shtmlandhttp://www.daqarta.com/

author: bsas
author_rank: Regular Contributor
timestamp: February 21, 2017, 08:20:21 pm
content: Awesome feedback guys, thanks!I am decided on the AD2. Just waiting for next paycheck in 2 weeksQuick last question about it: what is the difference between "WaveForms" and "WaveForms 2015"?

author: rstofer
author_rank: Super Contributor
timestamp: February 21, 2017, 09:27:14 pm
content: Quote from: bsas on February 21, 2017, 08:20:21 pmWaveForms 2015 is the newest version and the one I am using. It has a lot more capability than WaveForms. However, there are a number of college programs built around WaveForms so I suspect it is still available for those specific users.I think you'll like the AD. Breadboard some circuits and learn to use the device. Something as simple as a low pass filter takes on a real life when you can get the Bode' plot with very little effort. All of a sudden, the equations make sense!The lowly transistor Class A amplifier with the emitter bias resistor will come alive with the Network gadget or even just the dual channel scope watching input voltage and output voltage. You can expand the idea by using an op amp as a x10 inverting amplifier (for example) and plotting input/output. The equations for gain vs feedback resistors rock!Don't forget, you can use the Digilent Adept library to create custom instrumentshttps://reference.digilentinc.com/_media/waveforms_sdk_reference_manual.pdfThere is a lot of educational material related to AD on the Digilent site.

author: Fungus
author_rank: Super Contributor
timestamp: February 21, 2017, 09:37:29 pm
content: Quote from: MrW0lf on February 21, 2017, 05:30:14 pmNot 100MHz with 4 channels on.

author: MrW0lf
author_rank: Frequent Contributor
timestamp: February 21, 2017, 10:16:59 pm
content: Quote from: Fungus on February 21, 2017, 09:37:29 pmMight just barely make it in 8 bit mode, ±50 mV to ±20 V range if room is typically at 25C

author: kcbrown
author_rank: Frequent Contributor
timestamp: February 22, 2017, 12:22:12 am
content: Quote from: MrW0lf on February 21, 2017, 10:16:59 pmWhy aren't other 8 bit scopes able to achieve the same thing?

author: nctnico
author_rank: Super Contributor
timestamp: February 22, 2017, 12:46:51 am
content: Quote from: kcbrown on February 22, 2017, 12:22:12 amRegular oscilloscopes have a much larger range and allow higher input voltages. This translates to a less accurate input divider.BTW note that the jitter spec on the Picoscope 5000 series is severely inadequate for the high resolutions/samplerate they specify. Seewww.linear.com/docs/25374

author: kcbrown
author_rank: Frequent Contributor
timestamp: February 22, 2017, 03:06:53 am
content: Quote from: nctnico on February 22, 2017, 12:46:51 amI don't follow. That would make sense if you were limited to a fixed voltage range, but if that were the case, then with an 8 bit ADC you wouldn't be able to see signals down to 2mV with a simultaneous maximum of 30VRMS on the input. The smallest voltage change you'd be able to see in that case would be about 330mV.If you'renotlimited to a fixed voltage range, as seems to be the case (indeed, when you're playing with the vertical scale knob on a DS1054Z, you can hear a relay switch over when transitioning between 5V/div and 2V/div) then you'd be able to get 8 bits worth of resolution in whatever range you're actually recording, as defined by how the scope maps the vertical settings to the internal gain and offset. Given that, why is the Picoscope better?

author: Fungus
author_rank: Super Contributor
timestamp: February 22, 2017, 08:16:55 am
content: Quote from: nctnico on February 22, 2017, 12:46:51 amI wonder if Wolfie's read that.

author: Fungus
author_rank: Super Contributor
timestamp: February 22, 2017, 08:19:15 am
content: Quote from: kcbrown on February 22, 2017, 03:06:53 amBecause that particular model costs $2000.(ie. they can spend a lot more on the amplifiers, etc., than a $400 Rigol which also has to include a screen, ethernet, USB and control knobs in the $400 price)

author: MrW0lf
author_rank: Frequent Contributor
timestamp: February 22, 2017, 09:17:02 am
content: Quote from: kcbrown on February 22, 2017, 12:22:12 amWild guess - since it is 16bit scope in some modes, they have put much higher effort into overall system design compared to regular 8bit scope, making 8bit mode operating at about theoretical max. There are some FFTs tests done that show that overall implementation quality is rather good:https://www.eevblog.com/forum/testgear/fft-spectrum-analysis-reviewed/Some random outtake from here:https://www.eevblog.com/forum/testgear/fft-spectrum-analysis-reviewed/msg921288/#msg921288"I just did some captures with a couple of PicoScopes and also a LeCroy WaveAce 102 in all cases the input was a 1.8V pk-pk 20kHz low distortion sine wave. SFDR figures:LeCroy WaveAce 102 50dB (approx)PicoScope 5244B 68dB (8 bit mode)PicoScope 5244B 78dB (16 bit mode)PicoScope 4262 93dB (16 bit)"Quote from: nctnico on February 22, 2017, 12:46:51 amJust to be clear - what exact specs you are talking about? After little homework found these:AD2: no specTek TBS2000: Time base accuracy ±25 ppm over any ?1 ms interval; Sample jitter: no specDS1000Z: Timebase Accuracy: <=±25 ppm (typical); Clock Drift <=±5 ppm/year; Sample jitter: no specPico 5443A: Initial timebase accuracy: ±2 ppm; Timebase drift: ±1 ppm/year; Sample jitter: 3 ps RMS, typicalAre we on the same page with numbers?Also, 1% accuracy talk was aboutDC accuracy, what it has to do with timebase accuracy at all?From FFT tests its evident that 5000 is not strictly optimized 16bit scope indeed, but on the other hand it's excellent 8bit scope. Probably 12bit mode lands squarely in the middle. If sole purpose is ultra accurate, low frequency 16bit work, there are specialized scopes for that.So overall dunno if there is really anything to whine about. In my practice they usually work better than spec. So expecting delivery of 2408B to finally work on some projects, not debugging measurement hardware all the time

