[sdiy] non-gain distortions

[Mike]

From: "mike ruberto"

> besides the usual ring/amplitude modulation, bit reduction and
> waveshaping circuits, what are some other neat tricks for creating
> distortion that don't involve high gain?
>
Non - linear circuits in general like:
diode shapers/function generators - think lateral, her are some wierd and
wonderful diodes out here. I once got a good result with an old automotive
copper-oxide or selenium rectifier
deliberately mis-biased transistors/FET's
op amps with non linear feedback.

You can do some neat tricks with a poor mans take on a saturable reactor -
putting the signal through one winding of an audio transformer, and putting
a variable DC bias through the other.

A bulb 'baretter' analogue - like a small power amp feeding the signal
trough a 'loaded' small low current filament lamp. Pick the signal up across
the load, or use a small stranformer as the load and get jthe signal from
the secondary.

Signal through a not very linear optocoupler.

Digital dstort, using and A->D feeding the address lines of a RAM or ROM,
output data feeding a D->A, The RAM/ROM content determine the output, if
address contains it's own value, output is linear, if you divide the data
into bands, some variants are called Bitcrushing.

Hope this helps, for a start - do you want exotic, or cheap and simple?

Mike