I use to work with sound cards as spectrum analyzer, since about 13 or 15 yrs ago, analysing engine knock sensor signals, while I tune the ignition advance time. Because the frequency of engine knock depends only on the piston bore diameter, and it's perfectly human audible, sound cards are perfect to use. And I can measure two channels at same time: engine phase and the knock sensor. So I can detect what's the real knock, in what cylinder(s) from some other noises like a bad adjusted valves, huge piston clearances and other engine noises. The other way is to use a simple audio amp and listen the signal generated by the sensor. It's obvious the hard way. Very hard.
Yeah, about that same time I was tape recording my chainsaw and playing it back to Windows 98 through Sound Recorder, then analyzing and displaying using Quick Basic. Looked just like a scope with 2 cursors for analysis. Very revealing I tell you. Also recorded firecrackers. It's not what you'd expect. :)
@@antoninperbosc1532 wow... I used to do this more then a decade ago. :P To do something like this now, and make a video, I will need a car/engine with a programmable engine management system (Programmable ECU) with a properly knock sensor, perhaps a good audio pre-amp, an adaptor cable (from the knock sensor to the mic/pre-amp input) and of course, the notebook with a sound card. And a car/engine dynamometer... If you are curious about the engine noises, I found a video from HPA ( ruclips.net/video/66okwgg6Rrw/видео.html ). I didn't found any kind of video with the same things that I used to do. Sorry. :(
How about hacking a memory stick with a resistor ladder to grab analog data at ddr2,3 rate? Just increment the address bits and do a read of the data pins which are hooked to a ladder. Then display by changing the rw pin.
Nice video and brings up some memories of the past. Back in 1997 I used a PC sound card to decode the DCC track signal of my model railroad and display the commands that are coming along the track in real time. The DCC signal is a pulse width modulated square wave with a maximum bit rate of about 16kbps, so it was quite easy to decode with 44.kHz sampling. As interface I used a resistor in each wire to the track and two antiparallel diodes to limit the input voltage on the microphone input. Software was written in Borland Pascal for Windows, running on a 486 with Windows 3.1. Tempi passati ;-)
@@sookmaideek not necessarily. Borland Turbo Pascal and Borland Pascal are different, where Borland Pascal was more high end, and contained more libraries out of the box.
the "loss" of your low-pass filter only comes from the limited low input impedance of your sound card. You can easily check it by using a filter with 1 kΩ and 160 nF. A passive RC-filter is lossless in the passband if driving a high-impedance input.
@@antoninperbosc1532 distortion is not related to the dampening of the signal. The RC filter is linear for a sine wave of constant frequency, even if it is connected to a low impedance input and does not cause distortion. Distortion is generally caused by non-linearities in an amplifier. Other problems are caused by the frequency dependence of the phase shift if one considers a mix of incoming frequencies like voice or music.
I use a similar software (soundcard oscilloscope), its very easy and gives real oscilloscope like interface. I also use two silicon diodes (one forward, one reverse biased) in parallel to the potentiometer on the input signal and ground wire to bypass any AC voltage greater than 700 mV. It saves the soundcard from any accidental over voltage when the potentiometer is not correctly set.
Did the same . But added a 2 pole 6 way switch. It has a though , 50 R , 8 R , 600 R dummy load , a diode for AM demod , rf signal tracing & rectified output for a DVM . Signal tracing can be via the pc speakers if necessary & the microphone boost can up the gain . That's af or rf demodulated signal tracing . ( Noise can be reduced by subtracting the unused channel #2 from #1 ) . I almost fitted a calibrated RF wave absorption & notch filter . But the box wasn't big enough 🤦♂️ Note this is not isolated so not for high voltage or tube work !
@@AndreasSpiess Same here. I might not use this info today. But now I know where to look when I *do* need the info. I do need to do some audio experimenting later. Thank you.
It is pretty easy to bypass the capacitor near the input or output jack on the soundcard to be able to input/output DC signals as well. I've done this both for using audio input as an oscilloscope, and for using the output as a signal generator for a laser galvanometer and it worked great for both.
@@iforth64 : AC coupling for soundcards (and a fair variety of other things) is the norm, because it reduces the chances both of ground loops, and of safety hazards.
@@iforth64 DC means V+ and Vzero with V+ will push the speaker forward then Vzero will return the speaker back to natural state. Then AC means V- will pull the speaker backward deeper and quicker to compare Vzero.
@@iforth64 In an amplifier you do not want to amplifie DC offsets since at high levels they will push the amplified signals to one of the powerrails. If that happens the peaks of the signals are cut off which causes extreme high distortion. You can not control if the applied input signal has a DC offset. But with a capacitor in series of the input you can block any DC offset preventing this problem.
Nicely done! I figured that this was possible back in the late 1990's but never found the time to explore using a sound card as an oscilloscope. It's great that other folks had the same idea but actually put in the time to bring it to reality.
Nice one Andreas. If you learn something (which we may already know) it's (still) _your great way of presentation_ that makes it fun ... *Love That* 😘👍
I just remembered this one ! If the software has a audio analyser but you can't inject a sweeping signal . Try a simple wight noise generator injected into the amp . You will see the passband response on the analyser . It has limited uses with RF also , tune for maximum noise or work from a good audio stage into the radio / unit / DUT . Like passing a 100 khz square wave ( & overtones ) through a radio receiver . Old tricks we used when all we had was time , a box of scrap , war surplus & brass screws !
Using white noise as an input is a great possibility. Particularly with the new broadband SDR receivers. You immediately get the full frequency response.
A deep dive into existing 'stuff' right under my nose; presented fully as always. Amazing what free software is 'out there' as you show. A very helpful video. I, of course, have a wonderful oscilloscope but didn't even think I had one in my PC. Very enlightening.
Easiest thing to experiment with - is to connect transparent diode to line input. Now you will be able to receive IR signals from remote controls. If you write corresponding software of course :)
I tried that. The soundcard input impedance is extremely low, it doesn't work. Buy an inexpensive PC oscilloscope. Considering the outrageous price of video cards nowadays, a PC oscilloscope is a fraction of the price.
".. all newer pcs have .." ... Intel skipped that class, my 11th gen Intel NUC doesn't even have a sound card! (relies on display over usb-c with audio, which they didnt:/)
Some time ago, before I got a scope, I considered using one of my audio interfaces as a scope. The 24-bit resolution on the converters are exquisite, but the sample rate leaves much to be desired. My scope is 1 GSa/s, whereas my interface maxes at 192 kHz. (But I can measure up to 10 channels! Or if I use multiple interfaces, 34 channels at 96 kHz.) I think I did actually try this at one point, but I seem to remember there was a huge DC offset, and I was worried I'd blown something. They all have input caps, but... still scary. Never again. (Fortunately, they're all good.)
