Analog Disovery as Audio Analyzer - Page 1
Forum section: electronics / projects

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 10, 2015, 05:30:03 pm
content: First off, I know a lot of people on this board got some some misconception that audio is not engineering and everything sounds the same due to many of Dave's comments on the subject. If you feel this way, feel free to skip this thread.Anyway, there is a lot of interesting engineering associated with audio. Personally I wanted to do some measurements on a couple of amplifiers using the software supplied with my Digilent Analog Discovery unit, but I really find it somewhat limited for this purpose, sure it will do most measurements, but it's very time consuming and the supplied software is a little buggy, not always showing the truth.I am aware using a PC soundcard is an option (even up to 24 bits/low bandwidth) but I find the sound card option being somewhat limited as you don't know what level you are testing at and often very fiddly to configure.The Analog Discovery is"only"14 bits, so limited on the dynamic range, but on the positive side it's got up to ~10MHz+ bandwidth. Anyway, as I got some experience with the API from other projects, I have decided to write some dedicated software for this purpose.Primary purpose is amplifier measurements.

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 10, 2015, 05:31:17 pm
content: Here the screen to measure THD+N vs frequency at a specific power/output level:Note, minimum THD+N is about 0.01% due to limitations in the Discovery unit. But unlikely anyone can identify distortion that low anyway, especially considering even the best speakers distort 0.1% +++ in an anechoic chamber without any reverberations. Living room conditions is unlikely to every be below 1% distortion even a low levels.More important is the ability to analyze the harmonics causing the distortion, generally even harmonics are considered much more pleasant than odd harmonics.

author: Lightages
author_rank: Unknown
timestamp: December 10, 2015, 05:38:08 pm
content: Who said that audio electronics is not an engineering topic? It is very much so! I think you are mistaking the disdain here for woo woo claims in the audiphool realm as a disdain for all subjects about audio. Not so.Looks like you have a winner there with that set up. The Analog Discovery is a great bit of kit and it is very capable of doing many things for a cheap price. I could only dream of having those capabilities when I was younger.What amplifier are you measuring in that image?

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 10, 2015, 05:48:21 pm
content: Quote from: Lightages on December 10, 2015, 05:38:08 pmThanks, I agree, unfortunately some seem to lack the insight to discern the difference e.g. I've seen using a film capacitor instead of a ceramic as coupling being called audiophoolery, instead of common sense.Anyway, thanks for the positive comment, much appreciated.This is a measurement of a tiny little class D amplifier based on a Tripath chip, I will post more details.

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 10, 2015, 05:51:17 pm
content: Here measuring the output level vs % THD+N, useful to know how many watts you can expect from an amplifier with a specific load:

author: c4757p
author_rank: Super Contributor
timestamp: December 10, 2015, 05:56:40 pm
content: Quote from: Lightages on December 10, 2015, 05:38:08 pmQuote from: jaxbird on December 10, 2015, 05:48:21 pmI second this. It's pretty hard to bring up any discussion of audio quality and design without the "everything is bullshit" brigade coming out. It's a cheap and easy way for people with a limited knowledge of engineering to look smart to their peers.Subscribed, not so much for audio as for Clever Use of Analog Discovery. It's a neat little doohickey

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 10, 2015, 06:22:32 pm
content: Quote from: c4757p on December 10, 2015, 05:56:40 pmThanks, appreciate your contribution, hope it will help define the border between actual engineering and foolery, it's really a difficult topic as often some foolery claims are indeed somewhat true at high frequencies, but completely negligible below 20kHz.

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 10, 2015, 06:31:51 pm
content: This is the board I'm testing here: (it's a small class D amplifier)This is the test setup:

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 10, 2015, 06:53:24 pm
content: Short video demonstrating the functionality implemented so far, it's still work in progress:

author: mtdoc
author_rank: Super Contributor
timestamp: December 10, 2015, 06:54:22 pm
content: Very cool. Any chance you'll be releasing your "Audio Analyzer Suite"?I just recently upgraded to the Waveforms 2015 software (now available for Linux, MacOS and ARM!) . I like the changes they've made. Your applications seems like a very useful addition.

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 10, 2015, 07:06:36 pm
content: Quote from: mtdoc on December 10, 2015, 06:54:22 pmSure, as soon as I am somewhat happy with it. This is just a very early version. I do want to add a small plug in PCB design. The Discovery unit max input is +/- 25V, that is a bit limited for testing larger amplifiers, so adding a small board with a programmable divider is needed. Plus perhaps some phono jacks or just screw terminals and perhaps some added protection to make sure the unit is never damaged.I haven't tried the Waveforms 2015, my current version is 2.7.5 and it's got some bugs, not so obvious ones, but I've noticed it doesn't always display the spectrums correctly depending on settings.My goal is to make it really easy to do audio measurements.

author: miguelvp
author_rank: Super Contributor
timestamp: December 11, 2015, 04:28:26 am
content: Nice, Also I'm going to upgrade to Waveforms 2015 since I saw the new Analog Digital Discovery 2 and had a link to the updated software, but have not had a chance.

author: Fungus
author_rank: Super Contributor
timestamp: December 11, 2015, 06:53:37 am
content: Quote from: c4757p on December 10, 2015, 05:56:40 pmOK, I'm here now. What audio bullshit are we discussing today? My $100 system sounds fine to me.

author: moffy
author_rank: Super Contributor
timestamp: December 11, 2015, 07:07:52 am
content: Really nice plots and board. Have you tried THD+N vs frequency for your D Class amp yet? That would be interesting. Also even though it is 14 bits can't you oversample to increase your resolution?

author: rjeberhardt
author_rank: Regular Contributor
timestamp: December 11, 2015, 11:49:16 am
content: Can you do intermodulation distortion with that kit? I've often thought that intermodulation is more significant than THD especially when you see how THD rises at higher frequencies. Music is almost never just a single tone.Russell.

author: RobK_NL
author_rank: Frequent Contributor
timestamp: December 11, 2015, 02:45:46 pm
content: Quote from: jaxbird on December 10, 2015, 06:31:51 pmIt would be interesting to see if you can actually measure any difference between the two channels, seeing as how you've got a broken filter inductor on channel 2

author: c4757p
author_rank: Super Contributor
timestamp: December 11, 2015, 02:46:48 pm
content: Quote from: rjeberhardt on December 11, 2015, 11:49:16 amThat should be possible, in theory.

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 11, 2015, 06:17:27 pm
content: Quote from: rjeberhardt on December 11, 2015, 11:49:16 amQuote from: c4757p on December 11, 2015, 02:46:48 pmIndeed, should be doable, and a feature I surely will add. The Discovery unit includes a dual 100Msps DAC and the API exposes functions to produce regular waves (sine, square, triangle plus modulation) but not multitone directly, however it is possible to pass a 4k sample buffer and have it played back at a specified sample rate, so the challenge would be producing a continuous/repeating buffer with 2 tones without glitches. Should be doable with the common 19+20kHz test signal.Then just display the spectrum from e.g. 20Hz to 30kHz and it should give a good view of the intermodulation distortion performance.Another option would be to just combine the two waveform channel outputs with some resistors to form the dual tone test signal. (this I have tried already and it works fine)If anyone got a good formula for creating a continuous/glitch free buffer with 2 or more frequencies, I'd be grateful as it would save some time

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 11, 2015, 06:28:33 pm
content: Quote from: miguelvp on December 11, 2015, 04:28:26 amThanks, Just installed the Waveforms 2015 version 3.1.5, the UX is better and it's easier to access/switch between instruments. Have not done a lot of testing, but it appears they have actually removed some features, or maybe I just can't find them.Really I just wanted to know if they made any API changes, but everything I've written is compatible, so it seems no API changes, the API already had the features needed for a variable output PSU as now available in Discovery V2.

author: diyaudio
author_rank: Frequent Contributor
timestamp: December 11, 2015, 08:08:26 pm
content: Quote from: jaxbird on December 10, 2015, 05:30:03 pmmy alias gets me into shit every time with some members around here, yet i have no association with audio only.

author: rjeberhardt
author_rank: Regular Contributor
timestamp: December 12, 2015, 08:02:51 am
content: Quote from: jaxbird on December 11, 2015, 06:17:27 pmThanks. Could give some interesting results.Russell.

