What alternatives to oscilloscope?

[slav]

Hi
As in the title , what are other alternatives to oscilloscope when it comes to tube amplifier measurement? I have couple laptops on hand , both have integrated sound cards , is it possible to use them in connection with software to build inexpensive measuring (analyzing ) tool?

 

[Minion]

Ive never used one but a quick google search came up with these ....

Soundcard Scope

PicoScope Oscilloscope Software - the standard in PC Oscilloscope software

Real-time plot. Software oscilloscope graphical user interface DLL.


Cheers

 

[nigelwright7557]

I would be wary of connecting anything with mains on it to my pc.

You can pick up a cheap second hand scope for £50.

Got to be cheaper than a new pc !

 

[dangus]

I'd want an outboard ADC with optical S/PDIF to the sound card. ELV has an attractive yet inexpensive one. 24-Bit-Audio-A/D-Wandler AAD 24, Komplettbausatz | ELV-Elektronik Too bad shipping to North America triples the price or I would have ordered one already. (There is or was a cheapish ADC or "Digital Converter" ADV-2000. 16/44, optical and coax output, not an impressive ADC chip. Probably just fine for 'scope use if the bandwidth limit isn't an issue.) ELV also has an S/PDIF DAC; get one of those and you can use the PC as an audio analyzer without blowing it up.

 

[pby]

It would be dangerous to use your sound card to make measurements considering you're dealing with high voltages. The sound card input is designed to take line level or microphone level input and the input impedance is low compared to an oscilloscope. This would have a significant effect on high frequency measurements.
Not to mention it would be very difficult to get any meaningful measurements without proper calibration.
Another limiting factor would be the sample rate, most scopes are able to sample in the MHz range, this would allow you to pick up fast transient responses that wouldn't be picked up by high end sound cards.

To sum this up, sound cards are not designed for measurement even if you had the correct software. I suggest you look for a second hand scope. You can probably find one that's suitable for less than the cost of a sound card and software option.