After watching the video in full, I take back my "never again" comment. I can see how valuable it'll be in the audio domain. As long as I know I won't cause problems for myself. Idiot-check with the scope or DMM, then detailed measurements with REW. 😁
There's alot you can do with a PC but it is not realtime due to latencies in the operating system and USB protocol. This doesn't stop you from doing non-realtime (record and analyse) however for an oscilloscope realtime is needed for trigging. Only reason you may not want to use a PC is isolation - tube amps with hundreds of volts and PC are not a good combination without specialist hardware. A differential probe helps and could be used with a sound card - isolating and being safe. The only down side to a PC sound card is the lack of control over the processing - some operating systems perform conversion, and apply human ear perception equalisation etc. MacOS used to be a pain for that, the later operating system allows the developer better options to prevent this. I wrote a Bode plot AWG for my 1104x-e and currently writing a high resolution spectrum analyser (1Mpt and 1MSPS). You may want to use flattop filtering on the FFT as this provides the best measurement value.
Triggering does not need realtime. Just write the data into a ring buffer and evaluate any trigger condition at your time. This also enables pre-trigger, where you see some data leading to the trigger event.
What realtime is fast enough for you? It is easy to get ~100ms latency. ~10ms is harder, but possible too. ~1ms looks like maximum of what PC + sound card can achieve.
That's why you don't use WaveRT/DirectSound Drivers on Windows, or CoreAudio on MacOS. You have to use audio drivers which bypass any OS/Driver processing, putting the audio codec in a sort of "promiscuous mode". I don't know how that can be done in MacOS, but in Windows you use ASIO drivers for that. ASIO4ALL project provides a free of charge ASIO driver which works with the common Realtek codecs which don't provide ASIO by default.
Thanks for this video! I just look at diy pre-amplifier for electric guitar. With your recommendation I can verify frequency response of pre -amplifier, when it is ready. In the meanwhile, do you have experience with external usb oscilloscopes, is there a good one, not very expensive, possibly from aliexpress?
I only own the bench oscilloscope, so I am not a big help. Usually, you get what you pay for if you go with the better-known oscilloscope brands: The more you pay the better the specs.
I have been using the free DAQARTA demo program which allows unlimited use of its oscilloscope and a few other functions, while its signal generator is limited to 30 times or 30 days use after which you need to purchase it or re-install the program for another 30 times/days of fully functioning demo, which includes its most important tool to me: an LCR/ESR meter which can measure as low as 1mΩ resistance, 1pF to at least 10,000uF and less than a uH resolution (I think as low as 1nH), though such low measurements are filled with noise, depending on the soundcard's S/N ratio. I use an Audiophile 2496 soundcard, so the noise is at least 10 times lower than on the standard cards.
@@AndreasSpiess Even with my 2496 sound card, actual usable resolution for inductivity is 1uH, with 0.1uH digit changing all the time and you sort of see which number is the most frequent. Below that, numbers are changing too much to be useful. All that is needed besides soundcard (and a cable) is a reference resistor and probes, and the ability to short out the reference resistor when calibrating the software. I plan to add an external output amplifier so that I can use a lower value REF resistor (improves S/N ratio) and a pre-amp at the probe (also to improve S/N ratio). One channel is used as an output, and 2 channels are used as an input - one takes signal before and the other after the REF resistor, comparing their phase shift and relative values to automatically give out results as capacitance or inductance, along with ESR and DF for caps and resistance and Q factor for inductors.
Well done again Andreas! I was using something similar few years ago and not just on PC, but also using a tablet! It was working well, for what it is and mainly I had fun with it and so did my friends, for whom I made the cables for. Also old phones can be used to play with this kind of stuff, since the phone is old and not in use! I'm a Tracfone user so every year I get a new phone and my wife also, so at least 2 phones per year are dedicated for all kinds of projects, including Mooshimeter, Pokit Meter and few of my regular meters that have Bluetooth built in for remote measuring. Thank you again Andreas!
I was duing some experiments with audio signals and misusing a sound card. I was using just an ordinary integrated Realtek HD Audio. I've discovered that the sound chip is doing some funny stuff to the signal. Namely it seems it has some kind of autogain, which can't be controlled or turned off from the software. Also laptops usually have only a microphone input, which is more difficult to use for recording arbitrary audio signals. So it's a good idea to carefully test your equipment, if it's suitable for the task.
That's true, especially for laptops that have limited I/O and usually combine headphone and mic together. The easiest and less risky way is to use an external USB audio adapter with proper line in/out. Worse case you kill the adapter but keep you computer safe.
Using an external sound card is what I recommended, too. They are no more very expensive. But I agree, there is always a possibility that the signal is distorted by the PC.
I think the point is that if you don't need it for high precision and rarely, it's probably good enough. If you're doing anything that requires serious precision, you'd probably want to just buy a quality bit of kit.
I've used REW and a Dayton Audio UMM-6 USB calibration microphone to set up a couple church sound systems. That software is crazy powerful -- I've seen commercial solutions that aren't as comprehensive. Anyone interested in playing with sound systems, especially measuring speaker response, would do well with this combination. 👍️
@@AndreasSpiess Goodness... if it falls under the Acoustic domain, it's probably measurable. I won't claim to know everything it's capable of, though. 😁
Excellent video and a very good introduction to sound cards and their benefits to signal processing. It's also a trip down memory lane... Many years ago (Pentium 3 and 4 era) I used a sound card to decode/encode tone signals in combination with radio equipment (CTCSS, SelCall tone sets like EEA, ZVEI I etc...). What a wonderfull time...
We still use the sound cards to decode signals in amateur radio. This is a cheap and high-quality procedure. I did not know that this trend started already long-time ago.
@@AndreasSpiess The encode/decode with soundcard project was my thesis project. I started with radio communication for my job in the early 90-ties. In that era our relay stations were connected with M1020 orM1040. I started a project (which got cancelled...) to interface radio's with ethernet, today known as RIPS (Radio over IP Streaming) to get rid of the expensive leased lines. A little later... the era of Tetra pushed back all the older equipment and projects to maintain/improve the analog network. I miss this older period somehow... I guess it's a little nostalgia.