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 12, 2015, 10:10:17 pm
content: Spent some hours today adding new features, first frequency response, pretty straight forward. Will show scale either referenced to input signal or referenced at 1kHz level.

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 12, 2015, 10:14:44 pm
content: Also been playing around with the intermodulation distortion feature, this should give a good view of the IMD performance:0 dB is the level of the two test tones.

author: fivefish
author_rank: Frequent Contributor
timestamp: December 12, 2015, 10:52:53 pm
content: jaxbird, that is awesome. If you keep this up, and release this software I think I will be buying an Analog Discovery and then send some $$$ your way.Please make this a "poor man's AP setup"

author: fpliuzzi
author_rank: Regular Contributor
timestamp: December 13, 2015, 12:21:06 am
content: Awesome is a good word for your audio analyzer suite. I was perfectly happy with the capabilities of my Analog Discovery, but now I'm really glad that I own one (although my trusty HP334A is looking a little nervous that it could be departing my main test bench soon to free up some much needed space).Also, a quick thought about your IMD feature. If you see some value in this idea, could the amplitude of the two test tones be made independently adjustable so that you could, for example, test a vintage piece of audio gear using the older SMPTE standard (frequencies of 60Hz and 7KHz, mixed in a 4:1 ratio) if that was desired?That could make an interesting way to compare the test results of the various IMD standards by supplying the appropriate test frequencies and amplitude ratios.I tip my hat to you... keep up the excellent work.

author: timofonic
author_rank: Frequent Contributor
timestamp: December 13, 2015, 01:19:16 am
content: What about augmenting Sigrok capabilities based on your choice and research? It would be amazing to have these features on this multiplatform and ever expanding software developed by volunteers!

author: rjeberhardt
author_rank: Regular Contributor
timestamp: December 13, 2015, 03:04:11 pm
content: Excellent! I must put an Analog Discovery on my Christmas present list.Russell.

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 14, 2015, 04:46:58 pm
content: Quote from: rjeberhardt on December 13, 2015, 03:04:11 pmQuote from: fivefish on December 12, 2015, 10:52:53 pmThanks, much appreciate the positive comments.Quote from: timofonic on December 13, 2015, 01:19:16 amMaybe at some point, but tbh, I've never had a positive experience contributing to existing open projects.

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 14, 2015, 04:55:42 pm
content: Quote from: fpliuzzi on December 13, 2015, 12:21:06 amThanks, the HP334A is a nice instrument, but it does require a bit a patience to adjust it correctly.I've made some minor changes that gives more flexibility on the IMD testing, the level of the 2nd tone is now set as a percentage of the level of the 1st tone. That will allow the tests you described.Always open to suggestions.

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 14, 2015, 05:10:27 pm
content: Also added the Output Impedance feature. It requires 2 resistors, just use some within the range of realistic speaker impedance for best results. Could do open vs load, but I feel the two resistor method is better.Here from measuring the same little class D board, using a log value scale because of the rise at high frequencies, but lin/log is optional.

author: bson
author_rank: Unknown
timestamp: December 14, 2015, 07:03:33 pm
content: I'd suggest an LTspice experiment with a simple op-amp driving an 8ohm resistive load; measure the THD+N. Then replace the resistor with an inductor and parasitic resistor of say 0.1ohm that gives you |Z|=8ohm at 10kHz. Check the THD+N. Then repeat at say 2ohm and 200ohm. This will teach you resistive loads are useless for design purposes and their only use with audio amplifiers is to generate fantastic-looking numbers for marketing collateral. (Other than smoke testing of course, without risking destruction of real drivers.)

author: fpliuzzi
author_rank: Regular Contributor
timestamp: December 14, 2015, 07:08:12 pm
content: jaxbird, your change to the IMD test instrument allows great flexibility in setting up the test parameters for the various present, and possibly some future IMD standards (better than just having a couple of presets for the most commonly used ones). It also allows for experimentation, which is always interesting. Thank you for implementing this feature.

author: fivefish
author_rank: Frequent Contributor
timestamp: December 14, 2015, 07:31:55 pm
content: jaxbird: Are you using Analog Discover or Analog Discovery 2?Side-Topic: What's the advantage of AD2 vs. original AD? Will Waveforms 2015 run on the original AD?I'm deciding what kind of AD to get to run jaxbird's software

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 15, 2015, 06:26:25 am
content: Quote from: bson on December 14, 2015, 07:03:33 pmIn essence what you are saying is that there is no point in standardized testing of amplifiers as using resistive loads are not equal to speaker loads.I cannot say I agree, surely many valuable performance details are revealed using resistive loads. Based on these results it's even possible to make good predictions about the performance when combined with a specific speaker simply by looking at the speaker's impedance behavior, frequency response/dispersion pattern, sensitivity etc. And by using standardized tests with standardized loads the results are comparable.

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 15, 2015, 06:28:01 am
content: Quote from: fpliuzzi on December 14, 2015, 07:08:12 pmThanks, it was a great suggestion. I will probably still add some general purpose spectrum analyzer screen with optional tone generator for more experimentation, but I like to have purpose specific tools for most standard tests.Maybe at some point even add a scope/tone gen with the option to view signal with the fundamental notched out similar to what you'd get from many of the traditional distortion analyzers.

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 15, 2015, 06:33:17 am
content: Quote from: fivefish on December 14, 2015, 07:31:55 pmMine is the v1, but even v1 got different hardware versions, mine is revision C or D I think. But they are all compatible afaik, even with version 2. From a quick look I believe the major differences is that v2 got more analog bandwidth (30MHz+ vs 15MHz+) and a variable output power supply (v1 is fixed +/-5V, 50mA limited). Waveforms 2015 runs just fine with my v1.I'd get a v2 if I need to get another one.If you get one you might be interested in this other project I did based on the Analog Discovery:https://www.eevblog.com/forum/projects/impedance-analyzer-build-and-experiments/135/

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 15, 2015, 07:13:39 am
content: And just for fun, why not... this is a single ended mono amplifier, need two for stereo, capable of something like 5-10W output. Analog Discovery for scale and my little class D test amplifier board next to it.I don't actually use these amplifiers as they don't produce much watt and I don't have any appropriate high efficiency/gentle impedance speakers for them, but to be honest, their coolness factor is hard to beat, so they do have a prominent display in my living room. I originally got them quite cheap as they were not working well, so I've done some work and modifications to get them into good working order. It was during this repair work I thought I needed something to easily measure and diagnose an amplifier resulting in the software I'm now doing for the Analog Discovery.

author: mtdoc
author_rank: Super Contributor
timestamp: December 15, 2015, 08:45:36 am
content: Quote from: jaxbird on December 15, 2015, 06:33:17 amI suspect there is no significant difference between hardware versions. Scope bandwidth on V2 is advertised as 20 MHz with BNC adapter on the NI website and 30MHz on Digilent's site. The spectral characteristics diagram for V2 onit's wiki pageis the exact same as the one onpage 16 of the V1 technical reference manual. In fact the V2 wiki looks to just be a web adapted version of this manual. Digilent made a silly marketing decision with V1 to market the scope as 5 MHz because they "did not want to confuse students" who might not understand the concept of a -3dB bandwidth. You can read this on page 16 of the technical reference manual.I think once Digilent was bought by National Instrument, NI decided to put the AD in a new case and call it V2 with a more accurate bandwidth advertised. (though I question the 30 MHz bandwidth given the 100 MSPS for both scopes ADC, regardless of the -3dB measurement)I'll be happy to be proven wrong but I think the only additional hardware of note is the addition of external power input to augment the power supply - the least useful feature of the AD IMO. Basically I think V1 = V2 just without the fancy case, ext power input and marketing fluff.

author: fivefish
author_rank: Frequent Contributor
timestamp: December 15, 2015, 09:02:26 am
content: jaxbird, big kudos to you on this project.More questions: I assume the software will work with line level signals?How about what if I need to measure DUT gear with balanced input/output, I'm thinking I'll need to convert the signals from the AD to balanced and vice versa before feeding it to the DUT gear. Have some kind of breakout box with the balanced converter circuits before the AD box? will that screw up the readings?-- how about a "normalize" function, say measuring freq response, have the software automatically normalize the resulting curve to 0dB reference.

author: bson
author_rank: Unknown
timestamp: December 15, 2015, 09:36:58 am
content: Quote from: jaxbird on December 15, 2015, 06:26:25 amYes. Did you follow the suggestion to run a simulation with different kinds of loads?

