PC Sound Card Oscilloscope, Generator, Spectrum Analyzer (FREE)

[danadak]

Quite capable instrument, free, for Audio type work.

https://www.roomeqwizard.com/

Be sure to protect sound card inputs and outputs, google "protect sound card inputs", many approaches and
circuits on web.


Regards, Dana.

 

[Ian Rogers]

I watched that last week.... Osc only does A/C ... But I was impressed with a 96Khz function generator..

 

[alec_t]

Years ago I measured the frequency response of a PC sound-card. It fell like a cliff below 20Hz and above 20kHz. Do all modern sound-cards have greater bandwidth?

 

[Nigel Goodwin]

Years ago I measured the frequency response of a PC sound-card. It fell like a cliff below 20Hz and above 20kHz. Do all modern sound-cards have greater bandwidth?

The clue is in the name 'sound' card

Filtered to cover the audio band, but I do remember mods for some sound cards to make it DC coupled for scope use.

 

[tvrgeek]

I have been using Zelscope for years. I'll check this one out. I use a Focusrite Scarlett IO box, so I still not DC coupled, better BW than the typical sound card. ( cap coupled so of course no DC)

Bought a Hantek USB scope, but 8 bits+/- 2 and only 20mV/div was not of much use for audio and power supply work. Bummer as a 12 bit with .5mV/div is well over what I am willing to pay.

 

[Nigel Goodwin]

8 bits should be plenty (better than 0.5% resolution), simply stick an opamp preamp in front to give yourself more gain.

 

[tvrgeek]

It was the +/- that was enough to give up.
I thought about a preamp. Build in nice over voltage protection. But I can buy another old Tektronix a lot cheaper. (Mine mystically both inputs went south. ) I don't have than many projects left, so I decided to move on.
If doing general digital work, it would have been a really slick tool. I remember "wayback" when the first digital storage came out. $50K and this one was $60!

 

[Nigel Goodwin]

It was the +/- that was enough to give up.
I thought about a preamp. Build in nice over voltage protection. But I can buy another old Tektronix a lot cheaper. (Mine mystically both inputs went south. ) I don't have than many projects left, so I decided to move on.
If doing general digital work, it would have been a really slick tool. I remember "wayback" when the first digital storage came out. $50K and this one was $60!

A suitable preamp would cost very little, google finds lots of examples:

Front End Turns PC Sound Card into High-Speed Sampling Oscilloscope | Analog Devices

A look at how limited bandwidth can be extended—for repetitive waveforms—by using a sampling front end ahead of the sound card inputs.

www.analog.com

Build a soundcard scope - Hobby electronic soldering and construction

How to build a soundcard scope using a handful of cheap components. Easy to build and giving amazing results for audio work.

www.bestsoldering.com

 

[tvrgeek]

Sure. If I wanted another project lots can be done. I don't. I have too many projects and only a few left require electronics. So, I will get by with what Zelscope, TrueRTA , Atra, Holm, RightMark, and REW can do. For $150 one can get a very good used Tektronix. Not worth it at this point.