No one here seems to have mentioned USB isolators yet. Isolation on the USB side would seem a good general purpose approach that would be transferable between lots of use-cases where you want your precious PC connected to a bench of not-yet-proven project. A USB isolator must be a fairly tractable thing to implement, but I've done a load of searching on Amazon and not found anything that definitively performs this task. I'm sure they must exist and I'm just failing to find them. Thoughts ?
White gloves and the tophat always make your videos feel special. It's like you're about to show us diamonds and artifacts. So classy! Also thank you for this. I've needed a way to analyze signals without a scope.
Unfortunately very few modern computers and external sound cards have stereo line input, a mono mic is predominant, which makes it difficult to input signals. My oldish PC is good in this respect. Two other free softwares are Digilent Waveforms (front end for their instruments but includes a sound card option) Soundcard Oscilloscope by Christian Zeitnitz - a bit dated interface but does the job reliably
You should look at more expensive sound cards. I have a thing sitting beside me with stereo mic inputs, and 8 channels of balanced line inputs and 8 channels of balanced line outputs. Of course it cost me a few hundred bucks.
@@alexandern8671 No it doesn't. The title of the video isn't "make a scope for free", it is "use your sound card as a scope". A $300 sound adapter is still a tenth the cost of a $3000 scope, which is about the minimum these days for a decent scope. And the scope won't have the gain dynamic range and noise floor of the sound card, nor is it likely to have FFT or spectrum analyzer capabilities, and may not have a way to record what it sees on the screen. And you can get that $300 sound card for maybe half that used on eBay. I've got both a scope and a cheap PC with a good sound adapter, and I use both. They have different strengths.
@@lwilton Agree with your point regarding the title of the video. However I do not think someone with a budget of $300 should invest in a sound card for the purpose of scoping some signals. Andreas has discussed the downsides - no DC, limited frequency range. If one has such a card already like you then of course it is nice to repurpose it though. I can think of some niche applications where the increased vertical resolution could make a big difference but they are hardly the mainstream. Can you please give some common use cases that would benefit from increased vertical resolution?
Thanks for your video! I think this is a great idea! I just wanted to say, that maybe you can use an optocoupler between the signal and the sound card's input. This would protect the sound card in a better way than the potentiometer.
Opto-isolators usually introduce a lot of non-linearities (as sdjhgfkshf mentioned). So this would disturb the signal. Maybe it would be better to use an external soundcard and a USB insulator.
I actually did this years ago with my little netbook when I was putting a new stereo in my mum's car. I don't remember the programs I used but it was very handy to identify which wires went to which speakers.
@13:38 regarding disadvantage #4 that sound cards don't measure DC: For most soundcards that is true. However some soundcards (such as the MOTU 624) have DC-coupled analog outputs, meaning that those outputs can provide DC (and low frequency) output. Though I don't know if there are soundcards with DC-coupled inputs.
@@AndreasSpiess I was going to suggest that. ADCs are mostly DC-sampling devices and most sound-cards should be able to sample DC by shorting the input caps, unless high-pass filtering was done in the feedback or the DSP.
For maybe 20 dollars you should be able to get an audio-quality stereo I2S ADC and DAC, feed them through fast optocouplers, and send that data to a USB MCU that can send it to your computer. Arguably there are some computers that will take digital audio signals like SPIDF and some ADC/DACs that can produce it such that you don’t even need the MCU. Then I’d have a 6+ resistor range switch followed by clipping diodes for the input, and a couple of different gain amplifier settings for the output. Maybe an input buffer amplifier running on some larger voltage rails, for input impedance purposes.
@@AndreasSpiess from what I hear the Arduino Pro Micro has a fair bit of code written for it out there, acting like a sound card is almost certainly one of those. If that bitrate isn’t fast enough then the same should apply to the STM32F103, though they’re a little tougher to get programmed. Another option is using an FT232 and SPI ADCs/DACs, not sure how much programming they need, but I’d guess it would be less than the STM32 and still give you full speed USB2.0. For USB3.0 purposes there’s the Cypress FX3, but from what I hear that’s a pain to program and it’s only really necessary for really high bitrates or SDR territory.
These are SDR radios, work for different frequencies and need different software. But the principle is the same: Use the power of the PC to reduce hardware cost.
If you get a professional sound device (as opposed to an Ali-Express "professional(tm)" sound thing) you should be able to handle up to about 24Vpp of both input and output levels without distortion. Obviously if you are working with unknown-level signals it would be a good idea to build a +-15V clipper for the input signals.
@@AndreasSpiess The Scarlett qualifies as a professional device. Basically if it has an XLR jack and 6mm TRS jacks, it is likely to be +20dBu or better. It should be able to output similar levels into 600 ohms. Pretty much all of these devices run the internal opamps from +-15V, so subtract about 6V from that to get the max direct input level or max output level.
I already have a pretty good scope, but I think I'll stick to physical circuits when it comes to signal generators. Having said that though, these programs do look usefull.
Super cool! Very interesting in this topic. I've search for these setups years early, however, I did not able to fully setup a set of software and hardware in my computer. Thank you for sharing this!
While audio card oscilloscope is handy, there's some caveats; the processors and / or ADCs, and DACs used by most sound cards tended to be slow so 48 kilohertzs bandwidth is usable at most, if that. However, it's cheaper to do it and get done quickly. And I strongly recommend that the line or microphone inputs be protected - the same way you would do when putting together a few more extra coaxial oscilloscope leads for the most expensive kit.
The Java sound device not being able to generate beyond 22 kHz points to it internally capping at CD sample quality, 44.1 kHz. Per the Nyquist-Shannon sampling theorem, the highest reproducible frequency is half the sampling rate used.
I don't even trust to connect a USB oscilloscope to my computer, my computer is way too valuable to risk damaging it... I would NEVER do something like this and if your computer is valuable to you I highly recommend you NOT TO DO THIS. We all make mistakes so it's a matter of time, not a matter if it would happen to you to make a fatal mistake and destroy your computer.
I find it annoying that people refer to the two dollar chip that comes on the motherboard as a 'sound card'. It is not a card, and it cannot be removed or replaced like a card. No one refers to CPU video as a 'video card'. External boxes are Audio Interfaces - and also Not Cards! So why? Lazy speech, as usual.
I have tinkered with sound cards as oscilloscopes. I'd suggest connecting diodes in parallel to the 3.5mm mic input to clip their voltages to 0.7V to protect the sound card in case of input over voltage.
My sound card (SB Live!) survives even signals with 4 diodes protection (twice your level). I suspect that it may be capable to use even higher voltages.