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 18, 2015, 05:53:18 am
content: Quote from: fivefish on December 15, 2015, 09:02:26 amThe Discovery got 2 differential inputs accepting up to +/-25V with 2 attenuation levels, to measure larger amplifiers more attenuation is needed.For balanced signals, the differential inputs are fine, but for balanced output it would be best to add something like this:You'd just need to check theRef 1kHzbox to set reference level at 1kHz level, otherwise it displays the voltage gain referenced to input level.

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 18, 2015, 06:14:22 am
content: Quote from: mtdoc on December 15, 2015, 08:45:36 amI wasn't even aware that NI had bought Digilent, but I guess they fit in nicely in the low end compared to Ni's more high end products.I think you are right, they could have made some minor adjustments to the front end (just component values as the AD8066 should have enough bandwidth).The added power supply features are probably worth the extra $20. I just had a look at microchipdirect.com, they used to sell the original for just over $200 to non students, but now it's the same $259 as everywhere else.

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 18, 2015, 07:48:12 am
content: Quote from: bson on December 15, 2015, 09:36:58 amYou seem persistent, so let's do a little experiment, instead of a simulation, to find out how much difference there really is and what it looks like.Here is a comparison between using a typical small 2 way speaker with an impedance between 5 Ohm and 20 Ohm, compared to a 6 Ohm resistive load.2 Way speaker's impedance for reference:6 Ohm load resistor's impedance: (not very exciting)Distortion measurement with Speaker load:Distortion measurement with Resistive load:The only difference here is that the amplifiers distortion is actually overalllowerwith the speaker loadEspecially at the frequencies where the speakers impedance is higher.

author: timofonic
author_rank: Frequent Contributor
timestamp: December 18, 2015, 08:30:32 pm
content: 269USD? I thought it would cost 100USD as much...Is his really interesting?

author: miguelvp
author_rank: Super Contributor
timestamp: December 18, 2015, 08:34:58 pm
content: There is also the NI edition for students only:http://sine.ni.com/nips/cds/view/p/lang/en/nid/213328It does come with Multisim Student Edition as well.

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 19, 2015, 12:26:00 am
content: Quote from: timofonic on December 18, 2015, 08:30:32 pmI agree, it's a good chunk of money, IMO for the features it's worth the cost, it's got 14 bit resolution on the 100Msps ADCs, DACs, plus 100Msps 16ch logic in/out. It's like a little Swiss army knife, with some patience it will do most jobs, but it can not compete with a dedicated instrument at any specific task.And of course, like any instrument, it's only worth it if you got a use for it, like e.g. you don't already have an arbitrary function gen or you don't already have a logic analyzer/generator or high res scope, low frequency spectrum analyzer or network analyzer etc.If it's just another toy that will start collecting dust after a week, then it's probably not worth the money

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 19, 2015, 12:29:45 am
content: Last feature for now, I think, input impedance measurements:Then I just need to clean it up, do a bit of testing and bug bashing.

author: fivefish
author_rank: Frequent Contributor
timestamp: December 19, 2015, 02:41:14 am
content: Looking forward to the release of this software jaxbird. Then I'll get an AD.Excellent work.Hey, how hard is it to do a "normalize"... i.e. the software takes a base reading, normalize it to flat response, then put the DUT, and let the software do it's thing (relative to the normalized base reading)?

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 23, 2015, 02:19:04 pm
content: Quote from: fivefish on December 19, 2015, 02:41:14 amThanks, but you should only invest in the Analog Discovery if you really feel you have a use for it, no obligationsI'm putting a lid on new features until a release is available, after that I'll start tracking bugs and feature requests.I've been preparing the software for distribution, primarily to make it easy to distribute and update, so I've gone with a web deployment strategy with update check on startup. It will still run fine offline, but if online and there is a new version available on startup it will suggest to update. Not that I expect it to be full of bugs, but I'm sure there will be many updates initially so easy updating is fairly high priority.Also it needs a bit of explanation on how to configure connections for the various measurements, some measurements require various shunt resistors. So I'm compiling a document for reference and perhaps a video.Anyway, I expect to have an install ready within the next couple of days.

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 24, 2015, 09:53:32 am
content: Made a couple of minor changes:The power vs THD+N now includes the input level. It's nice to know what input level is required e.g. when clipping occurs. I'm considering adding a scope view as it's nice to know the balance, as in, if one rail is clipping prematurely.Also, I've referenced the frequency response at 1kHz level by default, it will still show the voltage gain at cursor position:Release will be shortly after Christmas (once I get past the traditional hangover)

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 24, 2015, 11:29:25 am
content: Example of how to read the THD+N vs Power chart, lots of information can be obtained from a plot like this:

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 26, 2015, 02:31:31 am
content: OK, here is a download link:http://www.thestuffmade.com/audioanalyzersuite/publish.htmI'm interested in knowing about any bugs you find, pm me or just post here in this thread. I haven't fool proofed the software yet, so if you write e.g. "dave" in start frequency, it will likely blow up. Or if you try run multiple measurements at the same time it will blow up, but in general it should be usable.I am only able to test with my version of the Analog Discovery, so any reports on compatibility are appreciated.Note: the spectrum analyzer is not yet implemented. If that annoys you, I can hide the tab. Feature should be available before new year.

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 26, 2015, 03:16:45 am
content: Connections part1:

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 26, 2015, 03:24:19 am
content: IMD measurement connection:

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 26, 2015, 03:35:46 am
content: Output Impedance:

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 26, 2015, 03:44:40 am
content: Input impedance:

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 26, 2015, 03:55:10 am
content: And of course Merry Christmas to everyoneIf you are not feeling it and you need to get in the mood:

author: fpliuzzi
author_rank: Regular Contributor
timestamp: December 26, 2015, 04:21:32 am
content: Thank you very much for making your Audio Analyzer Suite available here. Merry Christmas and a Happy New Year to all.

author: mtdoc
author_rank: Super Contributor
timestamp: December 26, 2015, 04:33:17 am
content: Excellent Jaxbird.I have no immediate use for this but it will be fun to play and learn with and it's great to see someone making use of the ADs full potential. I think it's a remarkable little piece of hardware.Merry Christmas to you!

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 26, 2015, 04:34:49 am
content: Quote from: fpliuzzi on December 26, 2015, 04:21:32 amThanks, Merry Christmas to you and your family, hope you having a great time.Cheers

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 26, 2015, 04:54:27 am
content: Quote from: mtdoc on December 26, 2015, 04:33:17 amMany thanks, Merry Christmas to you and your loved ones.You can use this with any kind of amplifier, from simple opamps to high power amplifiers and tubes etc. It's really just something I felt was missing from the official software provided with the analog discovery. Just to make it easy for everyone to obtain common amplifier performance parameters.

author: jaxbird
author_rank: Frequent Contributor
timestamp: December 26, 2015, 05:40:36 am
content: I hope everyone got some understanding that working on this project has been delaying my promised release of the Analog Discovery Impedance Analyzer (arguably a much more generally valuable product) I know I promised a swift release, apologies about the delays, I will release very soon. It is just a lot more complex than the audio analyzer, so I think the audio analyzer is a good way to test the deployment.https://www.eevblog.com/forum/projects/impedance-analyzer-build-and-experiments/135/

author: Mark
author_rank: Frequent Contributor
timestamp: December 26, 2015, 01:31:08 pm
content: Hi jaxbird, I just downloaded your software and look forward to using it, I have found the Analog Discovery to be a most useful box of tricks since getting one for Christmas last year. I am currently working on an amplifier so I will have a chance to try out your software next week (when I repair the amp... I released the magic smoke!). It's a 50W amp running up to 500kHz.Thank you, Merry Christmas and a Happy New Year!

