[sdiy] Delays: how?

[Seb Francis]

Or how about a nice low-tech analog solution?

Old reel to reel tape deck (I'm sure you can pick one up pretty easily), re-fitted with a variable speed motor, and a continuous loop of tape.  Vary the tape speed for the delay time, vary the erase head current for the feedback control.

It might be a bit noisy, but I bet it will sound good as you modulate the tape speed.

Seb




MED wrote:

>         Okay, the BBD source seems to have dried up (along with the whole
> "sounding horrible") and this raises the question: what now?
> I want to make a delay with a decent time (something like 1 second).
> Feedback should be adjustable from same level (feeding back until
> hard-clipping catches it) to silent. Preferable would be control over
> the feedback loop, like an effects chain (pitch shifting craziness, et
> cetera)
> I have the feeling that a modern-component delay will be a
> some-decent-bit-number ADC into a LOT of shift registers (same number of
> lines as the resolution of the ADC/DAC, times however many are needed
> for the delay time) into a DAC. Is there a better technique? Preferably
> something simpler?
>
> Should I just try to make a tape echo? How are *they* done? MM doesn't
> have any schematics for the rolands, just vague descriptions that whet
> one's appetite.
>
> -MED