Optocouplers are not linear and would not help in this situation because they would disturb the signal. You can use an isolated USB connector to connect an external soundcard and it would work.
too long, to boring, too academic, little or no use in real life, you re just the kind of puppy that likes to hear himself talk, i bet your wife plans some divorce
Is there any cheap way to use this for 0-5V Digital Signals? The Frequency Domain Analysis is interesting but of little use for the average DIY guy I think ...
@@bbogdanmircea I just wrote a comment about the same topic. I can imagine that you can read signals but they might not be stable, but maybe you can read voltage changes from high to low. I would love to know that
A typical consumer grade soundcard is about 1V rms, which means about 2.8 V peak-peak. However pro audio sound cards can handle (and produce) nearly 20 V peak to peak.
@@AndreasSpiess Its cool man, you're bringing me up to speed! Subbed and enjoying your content and delivery very very much. Great explanations, graphics, and editing btw. Cheers! ;-)
How cool is that? Well now I know I didn't have to suffer building my own DSO. A GeForce gaming card was there all along. Almost Russian like, You want radio get parts from tractor.
back around Windows-95 in some astronomy magazine. Someone taken a PC and a 8.5" LDA photo-sensor from a simple document scanner. Then relocating the sensor to point at the night sky and with a little sensor on/off timer was able to scan the stars and moon as the earth rotated giving a basic image for very little money. 🌠🌛 another neat project 🪐 thanks 🤩
I use to work with sound cards as spectrum analyzer, since about 13 or 15 yrs ago, analysing engine knock sensor signals, while I tune the ignition advance time. Because the frequency of engine knock depends only on the piston bore diameter, and it's perfectly human audible, sound cards are perfect to use. And I can measure two channels at same time: engine phase and the knock sensor. So I can detect what's the real knock, in what cylinder(s) from some other noises like a bad adjusted valves, huge piston clearances and other engine noises. The other way is to use a simple audio amp and listen the signal generated by the sensor. It's obvious the hard way. Very hard.
Yeah, about that same time I was tape recording my chainsaw and playing it back to Windows 98 through Sound Recorder, then analyzing and displaying using Quick Basic. Looked just like a scope with 2 cursors for analysis. Very revealing I tell you. Also recorded firecrackers. It's not what you'd expect. :)
These are very good examples of how this technology can be used. Thank you for mentioning them!
Interesting mmm
@Chiavaloni Now you win the right to made us a video to show us this interesting howto !!! 😁
@@antoninperbosc1532 wow... I used to do this more then a decade ago. :P To do something like this now, and make a video, I will need a car/engine with a programmable engine management system (Programmable ECU) with a properly knock sensor, perhaps a good audio pre-amp, an adaptor cable (from the knock sensor to the mic/pre-amp input) and of course, the notebook with a sound card. And a car/engine dynamometer... If you are curious about the engine noises, I found a video from HPA ( ruclips.net/video/66okwgg6Rrw/видео.html ). I didn't found any kind of video with the same things that I used to do. Sorry. :(
How about hacking a memory stick with a resistor ladder to grab analog data at ddr2,3 rate? Just increment the address bits and do a read of the data pins which are hooked to a ladder. Then display by changing the rw pin.
You can try that. Probably a lot of work...
I'm gonna use my phone as an oscilloscope
I hope you will not destroy it ;-)
Nice video and brings up some memories of the past. Back in 1997 I used a PC sound card to decode the DCC track signal of my model railroad and display the commands that are coming along the track in real time. The DCC signal is a pulse width modulated square wave with a maximum bit rate of about 16kbps, so it was quite easy to decode with 44.kHz sampling. As interface I used a resistor in each wire to the track and two antiparallel diodes to limit the input voltage on the microphone input. Software was written in Borland Pascal for Windows, running on a 486 with Windows 3.1. Tempi passati ;-)
turbo pascal
@@sookmaideek not necessarily. Borland Turbo Pascal and Borland Pascal are different, where Borland Pascal was more high end, and contained more libraries out of the box.
@@thorbjrnhellehaven5766 turbo better because faster and turbo
You were very early using this technology! And you stayed with the model railroads. Now with much more sophisticated gear, of course ;-)
Borland Pascal for Window, yes those were the days, ... ~1984
the "loss" of your low-pass filter only comes from the limited low input impedance of your sound card. You can easily check it by using a filter with 1 kΩ and 160 nF. A passive RC-filter is lossless in the passband if driving a high-impedance input.
That or a opamp buffer as medium between the sound card and the RC filter
I agree with both statements.
so puting an AOP in follower with hight impedance to "isolate" the DUT could avoid distorsion ?
@@antoninperbosc1532 distortion is not related to the dampening of the signal. The RC filter is linear for a sine wave of constant frequency, even if it is connected to a low impedance input and does not cause distortion. Distortion is generally caused by non-linearities in an amplifier. Other problems are caused by the frequency dependence of the phase shift if one considers a mix of incoming frequencies like voice or music.
I use a similar software (soundcard oscilloscope), its very easy and gives real oscilloscope like interface. I also use two silicon diodes (one forward, one reverse biased) in parallel to the potentiometer on the input signal and ground wire to bypass any AC voltage greater than 700 mV. It saves the soundcard from any accidental over voltage when the potentiometer is not correctly set.
Good idea with the diodes. And I placed a link to the Soundcard Oscilloscope SW. Thank you!
Did the same .
But added a 2 pole 6 way switch.
It has a though , 50 R , 8 R , 600 R dummy load , a diode for AM demod , rf signal tracing & rectified output for a DVM .
Signal tracing can be via the pc speakers if necessary & the microphone boost can up the gain .
That's af or rf demodulated signal tracing .
( Noise can be reduced by subtracting the unused channel #2 from #1 ) .
I almost fitted a calibrated RF wave absorption & notch filter .
But the box wasn't big enough 🤦♂️
Note this is not isolated so not for high voltage or tube work !
Yet another useful AND interesting video. Once again, you've saved me a week of research :-) Thank You!
Glad you liked the video!
@@AndreasSpiess Same here. I might not use this info today. But now I know where to look when I *do* need the info. I do need to do some audio experimenting later. Thank you.
It is pretty easy to bypass the capacitor near the input or output jack on the soundcard to be able to input/output DC signals as well. I've done this both for using audio input as an oscilloscope, and for using the output as a signal generator for a laser galvanometer and it worked great for both.
Good to know. Thank you for the tip!
The 'no-DC' issue I did not anticipate. Is there a technical reason why the soundcard is AC-coupled (e.g. related to it having a 18-20 bit ADC)?
@@iforth64 : AC coupling for soundcards (and a fair variety of other things) is the norm, because it reduces the chances both of ground loops, and of safety hazards.