author: Zero999
author_rank: Super Contributor
timestamp: December 30, 2015, 06:32:20 pm
content: Quote from: jaxbird on December 18, 2015, 07:48:12 amJust a couple of questions.Presumably those plots were taken from the voltage on the amplifier output, not from the sound from the speaker.If the speaker's impedance varies at different frequencies then doesn't the power dissipation and thus output vary significantly?If you plotted the real power dissipated in the speaker, you'll probably find it varies hugely as the frequency is changed. Does that mean the output will be distorted by the same factor?

author: nfmax
author_rank: Super Contributor
timestamp: December 30, 2015, 09:19:46 pm
content: Quote from: Hero999 on December 30, 2015, 06:32:20 pmA1: Yes, the power supplied by the amplifier to the speaker does vary with frequency, a lot. Importantly, it can be reactive power: a capacitive or inductive speaker impedance will simply sling the power right back into the amplifier (which must dissipate it, as heat).A2: The sound output from the speaker does not vary nearly so much. Speakers are designed so that the sound output (usually measured as sound pressure level, on-axis and 1m from the speaker) is proportional to thevoltageon its input terminals. The transduction efficiency, and hence the current drawn from the amplifier, varies with frequency, but this should ideally not affect the output SPL. Usually the variation with frequency depends on the resonant frequency of the various drive units and enclosures within the speaker. Transduction becomes more efficient close to a resonance - though resonances bring problems of their own. The directivity of the speaker also varies with frequency: this may show up in the impedance curve, but even if it does not, varying directivity with frequency means the off-axis frequency response may be anything but flat!All these effects are, in principle, linear and so do not constitute harmonic distortion. Speaker distortion is usually much worse than that of the amplifier, maybe around 1%, though the very best electrostatic speakers (like the Quad ESL63s I'm listening to now) are down around 0.1%.Max

author: Mark
author_rank: Frequent Contributor
timestamp: January 03, 2016, 08:48:50 pm
content: Hello,I installed it on my laptop and could not find a RUN button, so I assumed it was a screen width issue (win7). I installed it on my main PC and still could not find a run button (win7). I then installed it on my win10 machine and still no RUN button... am I doing something wrong?

author: sportq
author_rank: Regular Contributor
timestamp: January 03, 2016, 08:54:11 pm
content: Quote from: Mark on January 03, 2016, 08:48:50 pmI had exactly the same problem on my Windows 10 64bit system.Pete

author: mtdoc
author_rank: Super Contributor
timestamp: January 04, 2016, 06:09:23 am
content: Jaxbird, you're not alone. I just happened to stumble uponJapanese audio analyzer project for the AD

author: Selectech
author_rank: Regular Contributor
timestamp: January 04, 2016, 01:20:04 pm
content: Same issue here,no Run button. Tried on Win 10 x64 and Win7 x64. AD unit works fine with Waveforms on both machines.Dave

author: AudioGuy
author_rank: Newbie
timestamp: January 05, 2016, 01:21:17 pm
content: This thread was recommended from another forum. I'm excited to see where this leads... Jaxbird, keep up the good work.

author: kasey197
author_rank: Newbie
timestamp: January 07, 2016, 04:40:22 am
content: Keep it going jaxbird this is really fabulous !The one thing i wonder about is the lack of balanced outputs - i know that jaxb's posted a SE to balanced converter but i wonder if we can also make use of the two independent waveform generators ?If these can be linked does the UI allow us to set one output to be 180 degrees vs the other ?Haven't actually got my AD yet so cant try it out but praps one of the boffins here knows ...Great stuff again chaps

author: braddrew0
author_rank: Regular Contributor
timestamp: January 07, 2016, 06:58:08 am
content: Nice one jaxbird, love what you've done.As a complete novice at audio (but one that's very interested) how does this compare to something like the Prism dscope?Thanks!Brad

author: kasey197
author_rank: Newbie
timestamp: January 07, 2016, 07:18:49 am
content: funny you asked - I have a prism dscope series iii analyzerUse it mainly for analogue audio projects.It costs a bundle - although still quite bit cheaper than the Audio Precision jobs. Has way better usability than the AP kit and i find it indispensable.So why am i here playing with the digilent ? Because I need the high bandwidth network analyzer bit. The dscope bw is less than 100kHz...1K THD performance of the dscope is ca 0.0007% at 80khz BW, THD+N about 0.002% IIRC. Better at 20k bw obviously but plenty low enough for my needs. And probably an overkill for most of us but I have a weakness for test equipment

author: Mark
author_rank: Frequent Contributor
timestamp: January 14, 2016, 06:07:54 pm
content: Has anyone managed to get this working? If so, what windows version and architecture are you using?

author: fivefish
author_rank: Frequent Contributor
timestamp: January 14, 2016, 06:52:32 pm
content: Has anyone managed to get this working? If so, what windows version and architecture are you using?I got jaxbird software installed on my Windows 10, 64-bit.But since I don't have an AD device, when I try to run it, obviously I get an error message "unable to open Analog Discovery Device, make sure device is connected" That's as far as I got until I get an AD.

author: Audioguru
author_rank: Super Contributor
timestamp: January 14, 2016, 08:02:33 pm
content: The little low power Trident amplifier was designed and patented 19 years ago. They called it Class-T instead of Class-D. It cuts the highest audio frequencies.Trident went bankrupt 9 years ago so I do not know if the ICs are new-old stock or are made recently by a Chinese copy-cat company.

author: jaxbird
author_rank: Frequent Contributor
timestamp: January 24, 2016, 02:41:59 pm
content: Quote from: Hero999 on December 30, 2015, 06:32:20 pmThese two measurements were taken under the exact same conditions, except one was using a precision 4 ohm resistive load and one was using the speaker shown (a PSB alpha B 2 way speaker, manufactured in Canada, you can find a comparable impedance measurement done by stereophile in NY)

author: jaxbird
author_rank: Frequent Contributor
timestamp: January 24, 2016, 02:44:25 pm
content: Quote from: Mark on January 03, 2016, 08:48:50 pmSorry. there was a problem with Win 10, it should be fixed now, please try again and let me know if you have any issues.Thanks

author: jaxbird
author_rank: Frequent Contributor
timestamp: January 24, 2016, 02:46:37 pm
content: Quote from: AudioGuy on January 05, 2016, 01:21:17 pmThanks, appreciate the encouragement, new version available, enjoy.

author: jaxbird
author_rank: Frequent Contributor
timestamp: January 24, 2016, 02:49:16 pm
content: Quote from: Selectech on January 04, 2016, 01:20:04 pmMy bad, it was some auto scaling issue, trying to comply with all these 4k screens and keep the same size, should be fixed, try update or new download.Let me know if you still have issues.Thanks

author: jaxbird
author_rank: Frequent Contributor
timestamp: January 24, 2016, 02:54:09 pm
content: Quote from: Audioguru on January 14, 2016, 08:02:33 pmTrue, but it really is a bridged class D amplifier, not horrible, but as Tripath probably was taken over by Cirrus Logic before mine was produced, it is highly likely it is a copy, but hard to say whether the copy or the original performs better. I can say that it does seem to have it's switching frequency starting around 800khz

author: jaxbird
author_rank: Frequent Contributor
timestamp: January 24, 2016, 03:00:32 pm
content: Anyone trying the software, please try restart, it should update your current version, I was only testing on Win 7 and it was not the same scaling as on Win10, I apologize for that and blame my former employer Bill Gates.

author: jaxbird
author_rank: Frequent Contributor
timestamp: January 24, 2016, 03:11:13 pm
content: as an added bonus for your great mood and bravery, the general purpose spectrum analyzer should be functional in the latest version.

