measuring didtortion

[g4oep]

Hi - I have developed a very satisfactory technique for measuring audio distortion which might be of interest to readers. Visit this site -

http://g4oep.atspace.com/distortion/...distortion.htm

Andy G4OEP

[soongsc]

Dead link?

[Geek]

Works here

[soongsc]

still doesn't work here.

[tschrama]

Works for me... nice link, good info!

[davidsrsb]

Now working here at last.
Another way is to use two sources, which don't need spectacular performance, with a combiner and look at the intermodulation distortion.

[soongsc]

Originally posted by davidsrsb
Now working here at last.
Another way is to use two sources, which don't need spectacular performance, with a combiner and look at the intermodulation distortion.

How did you get the link to work?

[rdf]

Hi g4oep, I bypassed that software dozens of time in searches thinking it was just for ham ops, thanks for the head's up. (M-Audio user, -125 dB rez. Nice circuit though.)

[ingrast]

I've been using a similar setup for over a year, only I use a second sound card instead of a separate signal generator.

For 1 KHz THD I insert an active state-variable bandpass filter built with the very low distortion OPA 4134 OpAmp. With a Sound Blaster Audigy USB as signal aquisition device, measurement baseline is about 0.003% THD including generator, filter, and aquisition.

Bare unfiltered audio card quality is usually in the 0.1% - 0.03% range with luck.

FFT software is Spectra Lab but any appropiate software will do.

Rodolfo