"** Which does NOT qualify in any way, shape or form as a BENCH AUDIO GENERATOR suitable for day in day out, knock down drag out bench repair work on smelly, dirty, rusty old guitar amps."

Rusty ? you're lucky they got metal in them to rust. In my country it is hard to get metal, everything is plastic.

Anyway, what is so knock down drag out about it ? Are you going to do some sort of product testing and rating ? If you are talking guitar amps maybe instead of a low distortion generator you want a high distortion generator. they crave distortion in thoise things. In fact the crave the distortion by their favorite amp, at times the will build a seald box and mic the amp for a concert, or at least they used to. Really, all those big ass speakers and in the back is a little 25 watt Fender or some **** with THE ORIGINAL SPEAK, in a wood box with foam all over the sides, playing its guts out, but the microphone in the box feeds the big ass 2,000 watt amps outside.

Two basic things I do not see you needing for this applicatiion. you do not need anything over 20 kHz and you do not need low THD. The thing you probably could use is a calibrated output level to make sure the amp distorts correctly at a certain level input.

When you are lookng for bad outputs and **** like that, almost any signal will do. In fact I tesat regular audio amps sometimes just on a regualr input,like for FM or something. I just null the output and input on the scope and see what is left. Divide it up mathematically and you get a total distortion figure, which includes any phase shift induced error as well as any variations in the frequency response. It always reads worse than the THD or IM specs but if it is under 1 % you are doing good. At least you can be relatively sure that there is no malfunction in the amp.

We are not the Institute of High Fidelity, nor are we Julian Hirsch. That's something maybe to get across at Audiokarma. If you can REALLY hear the difference, there was something wrong. It is hard to tell 1 dB in frequency response and most people cannot hear 1 % distortion, but that varies. Studies done a long time ago indicated that people were much more tolerant of even order harmonic distortion than odd order. And the fact is that most speakers have so much THD that the spec is never published. It is a secret. A few do, but they are not among the cheap.

Anyway, as far as a generator just use resistors to divide it down and use the function genny. Float the DUT with an isolation transformer like the book says. That's the way you do it. However it will not get your money for nothing and your chicks for free.