[sdiy] Matrix FX module

[JH.]

As you might know, I've started a "Matrix FX" project last year. Basically a
blown-up EMS VCS3
format (patch matrix with 2k7 resistor pin mixing and output attenuators
instead of input attenuators
for each module), but with focus on sound processing.
(front panel here, for those who missed it:
http://www.oldcrows.net/~jhaible/matrix_fx/jh_matrix_fx_fpd_testprint.pdf)

I'll put the schematics online as I finish the modules, one by one.
First one contains an Inverter / Amplifier and a Serge-style wave folder.
Nothing overly special yet. The amplifier has a built-in vactrol limiter. I
plan to do this on many
modules, to allow wild movement of knobs without unintended overdrive. Some
of the modules
*will* allow overdrive, of course, such as the diode ladder filter, but
others will be protected.
The high gain setting allows heavy compression, so this limiting function
can also be used as an effect
of its own.
The "PB" numbers in the drawing refer to the Ghielmetti patchbay contacts.
The numbers in circles refer to the pins of sub D connectors. (I have
mounted sub D connectors
on the back side of the front panel, and the modules are just plugged into
these.)

http://www.oldcrows.net/~jhaible/matrix_fx/jh_matrix_fx_wavefolder_invamp_sch.pdf

JH.