RANDOM*SOURCE
1
Serge Audio Mixer
SERGE Audio Mixer
The Serge CV-PRO / MIXER pcb set by Random*Source can be built as either a (single or dual) Voltage Proces-
sor or as an active
Audio Mixer with 3 input chanels
, where the phase of the first input can be inverted for
phase cancellation effects. This document describes
only the Audio Mixer setup
.
As the Audio Mixer uses only one half of the main pcb, the
areas grayed out in the following picture should
be ignored
(left empty):
Please note:
•
Orientation of the main pcb:
power header is at the bottom
(when looking at the module up-
right, e.g. in a rack).
•
Circuit contains an interesting
diode-based limiter section
to prevent the added signals from
ugly clipping. This was presumably intended for use of the module as a CV processor. However,
it can also be used with audio signals - this leads so a fairly strong softening / rounding of the
resulting waveform that affects the sound similar to a slight wavefolding.:
For a “clean“ audio mixer leave the jumpers JP1 open to ignore the limiter section.
To experience the effect of the limiter section, install 2 jumpers at JP1 (parallel to the board, i.e.
connecting left and right pins in the photo above).
•
Use a nice (dual) op-amp for high fidelity, e.g. a Burr-Brown OPA2134 or Burr-Brown OPA2604.