author: Fungus
author_rank: Super Contributor
timestamp: February 22, 2017, 11:26:02 am
content: Quote from: MrW0lf on February 22, 2017, 09:17:02 amHaving a $2000 budget probably helped, too.

author: MrW0lf
author_rank: Frequent Contributor
timestamp: February 22, 2017, 12:06:22 pm
content: Quote from: Fungus on February 22, 2017, 11:26:02 amWell quality costs. Comparably it's not more expensive than AD2 chosen by OP. Cannot imagine what Tek would charge for such scopes if they sell some silly probe adapters for $400 per pc

author: rstofer
author_rank: Super Contributor
timestamp: February 22, 2017, 03:57:17 pm
content: Quote from: bsas on February 21, 2017, 08:20:21 pmSpend the time to review the specs for input voltages, power supply capability, etc. Direct input is limited to +- 25V - clearly enough for a lot of electronics projects but probably not enough for some circuits.You can use x10 scope probes and probably should. You would need the BNC adapter board. I don't use mine unless I am getting out of the realm of low frequency and low voltages (I tend to work at 5V or less).Read the note in section 2 here:https://reference.digilentinc.com/reference/instrumentation/analog-discovery-2/reference-manual?redirect=1It takes a bit of reading to digest what it says. Read is several times! Basically, the AD is grounded through the USB connection unless a USB isolator is used. There needs to be a common ground between the circuit under test and the AD. So, when I use a separate wall wart for a supply, it better be floating because I am going to create a ground at the project (usually on the - side of the wall wart) and connect one of the AD black ground wires to that point. It isn't enough to just probe the circuit with the two scope leads (differential input like orange and orange/white or blue and blue/white), you need to get a black wire in there somewhere.The easy way to think about this is that the blue/white or orange/white scope input wires should be connected to the circuit ground as should one of the adjacent black wires. Look at the BNC adapter schematic to figure out how Digilent handles SGND - pins 25, 28 and 30.https://reference.digilentinc.com/_media/analog_discovery_bnc_adapter_board:discoverybnc_sch.pdfIt isn't nearly as big a bother as the note implies and it is made a whole lot easier if you are using the AD power supplies but I have to believe that the BNC adapter is the right way to use the thing as a scope. Then you can use conventional scope probes and all the SGND stuff is taken care of.If you really need differential inputs, no problem. Just make sure that the black wire connects to circuit ground.After a few moments of thought, this all becomes much ado about nothing. But there are circuits where the voltages are out of range or the circuit ground can't be connected to earth ground. These circuits need a lot more thought.This stuff all applies to regular scopes as well. Dave has made a video describing how to avoid blowing up a scope. It all has to do with the ground connection! That thing can be a real issue.

author: bsas
author_rank: Regular Contributor
timestamp: February 22, 2017, 06:44:13 pm
content: Quote from: rstofer on February 22, 2017, 03:57:17 pmThanks for the advise! My goal is to work on guitar pedals, so, basically 9V DC low current (less then 100mA) circuits. So, the limit looks more then enough for me.Even so, I will buy the "PRO" bundle that comes with the 1x and the 10x probes, and the BNC adapter. I was planning that anyway.Also, I will buy the 9V breadboard USB adapter from Digilent (PowerBRICKS). The benefit is that it is more then enough power for my circuits (9V 130mA if I am not wrong) and they will share common ground since both the power supply and the AD will be connected to my computer USB bus.

author: rstofer
author_rank: Super Contributor
timestamp: February 22, 2017, 08:04:15 pm
content: Quote from: bsas on February 22, 2017, 06:44:13 pmOutstanding approach! I haven't tried the PowerBRICKS but I plan to order a set in the near future. They seem to be quite handy for breadboarding.BTW, I don't connect much of anything directly to my Surface Book. I have a powered USB hub with 7 USB ports and 3 charging ports. Like this:https://www.amazon.com/gp/product/B00VDVCQ84/ref=oh_aui_search_detailpage?ie=UTF8&psc=1I should probably add a USB Isolator between the Book and the Hub but they get very pricey when considering USB 2.0. USB 1.1 would be very slow in comparison.