Tiptop Z-DSP - Manual (Page 7)

Analog Feedback.
I N S E R T C A R T R I D G E
Feedback is the process of taking an output and
applying it (“feeding” it) back into an input. This
technique is widely used in audio for a variety of
applications and is an especially strong tool in DSP
allowing samples to be re-processed.
The Z-DSP offers an open-loop-feedback architecture
which means that the user has the freedom to insert
other processing devices in the feedback loop.
For example, analog filters, frequency shifters, other
DSP processors, etc.
The Feedback Input contains a VCA that allows control
of the gain of the feedback loop. Given that this is a
VCA, you can control the gain from any voltage
source. The VCA is very responsive to control input
and can be swept up into the audio range for even
more wild feedback effects.
The feedback loop on the Z-DSP is hardwired internally
so with nothing plugged into the Feedback Input jack,
it is fed from the 100% wet Feedback Output. Turning
the Feedback Input knob clockwise will introduce more
signal back into the input of the channel. Inserting a
plug into the Feedback Input jack will break the loop.
The feedback section has a good amount of gain in it,
and will easily cause the module to self-oscillate. This
can result in some high frequency 'screeching' which
can harm your monitors. So take it easy on that gain
knob if you’re looking for smoother sounds.