@@iforth64 DC means V+ and Vzero with V+ will push the speaker forward then Vzero will return the speaker back to natural state. Then AC means V- will pull the speaker backward deeper and quicker to compare Vzero.
@@iforth64 In an amplifier you do not want to amplifie DC offsets since at high levels they will push the amplified signals to one of the powerrails. If that happens the peaks of the signals are cut off which causes extreme high distortion. You can not control if the applied input signal has a DC offset. But with a capacitor in series of the input you can block any DC offset preventing this problem.
Nicely done! I figured that this was possible back in the late 1990's but never found the time to explore using a sound card as an oscilloscope. It's great that other folks had the same idea but actually put in the time to bring it to reality.
Indeed, soundcards are high performance devices which are also used by software defined radios, for example. Just different software...
Nice one Andreas. If you learn something (which we may already know) it's (still) _your great way of presentation_ that makes it fun ... *Love That* 😘👍
Thank you for your kind words!
I just remembered this one !
If the software has a audio analyser but you can't inject a sweeping signal .
Try a simple wight noise generator injected into the amp .
You will see the passband response on the analyser .
It has limited uses with RF also , tune for maximum noise or work from a good audio stage into the radio / unit / DUT .
Like passing a 100 khz square wave ( & overtones ) through a radio receiver .
Old tricks we used when all we had was time , a box of scrap , war surplus & brass screws !
Using white noise as an input is a great possibility. Particularly with the new broadband SDR receivers. You immediately get the full frequency response.
A deep dive into existing 'stuff' right under my nose; presented fully as always. Amazing what free software is 'out there' as you show. A very helpful video. I, of course, have a wonderful oscilloscope but didn't even think I had one in my PC. Very enlightening.
Glad you liked the content. Not a replacement for your oscilloscope, but maybe an estension...
If you build the "Artabox" for REW you can use it as very accurate LCR Meter.
Good to know. Thanks!
Thank you Andreas. And thank you for not following the "Make a stupid shocked face thumbnail" trend on You tube!
You are welcome!
I love how the sweep test just randomly interferes with the talking 😂
That one was easy...
Easiest thing to experiment with - is to connect transparent diode to line input.
Now you will be able to receive IR signals from remote controls.
If you write corresponding software of course :)
Good idea. Most IR remote signals are around 38kHz. So you probably have to use a high sampling rate, I think.
@@AndreasSpiess it is possible with low sample rate too.
I tried that. The soundcard input impedance is extremely low, it doesn't work.
Buy an inexpensive PC oscilloscope. Considering the outrageous price of video cards nowadays, a PC oscilloscope is a fraction of the price.
Also a good choice, particularly if input impedance is important to you.
".. all newer pcs have .." ... Intel skipped that class, my 11th gen Intel NUC doesn't even have a sound card! (relies on display over usb-c with audio, which they didnt:/)
Interesting. I did not know...
My lab cat is very fascinated by todays presentation because of all those moving cursors :-)
I can imagine that this is interesting for a cat ;-)
a small warning before the sweeptest would have been nice
He even talks while the sweep test lmao
Sorry for that!
i would Never try this chit on your expensive gamming PC EVER Poof 1 mistake $3k
Just use an old spare PC use a $100 pc found in a dumpster ha!
Very good idea!
Those shiny mirror screens on laptops are horrendous.
I agree.
Some time ago, before I got a scope, I considered using one of my audio interfaces as a scope. The 24-bit resolution on the converters are exquisite, but the sample rate leaves much to be desired. My scope is 1 GSa/s, whereas my interface maxes at 192 kHz. (But I can measure up to 10 channels! Or if I use multiple interfaces, 34 channels at 96 kHz.) I think I did actually try this at one point, but I seem to remember there was a huge DC offset, and I was worried I'd blown something. They all have input caps, but... still scary. Never again. (Fortunately, they're all good.)
After watching the video in full, I take back my "never again" comment. I can see how valuable it'll be in the audio domain. As long as I know I won't cause problems for myself. Idiot-check with the scope or DMM, then detailed measurements with REW. 😁
Indeed they should not be compared 1:1. Both have advantages and disadvantages.
AUwww ,
That sweep ,my right ear is bleeding now.😨😨
Please warn headphone users .😂😂.
Sorry for that!
you can receive DCF77 and other long wave time signals with a soundcard and a long wire
Or Russian military signals at 18.1kHz.
Interesting. I never tried it.
man for the love of god, don't do the 20hz-20khz sweep without a warning.
Sorry for that!
Wonderful! That's going to be great stuff for experiments with my 12 yo in the workshop 👍
I hope she/he will like it. Good it is audio where kids probably can relate because they hear the sound.
There's alot you can do with a PC but it is not realtime due to latencies in the operating system and USB protocol. This doesn't stop you from doing non-realtime (record and analyse) however for an oscilloscope realtime is needed for trigging. Only reason you may not want to use a PC is isolation - tube amps with hundreds of volts and PC are not a good combination without specialist hardware. A differential probe helps and could be used with a sound card - isolating and being safe.
The only down side to a PC sound card is the lack of control over the processing - some operating systems perform conversion, and apply human ear perception equalisation etc. MacOS used to be a pain for that, the later operating system allows the developer better options to prevent this.
I wrote a Bode plot AWG for my 1104x-e and currently writing a high resolution spectrum analyser (1Mpt and 1MSPS). You may want to use flattop filtering on the FFT as this provides the best measurement value.
Triggering does not need realtime. Just write the data into a ring buffer and evaluate any trigger condition at your time. This also enables pre-trigger, where you see some data leading to the trigger event.
What realtime is fast enough for you?
It is easy to get ~100ms latency. ~10ms is harder, but possible too. ~1ms looks like maximum of what PC + sound card can achieve.
@
Nick K: I agree on the limitations you mention. Particularly I would not use it with tube amplifiers ;-) Fortunately, they are rare these days.
That's why you don't use WaveRT/DirectSound Drivers on Windows, or CoreAudio on MacOS. You have to use audio drivers which bypass any OS/Driver processing, putting the audio codec in a sort of "promiscuous mode". I don't know how that can be done in MacOS, but in Windows you use ASIO drivers for that. ASIO4ALL project provides a free of charge ASIO driver which works with the common Realtek codecs which don't provide ASIO by default.
RIP headphone users @ 4:22. Even on the speaker on my laptop it was really loud.
Sorry for that!
Thanks for this video! I just look at diy pre-amplifier for electric guitar. With your recommendation I can verify frequency response of pre -amplifier, when it is ready. In the meanwhile, do you have experience with external usb oscilloscopes, is there a good one, not very expensive, possibly from aliexpress?
