[sdiy] analog pitch shifter circuit?

[TIm Daugard]

From: "Paul Maddox"

> Maybe its me but,
> Couldn't you use good old fashioned hetrodyne techniques?
> no digital stuff involved (no huge amounts of memory).

I'm interested in the answers to this also . . .

My 2 cents: The problem with hetroydyne methods is they are only good for pure
sine. If you put a signal in with harmonics, and shift by 100 Hz, then the
harmonics are also shifted exactly 100 Hz. This ruins the harmonic relationship.

I.E.

1st - 250 Hz --- 350 Hz  --- 1st
2nd - 500 Hz --- 600 Hz --- 2nd should be 700 Hz
3rd - 750 Hz --- 850 Hz --- 3rd should be 1050 Hz

Hetrodyne is ring modulators. For small shifts it might be tollerable, for large
shifts it's not.

Tim Daugard
AG4GZ 30.4078N 86.6227W
http://home.sprintmail.com/~daugard/synth.htm

With roofers pounding on my roof finally.