The Opto Compressor - Fabio's What clone.
Optical compression generally provides a smooth and
syrupy control to the signal it is processing.
These two What clones (PDB's courtesy
of Fabio) are no exception.
Both featuring OEP transformer balanced inputs,
one unit uses standard ne5532's in the signal path.
This provides a clean and smooth compression
with enough gain to run an SM57, direct!
The other unit features the same input trannie, but
uses discrete melcor 1731 opamps instead.
The 1731's add a certain amount of crunch and grit,
and really can excel on bass guitar or snare sources.
Build Links :
Prodigy - Building the What Compressor
The DIY Pill - The Joe Cheap