author: jaxbird
author_rank: Frequent Contributor
timestamp: January 24, 2016, 03:19:07 pm
content: Let me know if you still cannot run the basic software, thanks.The current version should say 1.0.0.62, if not, or if you still have issues with this version, please let me know.

author: Mark
author_rank: Frequent Contributor
timestamp: January 24, 2016, 05:31:09 pm
content: Still no joy jaxbird...I tired it on Win 10 tablet and win 7 desktop.It must be a resolution issue, the text along the top is truncated, for example "Total Harmonic Distortion and"Bottom left text is truncated to "Spectru" and Bottom right text is truncated to "Scop D AC" and still no run button.

author: Mark
author_rank: Frequent Contributor
timestamp: January 24, 2016, 05:34:50 pm
content: Screenshot attached from Win7 x64 desktop. My screen resolution is 1920 x 1200.Anything I can try?Thank you!

author: mtdoc
author_rank: Super Contributor
timestamp: January 24, 2016, 06:02:22 pm
content: Same issue here. Windows 7, x64 laptop. Screen resolution 1366 x 768.

author: jaxbird
author_rank: Frequent Contributor
timestamp: January 25, 2016, 12:17:00 am
content: Quote from: Mark on January 24, 2016, 05:31:09 pmQuote from: mtdoc on January 24, 2016, 06:02:22 pmQuote from: Mark on January 24, 2016, 05:31:09 pmI thought I had it fixed, but new version available 1.0.0.63, hope it really is fixed this time. I believe it was caused by my laptop being set to scale 125% during compile.Thanks for having patience everyone.

author: mtdoc
author_rank: Super Contributor
timestamp: January 25, 2016, 02:25:35 am
content: That fixed it! At least on my machine. Thanks for all your efforts jaxbird!

author: fpliuzzi
author_rank: Regular Contributor
timestamp: January 25, 2016, 02:50:58 am
content: Just a quick update to state that v1.0.0.64 is up and running on the Win XP laptop that's sitting on my bench (nice to see that elusive RUN button). Many thanks for this very useful tool. It's going to be used quite frequently.

author: Selectech
author_rank: Regular Contributor
timestamp: January 25, 2016, 05:01:31 am
content: Working fine now on Win 7 X32 with ver 1.0.0.64I'll try iit on Win 10 X64 in the morning.A great piece of test software - thanks. It will get a lot if use.

author: Mark
author_rank: Frequent Contributor
timestamp: January 25, 2016, 07:36:38 pm
content: Quote from: Selectech on January 25, 2016, 05:01:31 amSame here but Win 7 x64, I'll try win 10 on my tablet tomorrow.Thanks jaxbird!

author: jaxbird
author_rank: Frequent Contributor
timestamp: February 01, 2016, 05:44:32 pm
content: Quote from: fpliuzzi on January 25, 2016, 02:50:58 amQuote from: mtdoc on January 25, 2016, 02:25:35 amQuote from: Selectech on January 25, 2016, 05:01:31 amQuote from: Mark on January 25, 2016, 07:36:38 pmGreat!... thanks for the feedback, good to hear it's working.I have added a page for reporting bugs and requesting features:thestuffmade.com/audioanalyzersuite/bugsIf anyone wants to contribute to a better help file, feel welcome to volunteer.. all I can offer is credit though, as it is a free piece of software.Let me know if anyone got success with the AnalogDiscovery2 version, should work afaik, but always nice to get a confirmation.Next I plan to add some more flexibility on the configuration when I have some time, currently most is fixed drop down selection, I'll add free text in those with capability to use short form like 2k or 2M etc and some more error checking on inputs etc.Cheers

author: hugocoolens
author_rank: Newbie
timestamp: February 08, 2016, 04:12:15 pm
content: Quote from: jaxbird on December 26, 2015, 02:31:31 amDear Jaxbird,Is it also possible to run your software using Linux?kind regards,Hugo

author: jaxbird
author_rank: Frequent Contributor
timestamp: February 15, 2016, 09:08:39 am
content: Quote from: hugocoolens on February 08, 2016, 04:12:15 pmIt will probably happen at some point, it's c# code, so should be possible to build against the Mono framework for Linux, but I'll have to rewrite the native wrapper for the Analog Discovery API, so definitely significant work involved.Maybe Wine, I'm not sure what state it's in these days, but might be possible to use under Linux. If you find a way let me know.

author: halej1
author_rank: Newbie
timestamp: February 20, 2016, 09:32:18 pm
content: Jaxbird- this is Awsome! I'm new to EEVblog-- and have seen some of the Audiophoole/Audio Geek bashing. Some of it is well deserved but frankly much of the electronics world is represented by audio and audio analysis. which is why I'm here. Actuallyout of necessity I'm am an Audio guy with limited funds (like all of us) and my gear is aging and failing, so I've had to start learning repairs and testing (albiet I'm new to that part). Really interested in your work and want to use it to analyse some of my gear (sub amps, amps, processers). I have recently purchased (ebay cheap) a Keithly 2015. two reasons- 1) A great bench multi meter 2) the ability to Do THD measurements. Not so much for the ansolute measure but to see if my amps are providing rated power. Sorry such a long lead-in but my question is:When you connect your output signal to test equipment do you attenuate the signal? Basically input would be 0-2V ish and output may get to high voltages for high output amps.Anyway glad there are audio folks on the Blog as well.Thanks

author: jaxbird
author_rank: Frequent Contributor
timestamp: March 04, 2016, 02:32:05 pm
content: Quote from: halej1 on February 20, 2016, 09:32:18 pmThanks, the goal for this project was to provide a cheaper alternative to the already reasonably affordable older HP etc audio analyzers, but adding more features. Performance level should be about the same, it will never get anywhere near the Audio Precision equipment level, but certainly good enough to tell whether an amplifier is faulty and help locate any faults. IMO in reality these 0.000001% specs don't really matter, I am confident no living person can successfully identify the difference between 0.01% and 0.000001% distortion in a true blind test.There is a big difference between audiophoolery and actual audio engineering, many inexperienced people are confused by this difference, thinking everything is audiophoolery and hoping to gain community recognition by calling it out.The immediate limitations are that the Analog Discovery will start clipping at +/-25V input, so that does limit the usability with large amplifiers, but I can easily add a feature to use any division factor, as in add any attenuation (couple of resistors) at the inputs and just enter the factor into the software to scale everything. I can make a board with auto attenuation up to 1000W if anyone is interested.Other limitation is that the outputs are limited to near +/-5V peak (single ended), anything higher than that will need external amplification, but I think most amps will never require more than for full wattage output. Balanced output will also require some external components.Great thing is that the inputs are differential (not floating, but within limits), so measuring things like bridged amplifiers is not an issue.This solutions is much more useful than a Keithley 2015 for amplifier characterization.Cheers

author: jaxbird
author_rank: Frequent Contributor
timestamp: March 04, 2016, 02:45:35 pm
content: Here is a good example of using this software to check the performance of an amplifier, a slightly ridiculous 300B single ended tube amplifier in this case:

author: halej1
author_rank: Newbie
timestamp: March 25, 2016, 01:07:07 pm
content: Jaxbird - still awesome! and thank you for the input to my question. Your software/hardware solution looks really good! I watched your video and was wondering --- you are able to look at the graphs and pretty easily tell if things are good or not so good. Obviously pretty simple on something like THD or THD+N but can you share or direct me to where I can find out, for example -- what is acceptable output impedance (tube, solid state) or input impedance (tube, Solid state) etc... I guess what I'm asking is lot's of people can probably set the system up and get graph but the skill comes with the interpretation.It may be a little while before I spring for an Analog Discovery and your software -- cause I just blew my budget on an Oscilloscope (Rhode and Schwarz 1202) -- Yeah a bit overkill for this type of analysis but I wanted to treat myself (the FFT function is supposed to be very good, though)CheersJohn

author: ci11
author_rank: Regular Contributor
timestamp: March 27, 2016, 02:34:16 pm
content: Hi,I can't get the download to work - got a 'Fatal Error - Unable to find "dwf.dll"'. What am I doing wrong? My PC in Win 7 x64, .Net 4.6.Thanks.

