Dock-6 VCA stereo mixer for Eurorack

The Dock6 VCA Eurorack Mixer.

A six input to stereo output mixer for ‘Eurorack’. Each channel is VCA based affording a fantastic sounding signal path.

Each VCA channel features :
  • 2 CV inputs with input level control
  • An Initial Gain Control
  • A Mute Switch with bi-colour LED Red: Muted / Green: On
  • A Large PAN control
  • Signal Indicator: The LED on the PAN control indicates the signal at the input.
The CV control also incorporates a useful buffering system: 
  • If a CV is connected to the top channel’s CVA input then this CV is electronically buffered to the remaining 5 channel’s CVA inputs.
  • Plugging a CV into the top channel’s CVB input will result in a buffered copy being sent to the other 5 channels CVB input.  This way you can control all channels with 1 CV line.
  • Each channel can have its own CVA and CVB controls as plugging in to channels 2- 6 CV inputs will override the buffered inputs.
Also included in the design is a three colour LED Stereo master indicator.
The design philosophy for this mixer was to utilise the THAT 2162 2x Blackmer VCA IC’s  which are similar to that used in the SSL bus compressor to control Volume and Pan for a single channel.  The output from the Blackmer VCA’s are a Current Source thus ideal for hi-quality stereo mixing.

A 4 layer PCB construction was used.

Soldering of the SMT was done in a reflow oven whilst sockets an pots are traditionally soldered.
Specifications:
Width 45HP (228mm)
Height 128.5mm
Depth (with the IDC power connected but without the extra cable relief) 30mm
Requires +/-12v to operate
Current Draw Approx 400ma