I only own the bench oscilloscope, so I am not a big help. Usually, you get what you pay for if you go with the better-known oscilloscope brands: The more you pay the better the specs.
The sine sweep was painful with in-ear headphones! Please make sure to tune the noiselevels better
Sorry for that!
I have been using the free DAQARTA demo program which allows unlimited use of its oscilloscope and a few other functions, while its signal generator is limited to 30 times or 30 days use after which you need to purchase it or re-install the program for another 30 times/days of fully functioning demo, which includes its most important tool to me: an LCR/ESR meter which can measure as low as 1mΩ resistance, 1pF to at least 10,000uF and less than a uH resolution (I think as low as 1nH), though such low measurements are filled with noise, depending on the soundcard's S/N ratio.
I use an Audiophile 2496 soundcard, so the noise is at least 10 times lower than on the standard cards.
I did not know that they could do such precise measurements!
@@AndreasSpiess Even with my 2496 sound card, actual usable resolution for inductivity is 1uH, with 0.1uH digit changing all the time and you sort of see which number is the most frequent. Below that, numbers are changing too much to be useful.
All that is needed besides soundcard (and a cable) is a reference resistor and probes, and the ability to short out the reference resistor when calibrating the software.
I plan to add an external output amplifier so that I can use a lower value REF resistor (improves S/N ratio) and a pre-amp at the probe (also to improve S/N ratio).
One channel is used as an output, and 2 channels are used as an input - one takes signal before and the other after the REF resistor, comparing their phase shift and relative values to automatically give out results as capacitance or inductance, along with ESR and DF for caps and resistance and Q factor for inductors.
Well done again Andreas! I was using something similar few years ago and not just on PC, but also using a tablet! It was working well, for what it is and mainly I had fun with it and so did my friends, for whom I made the cables for. Also old phones can be used to play with this kind of stuff, since the phone is old and not in use! I'm a Tracfone user so every year I get a new phone and my wife also, so at least 2 phones per year are dedicated for all kinds of projects, including Mooshimeter, Pokit Meter and few of my regular meters that have Bluetooth built in for remote measuring. Thank you again Andreas!
You are right, Smartphones contain a lot of good technology and can be used also when they are old.
I was duing some experiments with audio signals and misusing a sound card. I was using just an ordinary integrated Realtek HD Audio. I've discovered that the sound chip is doing some funny stuff to the signal. Namely it seems it has some kind of autogain, which can't be controlled or turned off from the software. Also laptops usually have only a microphone input, which is more difficult to use for recording arbitrary audio signals. So it's a good idea to carefully test your equipment, if it's suitable for the task.
That's true, especially for laptops that have limited I/O and usually combine headphone and mic together. The easiest and less risky way is to use an external USB audio adapter with proper line in/out. Worse case you kill the adapter but keep you computer safe.
Using an external sound card is what I recommended, too. They are no more very expensive.
But I agree, there is always a possibility that the signal is distorted by the PC.
I'll stick with my scope for the measurements but having a programmable signal generatr could be extremely useful
I think the point is that if you don't need it for high precision and rarely, it's probably good enough. If you're doing anything that requires serious precision, you'd probably want to just buy a quality bit of kit.
get an analog electric analog computer. Best SG you will ever get.
@Frank: I agree it is not a replacement for an oscilloscope.
ruclips.net/video/SYBkL4Or2To/видео.html
Go to this link... You will find more close waveform on pc as you use Arduino as DSO
you’re channel is a hidden gem 💎👍
I would hope it becomes a little less "Hidden" ;-)
Thank you!
I've used REW and a Dayton Audio UMM-6 USB calibration microphone to set up a couple church sound systems. That software is crazy powerful -- I've seen commercial solutions that aren't as comprehensive. Anyone interested in playing with sound systems, especially measuring speaker response, would do well with this combination. 👍️
Thank you for sharing your experience. So you understand much more about all the measurements possible with REW...
@@AndreasSpiess Goodness... if it falls under the Acoustic domain, it's probably measurable. I won't claim to know everything it's capable of, though. 😁
Very interesting and useful video Andreas! 😄
Thanks! 😃
Excellent video and a very good introduction to sound cards and their benefits to signal processing. It's also a trip down memory lane... Many years ago (Pentium 3 and 4 era) I used a sound card to decode/encode tone signals in combination with radio equipment (CTCSS, SelCall tone sets like EEA, ZVEI I etc...). What a wonderfull time...
We still use the sound cards to decode signals in amateur radio. This is a cheap and high-quality procedure.
I did not know that this trend started already long-time ago.
@@AndreasSpiess The encode/decode with soundcard project was my thesis project. I started with radio communication for my job in the early 90-ties. In that era our relay stations were connected with M1020 orM1040. I started a project (which got cancelled...) to interface radio's with ethernet, today known as RIPS (Radio over IP Streaming) to get rid of the expensive leased lines. A little later... the era of Tetra pushed back all the older equipment and projects to maintain/improve the analog network. I miss this older period somehow... I guess it's a little nostalgia.
No one here seems to have mentioned USB isolators yet. Isolation on the USB side would seem a good general purpose approach that would be transferable between lots of use-cases where you want your precious PC connected to a bench of not-yet-proven project. A USB isolator must be a fairly tractable thing to implement, but I've done a load of searching on Amazon and not found anything that definitively performs this task. I'm sure they must exist and I'm just failing to find them. Thoughts ?
A good idea. I added a link in the description.
White gloves and the tophat always make your videos feel special. It's like you're about to show us diamonds and artifacts. So classy!
Also thank you for this. I've needed a way to analyze signals without a scope.
Never looked at it this way. The hat and the gloves just happened...
I have heard, but not tried it myself, that it is POSSIBLE to measure DC, if you short-circuit the input capacitors ...
You can try that and it should work. I certainly will not do it. Too complicated...
Unfortunately very few modern computers and external sound cards have stereo line input, a mono mic is predominant, which makes it difficult to input signals. My oldish PC is good in this respect.
Two other free softwares are
Digilent Waveforms (front end for their instruments but includes a sound card option)
Soundcard Oscilloscope by Christian Zeitnitz - a bit dated interface but does the job reliably
You should look at more expensive sound cards. I have a thing sitting beside me with stereo mic inputs, and 8 channels of balanced line inputs and 8 channels of balanced line outputs. Of course it cost me a few hundred bucks.
@@lwilton ... which totally defeats the point of the original video
@@alexandern8671 No it doesn't. The title of the video isn't "make a scope for free", it is "use your sound card as a scope".