author: AlfBaz
author_rank: Super Contributor
timestamp: March 29, 2016, 05:06:26 am
content: Quote from: ci11 on March 27, 2016, 02:34:16 pmHad the same problem. I've reported it to jaxbird but he seems to be awayIn the interim this work around got me goingDownload and install the old version of waveforms from herehttp://store.digilentinc.com/waveforms-download-only/Select "downgrade" for all the optionsThis should be enough to get his program working.If you want/need the new Waveforms2015 version as well as his software then continue with the followingWith the old version now installed go to C:\windows\SysWOW64 and copy dwf.dll from this directoryThen go to C:\Users\<your user name>\AppData\Local\Apps\2.0\MZKGDAT1.PHM\N5YL8OR9.1AQ\audi..tion_0000000000000000_0001.0000_e5f4f61c851d23cd directoryAt a guess some of those alphanumeric directories may be different in you installation. You need to find the folder containing these files-Audio-Frequency-Icon.icoAudioAnalyzerSuite.cdf-msAudioAnalyzerSuite.exeAudioAnalyzerSuite.exe.cdf-msAudioAnalyzerSuite.exe.configAudioAnalyzerSuite.exe.manifestAudioAnalyzerSuite.manifestPaste the copied dwf.dll hereYou can now re-install the new version of waveforms(2015) and AudioAnalyzerSuite will use the DLL in its local directory first. allowing you to use his software and the new version of waveforms

author: Carrington
author_rank: Super Contributor
timestamp: March 29, 2016, 02:01:31 pm
content: Because of his daily work, we can not expect quick answers from 'jaxbird'. Additionally, he is providing all these software for free. So, in my opinion, we can not demand a full attention.Please, don't misinterpret my words, I'm not reproaching nothing. I also bothered him before with a lot of emails. I repeat,I'm not criticizing, just letting you know about, specially to prevent than anyone get nervous while are waiting for an answer.Cheers.

author: jaxbird
author_rank: Frequent Contributor
timestamp: May 12, 2016, 12:01:47 pm
content: Quote from: ci11 on March 27, 2016, 02:34:16 pmIt seems like it was caused by the updated to Waveforms software, I have added a fix, please try again and let me know if it works now.Thanks

author: jaxbird
author_rank: Frequent Contributor
timestamp: May 12, 2016, 12:22:08 pm
content: Quote from: halej1 on March 25, 2016, 01:07:07 pmThanks, transistor based amplifiers should have very low output impedance, as in way below 1 ohm, more like 10s or 100s of milli ohm. Tube amplifiers cannot achieve that performance because they have output transformers (well some obscure transformer less tube amps do have lower output impedance, but they require insane amounts of paralleled output tubes and are more a novelty)This solution using the Analog Discovery is not something you would use measure marketing specs, but it's something useful to anyone trying to diagnose a potential faulty amplifier, or making sure your amplifier design performs pretty well.It is far superior to purely sound card based solutions in that it's got differential inputs and bandwidth beyond 10MHz, so if anything is oscillating, you will notice right away.

author: jaxbird
author_rank: Frequent Contributor
timestamp: May 12, 2016, 12:33:16 pm
content: Quote from: Carrington on March 29, 2016, 02:01:31 pmThanks, much appreciated Carrington, you are absolutely right, this is a hobby project, I cannot provide quick response to issues, it's simply not possible, but if you provide good bug reports, I will do my best to get them fixed when I have available time.

author: jaxbird
author_rank: Frequent Contributor
timestamp: May 12, 2016, 12:40:46 pm
content: Quote from: AlfBaz on March 29, 2016, 05:06:26 amThe Waveforms software did a switch from 32 bit libraries to 64 bit without telling anyone, usually that would not be an issue, but I had my software set to expect a 32 bit library.Anyway, updated version, it should work with both 32 and 64 bit versions of Waveforms.Sorry for my slow response to this issue, I have been out travelling for some time.

author: jaxbird
author_rank: Frequent Contributor
timestamp: May 26, 2016, 04:34:04 am
content: I have added functionality to compensate for external attenuation as the Analog Discovery (both 1 and 2) will start clipping at +/-25Vpp.Just make a cable/adapter something like this:This example will give 2:1 attenuation, so you'd enter 2.0 as attenuation factor and the software will scale everything accordingly to still provide all the correct values. The attenuation factor is shown in bottom right corner, just click on the value to change it.Keep in mind the voltage/current and resistor ratings when choosing resistor values and that the Analog Discovery input impedance is 1M ohm.

author: jaxbird
author_rank: Frequent Contributor
timestamp: May 28, 2016, 04:12:41 pm
content: Added another feature. On most classic distortion analyzers you have an output to view the distortion and noise waveform on your scope. So I've tried to replicate this feature, it doesn't give any easily quantifiable information, but for those experienced in looking at this waveform it's got valuable information. Basically it's everything coming out of the amplifier except the fundamental tone.My current test subject, a hybrid stereo amplifier with a tube front end voltage amplifier and transistor output stage:And here a view of distortion vs frequency with the distortion/noise waveform in the scope view (the blue trace):Easy to spot the dominant 2nd harmonic shown in the spectrum. Close to a nice sine wave. It's on a different scale as the main waveform. (blue values vs red value indicators)The distortion waveform is not perfectly time aligned with the main trace, I'll probably try fix that in a furture update. Should still provide a useful feature like on the old skool distortion analyzers.

author: AlanG
author_rank: Newbie
timestamp: May 28, 2016, 11:04:27 pm
content: Quote from: jaxbird on May 26, 2016, 04:34:04 amI have not downloaded your latest build so these comments may not be applicable;1) How many decimal places have you allowed for in the attenuation factor? e.g. can you enter 3.16?2) Would you consider adding the option of entering the attenuation in dB? e.g. 10dB (as above)regards,Alan

author: jaxbird
author_rank: Frequent Contributor
timestamp: May 29, 2016, 04:42:57 pm
content: Quote from: AlanG on May 28, 2016, 11:04:27 pmHello Alan,Quick answers:1. The value is stored in a 64 bit floating point, so as many as you like, so you could enter 3.1622776601683795(I think the limit is 15 or 16 something) Just keep in mind it's not meant as a super precision instrument, as in, not competing with Audio Precision instruments in accuracy, but providing many of the same features.2. I did considered this, my thinking is that a ratio would be easier for most users based on resistor values, but I'm open to using dB instead if this is the preferred option. Perhaps an option to enter either attenuation factor or dB would be ideal. I think I'll add that. Thanks for the suggestion.CheersJake

author: bson
author_rank: Unknown
timestamp: May 29, 2016, 10:30:43 pm
content: Great project! Will have to get an AD just to play with it...It would be extremely useful if it could produce the output to an arbitrary USB audio device. That way I could use it to analyze audio DACs.For more complex networks it would also be nice to get phase information, or more specifically group delay. (\$\frac{d\phi}{d\omega}\$) And maybe S-plane decay (\$\sigma\$) to look for a propensity to ring. For a basic amplifier this is probably not of interest, but it quickly becomes relevant when there's a crossover network (with measurement made on the drivers rather than the speaker box input terminals), or for components like DACs or phono preamps where filtering is a fact of life.For the group delay, even a basic approximation is very useful. My HP 3577A takes the phase of sample n-1and calculates the slope to the phase of sample n+1. This becomes the group delay for sample n, in seconds. It will only do it for linear sweeps, but theoretically there's no reason it can't be done for log sweeps just as well in a PC.

