scope waveforms

[butwhatif]

Has any body ever documented any 'scope waveforms for the real thing, and/or for the clone designs? It's possible that the tone of an original could be achieved several different ways, not necessarily by a
circuit dupe. It's the tone/sound everybody's after right?, and although playing style is a large part of the pie, what does a for instance 1KZ sine wave look like thru the real thing's OD channel? I've built several 'clone'
amps in various platforms, most recently in a Boogie MkIII , and they all sound good, albeit different. It would be very interesting to me to see what kind of waveforms come out of various designs? Anybody?

[dave g]

I don't think you could tell too much just from looking at a clipped sine wave - they tend to look practically the same for all amplifiers. A spectrum analyzer will tell you a lot more, but even then it's not going to be incredibly valuable. A large part of the sound of a distorted amplifier is due to intermodulation distortion that happens when you've got a complex superposition of waves coming in as your input signal (i.e., from a guitar), and there's no real easy way to do nonlinear analysis of amplifiers in such cases.

Bottom line, use your ears

[butwhatif]

I guess I've just developed an ability over many years of reading a scope trace with a given input. There's a lot of information in a clipped waveform, things like, is it symmetrical, is there a presence boost, is one side tilted, is there a narrow or wide cut (Q) in a mid control, is the treble side squared or round--is there ringing, on and on. It would be nice to have some documentation of the waveform in a non HRM real thing-I've never seen this info in years of looking on the web-

[dave g]

You're absolutely right, you can tell a lot about what's going on, but not nearly enough to build an amplifier from.

[butwhatif]

When you put a Marshall amp on the bench, and put a signal thru it, everyone knows what the scope traces look like. Every Fender, whether tweed, BF, has it's own fingerprint. Same for efx pedals, I've seen too many pedals with 'Dumble Tone' that don't come close. It'd be nice to have a few 'bench' examples, rather than this or that guitar played this or that way, recorded with this or that mic.