A $300 sound adapter is still a tenth the cost of a $3000 scope, which is about the minimum these days for a decent scope. And the scope won't have the gain dynamic range and noise floor of the sound card, nor is it likely to have FFT or spectrum analyzer capabilities, and may not have a way to record what it sees on the screen. And you can get that $300 sound card for maybe half that used on eBay. I've got both a scope and a cheap PC with a good sound adapter, and I use both. They have different strengths.
@@lwilton Agree with your point regarding the title of the video.
However I do not think someone with a budget of $300 should invest in a sound card for the purpose of scoping some signals. Andreas has discussed the downsides - no DC, limited frequency range. If one has such a card already like you then of course it is nice to repurpose it though. I can think of some niche applications where the increased vertical resolution could make a big difference but they are hardly the mainstream. Can you please give some common use cases that would benefit from increased vertical resolution?
@AlexanderN: Thank you for the links to the software packages.
Thanks for your video! I think this is a great idea!
I just wanted to say, that maybe you can use an optocoupler between the signal and the sound card's input. This would protect the sound card in a better way than the potentiometer.
For high voltage digital signals it is good idea for sure.
But I doubt that optocoupler will preserve shape of more precise signal.
Opto-isolators usually introduce a lot of non-linearities (as
sdjhgfkshf mentioned). So this would disturb the signal. Maybe it would be better to use an external soundcard and a USB insulator.
@@AndreasSpiess : Yeah, I got an external USB soundcard for this very purpose (around $4, so cheap), though not a USB isolator.
I actually did this years ago with my little netbook when I was putting a new stereo in my mum's car. I don't remember the programs I used but it was very handy to identify which wires went to which speakers.
Cool idea to use it for such a project!
This week ive learned about how SDR works with your dual channel sound card thanks for this video!
Very GOOD, I am an audio projects addicted, I built my own Stereos and pre-amps. I will try this tool. Thanks
You will love it, I am sure!
Great Stuff ! Never have thought that you can use a soundcard for this, also not aware for the free software programs for this, thanks !
You are welcome!
Very interesty video, great work
Glad you enjoyed it!
@13:38 regarding disadvantage #4 that sound cards don't measure DC: For most soundcards that is true. However some soundcards (such as the MOTU 624) have DC-coupled analog outputs, meaning that those outputs can provide DC (and low frequency) output. Though I don't know if there are soundcards with DC-coupled inputs.
Thank you for the info. Another viewer also wrote that he removed/bridged the input capacitors on a "normal" Soundcard
@@AndreasSpiess I was going to suggest that. ADCs are mostly DC-sampling devices and most sound-cards should be able to sample DC by shorting the input caps, unless high-pass filtering was done in the feedback or the DSP.
For maybe 20 dollars you should be able to get an audio-quality stereo I2S ADC and DAC, feed them through fast optocouplers, and send that data to a USB MCU that can send it to your computer. Arguably there are some computers that will take digital audio signals like SPIDF and some ADC/DACs that can produce it such that you don’t even need the MCU. Then I’d have a 6+ resistor range switch followed by clipping diodes for the input, and a couple of different gain amplifier settings for the output. Maybe an input buffer amplifier running on some larger voltage rails, for input impedance purposes.
I agree that this can be done. But you forgot an important ingredient: The software which also would have to be written.
@@AndreasSpiess from what I hear the Arduino Pro Micro has a fair bit of code written for it out there, acting like a sound card is almost certainly one of those. If that bitrate isn’t fast enough then the same should apply to the STM32F103, though they’re a little tougher to get programmed.
Another option is using an FT232 and SPI ADCs/DACs, not sure how much programming they need, but I’d guess it would be less than the STM32 and still give you full speed USB2.0.
For USB3.0 purposes there’s the Cypress FX3, but from what I hear that’s a pain to program and it’s only really necessary for really high bitrates or SDR territory.
i keep wondering if the rtl chips (dvb dongles ) could be used for similar approach
These are SDR radios, work for different frequencies and need different software. But the principle is the same: Use the power of the PC to reduce hardware cost.
If you get a professional sound device (as opposed to an Ali-Express "professional(tm)" sound thing) you should be able to handle up to about 24Vpp of both input and output levels without distortion. Obviously if you are working with unknown-level signals it would be a good idea to build a +-15V clipper for the input signals.
That is interesting! After this comment I looked up the specs of my Focusrite and it has a max input of 22dBu which s 27Vp-p at minimum gain.
@@AndreasSpiess The Scarlett qualifies as a professional device. Basically if it has an XLR jack and 6mm TRS jacks, it is likely to be +20dBu or better. It should be able to output similar levels into 600 ohms. Pretty much all of these devices run the internal opamps from +-15V, so subtract about 6V from that to get the max direct input level or max output level.
I wonder if we can use a soundcard with a down converter or upconverter as an SDR?
Many SDRs already use the soundcards... So it is possible
I think Sdr radio has been using this for a while, it’s very clever
You are right, many SDR receivers use the soundcards for the I and Q signals.
I already have a pretty good scope, but I think I'll stick to physical circuits when it comes to signal generators. Having said that though, these programs do look usefull.
I stick to my instruments, too. But not for audio analysis. Here, this PC software is much easier to use...
Does anyone have more details on how to make the connnectors?
Super cool! Very interesting in this topic. I've search for these setups years early, however, I did not able to fully setup a set of software and hardware in my computer. Thank you for sharing this!
Glad it was helpful!
While audio card oscilloscope is handy, there's some caveats; the processors and / or ADCs, and DACs used by most sound cards tended to be slow so 48 kilohertzs bandwidth is usable at most, if that. However, it's cheaper to do it and get done quickly.
And I strongly recommend that the line or microphone inputs be protected - the same way you would do when putting together a few more extra coaxial oscilloscope leads for the most expensive kit.
Thank you for the additional info!
The Java sound device not being able to generate beyond 22 kHz points to it internally capping at CD sample quality, 44.1 kHz. Per the Nyquist-Shannon sampling theorem, the highest reproducible frequency is half the sampling rate used.
I think that is right.
I don't even trust to connect a USB oscilloscope to my computer, my computer is way too valuable to risk damaging it... I would NEVER do something like this and if your computer is valuable to you I highly recommend you NOT TO DO THIS. We all make mistakes so it's a matter of time, not a matter if it would happen to you to make a fatal mistake and destroy your computer.
I agree to be cautious. But USB oscilloscopes should have a protection for your PC (at least this is what I hope).