author: jaxbird
author_rank: Frequent Contributor
timestamp: June 03, 2016, 04:33:48 pm
content: Quote from: bson on May 29, 2016, 10:30:43 pmThanks, I'm not convinced this project alone would justify buying an Analog Discovery, I guess it depends on how much amplifier testing you door whether the AD's standard features are attractive, it's a bit of a Swiss army knife of measurements.It would be nice to have a decent 24bit, 192/384ksps sound card cover the 20Hz to 20-40kHz range to get more dynamic range while having the Analog Discovery measure the levels. It would be fairly simple to implement code wise, but it would require some external hardware for input/output switching, attenuation selection etc. One of the main issues with using sound cards is that you really have no idea what level they are working at, and at what level the input will start clipping and when the output clips or maxes out. Plus if you are e.g. measuring a bridged output (like most class D amps) it could turn into an expensive disaster to connect the amplifier negative output to a single ended soundcard ground input. Also unlikely the sound card output level is high enough to bring many power amplifiers into clipping. Perhaps some optimization for a specific sound card (preferably external usb connected for laptop usage) could be a good solution. Definitely worth considering.Group delay and phase are likely features I will work on adding in future updates, until then I'd recommend software like ARTA for these measurements (using a sound card). Personally I have good experience with ARTA, though I mostly use it for speaker measurements.Cheers,Jake

author: jaxbird
author_rank: Frequent Contributor
timestamp: June 03, 2016, 08:09:43 pm
content: I was thinking about building a complete ADC/DAC maybe 24/32bit/512ksps using the best commercially available converters, and a CM6631A for usb interface for both analog and digital testing and writing some kick ass software for it, but I think it's too much work and I'm just one person, so I think I will stick to making some generally usable software for the Analog Discovery for now.

author: RandallMcRee
author_rank: Frequent Contributor
timestamp: June 03, 2016, 09:35:42 pm
content: In the ADC/DAC arena there is also this offering:http://www.quantasylum.com/content/Products/QA401.aspxfolks on diyaudio seem to like it:http://www.diyaudio.com/forums/equipment-tools/231401-quantasylum-qa400-qa401.htmlQA401 is $429.

author: jaxbird
author_rank: Frequent Contributor
timestamp: June 03, 2016, 10:29:40 pm
content: Quote from: RandallMcRee on June 03, 2016, 09:35:42 pmThanks, that does look very interesting, but at $429 it's a bit of an investment for something that might measure up to 80-90kHz (they don't specify bandwidth, so it could be a lot less) and give an extra 20-30dB dynamic range, it still needs attenuation for amplifier measurements, it seems the maximum input is close to that of the Analog Discovery, but it does appear to have differential inputs.I'm not clear whether this device works like a sound card or it's got some proprietary USB interface.

author: timb
author_rank: Super Contributor
timestamp: June 04, 2016, 11:02:34 am
content: Quote from: jaxbird on June 03, 2016, 10:29:40 pmIt's proprietary, which is one of the selling points. The idea being that because it doesn't show up as a standard USB audio device, you don't have issues with other software (or the OS itself) changing the gain during a measurement.They provide software that's fairly comprehensive; there's also third party support from at least one other popular audio analysis suite.Seems like a nice system, but I'm not really sure how much better it is than a ~$100 24-bit USB ADC/DAC unit combined with one of the many audio analysis programs available. I guess the QA401 has built-in attenuation and can take a differential signal that's over 50Vrms, which is nice.

author: jaxbird
author_rank: Frequent Contributor
timestamp: June 08, 2016, 10:47:54 am
content: Quote from: timb on June 04, 2016, 11:02:34 amThanks, I think not relying on the volume setting is a plus, their specs are confusing, some places it says single ended, other places differential, and this was in one of the specs:Input AC Impedance 10KInput Clip Level +3 dBV = 1.41 Vrms = 4VppThat does require some external attenuation, not sure if they have anything to compensate for external attenuation, or even measuring output power.

author: jaxbird
author_rank: Frequent Contributor
timestamp: June 08, 2016, 11:10:29 am
content: Video showing new features in use:

author: Oneminde
author_rank: Regular Contributor
timestamp: June 04, 2017, 11:25:36 pm
content: Thestuffmade webpage is down and I really need a copy of the Audio Analyzer Suite, can anyone please share it ?

author: sarel.wagner
author_rank: Regular Contributor
timestamp: June 16, 2017, 10:08:11 am
content: Ditto please, thestuffmade website is still down, can someone please share the download? Or better dump it on dropbox or googledrive and share please?Rgrds

author: Marco
author_rank: Super Contributor
timestamp: June 16, 2017, 06:13:52 pm
content: Quote from: jaxbird on June 03, 2016, 04:33:48 pmThere is an alternative, you can combine the two channels into one with a simple attenuator. Obviously this will drift a lot with temperature, but with online calibration it can work. In fact with online calibration you can create a ultra pure sine with such a makeshift DAC.See "Low Cost Ultra-Pure Sine Wave Generation with Self Calibration". In short you selectively low pass the DACs, because the low pass only affects the harmonics for the DACs you can detect/correct them even with an ADC which itself is also significantly non-linear. The software is not entirely trivial, but with the ADC/DAC using one clock it will be simpler than in the paper (no need to detect the fundamental).

author: Jelcke
author_rank: Contributor
timestamp: July 01, 2017, 11:28:21 pm
content: Inspired byI just bought a Analog Discovery 2 but now the software is not available anymore!Could anyone or jaxbird share a copy with me please.Thanks!

author: bitseeker
author_rank: Super Contributor
timestamp: July 11, 2017, 05:53:37 pm
content: The Audio Analyzer Suite cannot easily be shared. Why? Because the download was only an installer. It did not include the software. Only after running the installer was the latest version of the software downloaded directly from the site and onto your computer. So, without the site being up, the required installation package is not available even if you had downloaded the .exe file before the site went offline.

author: azer
author_rank: Regular Contributor
timestamp: July 13, 2017, 07:10:01 pm
content: Try the attached files, it is the files downloaded by the installer.I don't think it is the latest version. I don't have the AD here and it complains that it can't be found on startup so I don't know if it runs ok without the server online.The files are located in a subfolder of c:\users\yourusername\AppData\Local\Apps\2.0\ if anybody has one of the later versions.

author: bitseeker
author_rank: Super Contributor
timestamp: July 13, 2017, 09:38:42 pm
content: Thanks azer. I don't know if it'll run as-is from the already-installed files. My PC already has all the proper registry entries, folders, etc. created by the installer, so I don't know what it'll do on a clean system. Someone very familiar with the Windows installer may be able to take the next step to make it installable. I see the manifest and config files in your archive, but haven't worked with Windows installers in decades, so I'm unsure if that has all the necessary information.The processor architecture in my version is different from yours. Interesting. So, the app and/or .Net version that they were built for may be sufficiently different.Mine:<assemblyIdentity name="AudioAnalyzerSuite" processorArchitecture="msil" version="1.0.26.374" />Yours:<assemblyIdentity name="AudioAnalyzerSuite" processorArchitecture="x86" version="1.0.358.107" />

author: micro_freak
author_rank: Contributor
timestamp: July 28, 2017, 10:40:23 pm
content: thanks for the zipped files, I downloaded and installed them in a directory.I tried to run the files, with the new dll, the program will start on winX and Win7, but no run button appears.no joy with older dll.Anyone has an idea if it is missing a dependency or something similar?

author: bitseeker
author_rank: Super Contributor
timestamp: July 28, 2017, 10:51:54 pm
content: Could the button be outside the window? I vaguely recall some issues due to font scaling. If your Windows is at 125% or higher, see if changing to 100% helps. If I am remembering correctly, the answer may be in this thread or elsewhere on the forum.

author: micro_freak
author_rank: Contributor
timestamp: July 30, 2017, 03:59:06 pm
content: Thank for the advise Bitseeker.Changing the view to 125% on my win7 laptop force the layout to change and the run button appears.No luck with my winX desktop .Settings and help menu do not work, not sure if there is important functionnality not accessible.I made some loopback measurements on my laptop so I guess it will be fine with an amplifier.I suppose the only way to preserve measurement is to take screenshots, there does not seem to be a save data of some sort.at least the most important aspect of the software appears to work fine.

author: sarel.wagner
author_rank: Regular Contributor
timestamp: July 30, 2017, 05:19:36 pm
content: Thank you Azer for the files. I do not yet have my AD but it is on Order. Thank you for confirming functionality micro_freak. So glad I got the filesand now do better audio measurements.Rgrds

author: micro_freak
author_rank: Contributor
timestamp: July 30, 2017, 09:03:36 pm
content: Hi sarel.wagner, unfortunately, it is not fully functionnal.This afternoon, I tried to make some measurements on one of my old amp, and the display does not scale well on some screens.Worse than that is that some do not work. especially the frequency responce, I double checked with my scope in parallel.I did not try the input impedence, output impedence and spectrum analyser.

