DD-20 micro delays

[Michał Wiernowolski <mihalw@gmail.com>]

I've just discovered two interesting features of the DD-20
when the delay time is really short.
Perhaps this can also be applied to other delays.

[1] Self-oscillation
Set the delay time to 1ms, effect level and feedback to 100%.
You should hear the oscillation.
Then you may change the delay time to change the pitch.
This works in most modes and does not require any input signal!
(Disconnect the input to check this.)

The sound differs depending on the selected mode,
for example you may hear the modulators in the modulate mode.

Additionally,  if the time is set to 1ms, you may still hear
a change in the sound when turning the knob counter-clockwise,
despite the time remaining the same.

[2] Vocoder/Ring Modulation
In the reverse mode set the time to 15-25ms, effect level
to 100% (reverse signal only) and feedback slightly less
than 100%. When you input speech you will get a metallic
type of sound resembling vocoder or ring modulator.

It seems  the delay acts like a filter bank  amplifying all harmonics
of a given frequency, which depends on the actual delay time.
(Frequency analysis done with just my own ears;-)

You may turn the level below 100% to get more intelligible speech.

Michal