Dear Andreas, you are one of my favorites.
You drove my cats crazy with the sweep sample🤬. Still love your channel... and the accent bdw.
Sorry for that!
I find it annoying that people refer to the two dollar chip that comes on the motherboard as a 'sound card'. It is not a card, and it cannot be removed or replaced like a card. No one refers to CPU video as a 'video card'. External boxes are Audio Interfaces - and also Not Cards! So why? Lazy speech, as usual.
I agree. But as long as we know what we mean it is ok for me...
Software defined radios also work with a pc soundcard
You are right. And all digital modes in HAM radio
I have tinkered with sound cards as oscilloscopes. I'd suggest connecting diodes in parallel to the 3.5mm mic input to clip their voltages to 0.7V to protect the sound card in case of input over voltage.
My sound card (SB Live!) survives even signals with 4 diodes protection (twice your level).
I suspect that it may be capable to use even higher voltages.
It is well possible that some cards support higher levels. My Focusrite seems to support 25Vpp. But only at the lowest gain...
Good idea.
Very good explanation...he gave a professional class...thanks and greetings from Paraguay
Glad you liked the video!
Those ADC have a DC filter capacitor now I can't read DC voltages better stick with Arduino 😢
Yes, they cannot read DC.
Generally not a great idea, I can immagine some noobs blowing their cards. Also soundcards, even high end ones, have piss poor bandwidth.
I agree that noobs can do all sorts of things. Fortunately, not many of them watch this channel ;-)
if i have FM transmitter circuit can this pc oscilioscope works and detect the frequince or test if transmitter works like the original one
I do not think so because these frequencies are much higher (usually around 100MHz)
I have a 32 bit 392khz soundcard, wonder how well it would perform......
It would perform very well, I assume ;-)
Great video. I though we had to put optocoupler to protect the soundcard?
I know many people use Audacity software as well
Optocouplers are not linear and would not help in this situation because they would disturb the signal. You can use an isolated USB connector to connect an external soundcard and it would work.
very good info, I would like to get into this more. New Sub /cheers ScrapBongo Liked
Welcome aboard the channel!
Oh no, yet another squirrel/shinney object to distract me. I like it, wish it could do DC as well.
We misuse it, so we cannot choose, I fear.
Hello nice video! We need a new software becouse arta will close now! Which one sustitute for arta?
This video is quite old. I did not check for an alternative :-(
too long, to boring, too academic, little or no use in real life, you re just the kind of puppy that likes to hear himself talk, i bet your wife plans some divorce
Thank you for your feedback and good advice!
Is there any cheap way to use this for 0-5V Digital Signals? The Frequency Domain Analysis is interesting but of little use for the average DIY guy I think ...
At 13:35 he mentions that DC and digital devices cannot be used/ measured - only AC.
@@Texas1FlyBoy Even low frequency signals couldn't be used with voltage dividers to get the inputs in the 1V Range?
@@bbogdanmircea I just wrote a comment about the same topic. I can imagine that you can read signals but they might not be stable, but maybe you can read voltage changes from high to low. I would love to know that
@@glumpfi I remember a long time ago I did just that and it was ok but you have to be careful.
Use Cypress FX2/FX3 for that.
Very good video. But how much voltage do you think a sound card could handle?
A typical consumer grade soundcard is about 1V rms, which means about 2.8 V peak-peak. However pro audio sound cards can handle (and produce) nearly 20 V peak to peak.
@@big_whopper Thanks.
Spend $20 and buy a TI ADS1262 with 24bit and 32bit ADC.
If you get software to use it, a GND idea.
as an earphone user, that sweep hurt :C
Have Opto-isolator or Photoresistor(light as wave carrier) the response speed inorder to limit the input voltage?
That is not easy because these opto-isolators introduce a lot of non-linearity. Better to use an external soundcard and use an USB isolator.
You can also use your soundcard to measure the thiele-small parameters of a speaker.
Good to know (I had to google "thiele-small parameters" ;-)
@@AndreasSpiess Interesting, hope we can see you talking about it.
Digilent’s Waveforms software is free and has a mode that connects to the PC sound card.
Thank you for the information!
I’m so new that was as clear as mud 🤪thanks anyways. I guess at some point I’ll understand what you said.
Good you stick to these videos. My videos are made for advanced viewers or for beginners with ambitions to get better ;-)
Really great video, like golden swiss cheese. Thanks for creating 😂
Glad you enjoyed it!
I could not understand anything. But one thing I can say you all are very very intelligent and gifted people
Thank you for watching, even if the content was not very understandable!
sir good afternoon waveform generator to laptop connecting steps please help me sir
I share my know-how in my videos and, unfortunately, cannot do consulting :-(
The sweep was unnecessarily loud compared to your speaking volume
Sorry for that!
Yeah that will be good to a few hundred kilohertz !! WOW !! maybe !!
No. Not more than 96kHz.
09:32
Walid Isaa💞
:-)
so we're looking at harmonics distortion something that i know of when it comes to sound design and Electronics
:-)
Not sure I understood how to connect a device. Do you connect to the two pins of the microphone jack?
Just connect the signal to one pin and ground
Not sure I understood how to connect a device. Do you connect to the two pins of the microphone jack?
One pin and ground
A very interesting video. I learned new things today. Thanks 👍
Glad you enjoyed it!
What an interesting idea! Just preparing to build a diy headphone amplifier, this could be very handy for testing and troubleshooting.
For sure you can test its frequency response and its distortion.
A good way for beginners to blow up their soundcard. 😋
Indeed!
Another excellent video. Thank you.
Glad you enjoyed it!
man i feel stupid
Sorry for that :-(
@@AndreasSpiess Its cool man, you're bringing me up to speed! Subbed and enjoying your content and delivery very very much. Great explanations, graphics, and editing btw. Cheers! ;-)
Very interesting video. I was using number of "PC scope" like programs, but about REW and Artalabs didn't know. Thank You Andreas.
You are welcome!
How cool is that? Well now I know I didn't have to suffer building my own DSO. A GeForce gaming card was there all along. Almost Russian like, You want radio get parts from tractor.
Indeed it is a very creative solution!
back around Windows-95 in some astronomy magazine. Someone taken a PC and a 8.5" LDA photo-sensor from a simple document scanner. Then relocating the sensor to point at the night sky and with a little sensor on/off timer was able to scan the stars and moon as the earth rotated giving a basic image for very little money. 🌠🌛 another neat project 🪐 thanks 🤩
Interesting project! It is always interesting to repurpose consumer HW because it usually has an extremely good price-performance ratio