author: azer
author_rank: Regular Contributor
timestamp: July 31, 2017, 01:53:23 pm
content: It's the version he posted in Dec 2015 so there are likely some bugs that were fixes since then.I know there were some fixes for win10, image scaling and the updated waveforms software.We would need to wait for somebody that installed a later version to upload theirs.

author: Neganur
author_rank: Unknown
timestamp: July 31, 2017, 06:42:02 pm
content: What was the file called again?I found something on my NAS called AudioAnalyzerV1.9.exe, could that be it? I might have the sw installed still but haven't used the stationary PC for a few months.EDIT: I have an installation of ImpedanceAnalyzer file version 1.0.0.507 and AudioAnalyzerSuite file version 1.0.148.334 but crashing with fatal error since I don't have the AD connected.Can upload the files if they're of any use. (Just verified, the version uploaded in an earlier post was 1.0.358.107 - so my files are older)

author: abzza
author_rank: Newbie
timestamp: August 14, 2017, 10:06:30 am
content: @Neganur - yes please, please upload! Just bought my AD2 and this would be seriously handy.

author: micro_freak
author_rank: Contributor
timestamp: September 10, 2017, 06:56:49 pm
content: The latest version of wafeform 2015 now support the use of the spectrum analyser trough the use of scripts.there is an example of it's usage on the Digilent forum.https://forum.digilentinc.com/topic/4383-using-script-with-spectrum-on-ad2/?page=0#comment-17254I tried it and it works, I am trying to convert the thd value from dbc to %, the math functions are probably there, i just can,t figure this javascript.I can convert the values in a speadsheet but it is not convenient.for those like me who do not have access to a working copy of the audio analyser suite, this is a step in the right direction.You have to adjusts wavegen levels and monitor the output prior to lunching the script.I supppose there are other also working on this script, so don't despair, a working solution is cooking and should be served soon!

author: bitseeker
author_rank: Super Contributor
timestamp: September 10, 2017, 10:58:34 pm
content: Thanks for the update, micro_freak.

author: AlfBaz
author_rank: Super Contributor
timestamp: September 11, 2017, 02:26:36 am
content: Curious, has there been any online chatter or conjecture as to why jaxbird has pulled the pin on both the Audio and impedance analyzers

author: bitseeker
author_rank: Super Contributor
timestamp: September 11, 2017, 06:58:09 pm
content: I haven't heard anything about what happened to jaxbird and his software. It's still a mystery.

author: micro_freak
author_rank: Contributor
timestamp: September 13, 2017, 09:07:09 pm
content: Hi, for those interested, I posted a new version of the script I am working on.https://forum.digilentinc.com/topic/4383-using-script-with-spectrum-on-ad2/?page=0#comment-17254Using script with Spectrum on AD2 - Scopes & Instruments - Digilent ForumIt is not too complicated to use, set the wavegen voltage to obtain the desired output from your amp under test prior to lunching the script.also note that if your frequency responce is below 100kHz, the values for high frequencies are invalid. You need at least five harmonics to compute a valid thd figure.The script is slow compared to the video I have seen of the audio analyser suite, but it is better than nothing for those like me who do not have a working copy.In hope that it is usuful for other too!

author: bitseeker
author_rank: Super Contributor
timestamp: September 13, 2017, 09:21:01 pm
content: That script has undergone quite some enhancement. Nice job.

author: arahmed
author_rank: Newbie
timestamp: April 01, 2018, 08:41:11 pm
content: The websitewww.thestuffmade.comisn't working anymore. Does anyone know where I can download a copy?Thanks in advance.

author: Audioguru
author_rank: Super Contributor
timestamp: April 02, 2018, 12:00:06 am
content: Some people do not like music and say all sound systems sound the same are deaf to high frequency audio harmonics, noise and distortion and cannot "carry" a tune.Most old people without hearing aids and younger people who were exposed to loud sounds are deaf to high audio frequencies.Tripath made some "class-T" audio ICs then they went bankrupt in about 2007. Their remains were bought by Cirrus Logic but I do not know if they made the class-T ICs. I think a Chinese company owns them now but their products might not match the originals.

author: kimahansen
author_rank: Newbie
timestamp: November 21, 2018, 01:47:50 pm
content: Good news:Audio Analyzer Suite 1.0.0.75 Available for Download

author: bitseeker
author_rank: Super Contributor
timestamp: November 21, 2018, 05:22:19 pm
content: Welcome to the forum, kimahansen. That's great news. Glad to see he was able to find a place to upload new versions.Note: It's not necessary to watch the video as it's pretty much just a placeholder. The download link is in the video's description.Subscribe to his YT channel,TheStuffMade, as it appears that's where he's going to announce new releases now.

author: Bassman59
author_rank: Super Contributor
timestamp: November 22, 2018, 01:40:55 am
content: Can you post the URL for the download link?

author: RGK
author_rank: Contributor
timestamp: November 22, 2018, 02:26:42 am
content: Quote from: Bassman59 on November 22, 2018, 01:40:55 amhttps://sabercathost.com/9v2u/AudioAnalyzerSuite_1.0.0.75_no_installer.zip

author: jaxbird
author_rank: Frequent Contributor
timestamp: June 21, 2019, 06:45:08 pm
content: Latest version can be downloaded here:https://www.dropbox.com/sh/w3r2wycgdox8vxo/AADNYyxsmtO4UDaTuaFLPNA0a?dl=0Details here:I am currently working on a new version that will allow using windows sound cards together with the analog discovery.

author: jaxbird
author_rank: Frequent Contributor
timestamp: June 21, 2019, 07:03:04 pm
content: Teaser on general sound card version:

author: bitseeker
author_rank: Super Contributor
timestamp: June 21, 2019, 09:15:39 pm
content: Thank you for keeping this project going!

author: Gary.M
author_rank: Regular Contributor
timestamp: June 22, 2019, 12:46:30 am
content: Super, well done! Appreciated!Sent from my MI 8 using Tapatalk

author: hhappy1
author_rank: Contributor
timestamp: July 20, 2019, 03:53:11 pm
content: I think you are the best.I hope there's a program for sound cards.Thank you very much. Sir~~

author: Audioguru again
author_rank: Regular Contributor
timestamp: July 20, 2019, 06:58:04 pm
content: I like high fidelity audio with very low distortion and a flat frequency response from 20Hz to 20kHz.But some or many people are "tone deaf" or are actually deaf and don't care. They don't notice severe distortion and a telephone frequency response of 300Hz to 2.5kHz is fine with them since their most frequent spoken word is "What?".

author: trevwhite
author_rank: Frequent Contributor
timestamp: July 20, 2019, 07:17:47 pm
content: How difficult would it be to get this working with Picoscope SDK? I wonder if Picotech might even offer some financial assistance to help make this happen?Trev

author: LightningPhil
author_rank: Newbie
timestamp: February 17, 2020, 09:23:37 pm
content: This is various shades of awesome. Downloaded and will give a go.Cheers!

author: speedy6963
author_rank: Newbie
timestamp: February 21, 2020, 11:27:57 am
content: Any update on the soundcard version ??I would like to try it with thishttps://www.amazon.com/MOTU-M2-USB-C-Audio-Interface/dp/B0812B26TNQuote from: jaxbird on June 21, 2019, 07:03:04 pm

author: bmsorin
author_rank: Newbie
timestamp: February 21, 2020, 02:23:26 pm
content: I am intirested too in latest version to test with focusrite scarlett.Thank you.

author: hhappy1
author_rank: Contributor
timestamp: March 26, 2020, 02:14:46 am
content: Quote from: bmsorin on February 21, 2020, 02:23:26 pmWow, that's amazing.Where do you download programs for sound cards?I shall be glad if I find it.