We have just commissioned the build of a custom SSL style compressor for the studio

 Summary of Features:

-QUAD VCA Compression

- Main Board Features: Incorporated Turbo, 2x Super Sidechain, VU Bargraph Circuit for IN/OUT Levels, & true bypass w/ relays.  Main board is .5" wider, and 2.75" longer than the existing version.  Considering everything that has been added, this is a very modest increase.  As you can see in the pics, the board was designed to be installed sideways, and all onboard connectors are located on the board in relation to where they are being wired to (aka, shortest wire runs possible)

-Front panel - Thresh, Ratio, Attack, Release, HPF, Makeup, and Bargraph are all Board mounted on the control board.  Control Board connects to the main board via a 20 Pin Ribbon Cable, which is mounted on the backside of the board for easy routing.  Control board is the same width as the existing, about 3.5" longer.  The VU Bargraph has its own screw down power connector.  It is a mono VU meter, similar to the chameleon labs setup, and is switchable between L & R / In & OUT with 2 mini pushbuttons (Relay driven).  The benefit of this though, is you can monitor both Gain reduction and levels simultaneously now.  And the beauty of the Bargraph is: if you don't want it - IT SNAPS OFF!  And the bargraph driver circuitry on the main board is all within a silkcreened box so you simply don't install anything in that box if you don't want the feature.  

-High pass filter has Off/60/90/130/Tilt1/Tilt2.

-There is also a stereo external send/return, controlled with its own pushbutton, and is relay driven.  It's source driven, so you can send it either a mono signal or stereo for ducking, etc.

-Pot to adjust Turbo sidechain so both sidechains are equal.  Also another pot to calibrate ratios.  (Corrected, accidentally had written threshold here previously)

-Pushbutton to toggle between 10db GR or 20db GR.

-There is an additional release time added - 900mS.

-Resistor is present to adjust the threshold sensitivity if desired.