measuring amplifier distortion ?

[Tekko]

What is the easiest way to measure the THD of an amplifier ?

I know about RMAA but since its soundcard based, its numbers arent very accurate.

I saw in the citation 12 pdf by N Pass that an amp could measure itself but then all u get is a waveform which amplitude tell the amount of distortion but converting a voltage into % THD seem like a tedious and obscure task, and u need two channels to do it.

Any ideas ? Getting access to AP test gear would be golden but thats not gonna happen.

 

[mastermind88]

The easiest way is to measure the THD in design phase, but it requires accurate models for the simulator.
But if you want to measure the REAL THD, there are not very simple very accurate method for me, if you have not access at very expensive measurement system.

http://www.diyaudio.com/forums/tubes-valves/175802-audio-measurements-tube-amp-look-here.html

This is for me a good solution...

 

[h_a]

voltage into % THD seem like a tedious and obscure task

Man, that's how they all do it

Try the soundcard first, depending on hardware that works really well.

Have fun, Hannes