Make Noise Optomix - Manual (Page 6)

OVERVIEW
The Optomix is a direct coupled, two channel low pass gate utilizing 4 vactrols to pro-vide simultaneous
voltage control over amplitude and frequency content of a signal. It is in essence, a VCFA (Voltage
Controlled Filter Amplifier). Additionally the Optomix offers a summing stage complete with an AUXiliary IN
allowing for the chaining of multiple units to create larger mixes (this also works well in combination with the
modDemix.
The DAMP parameter, unique to the Optomix, allows the artist to program the way the low pass gate
responds to a decaying control transient, such as and envelope signal generated by MATHS or a Gate
applied to the STRIKE INput (see below). DAMP is continuously variable from long, slow and ringing to
short, fast and muted.
The STRIKE INput, allows the artist to use a typical 8V Gate signal to trigger the LPG (Low Pass Gate)
circuit by “plucking” or “striking” the vactrol, thus allowing it to impart its magically slow response time upon
the amplitude of the signal being processed (this concept is also featured on the Make Noise DPO and
MMG). Combined with the DAMP parameter, STRIKE allows for the programming of percussive sounds
(sharp Attack w/ Voltage Controlled Decay) without the need for a voltage controlled envelope generator.
As a VCA, Optomix has a moderate attack response and slow decay response, meaning that it turns on
quickly, but takes a while to shut off, yielding a smooth natural sounding decay to almost any sound
processed dynamically. Folks have often de-scribed the sound as “ringing,” and while the circuit is not
technically ringing, that does describe many of the sounds possible when using a LPG such as the Optomix
to process complex signals generated through FM or Ring Modulation.
As a VCF it is a mild, nonresonant Low Pass circuit acting to gently reveal (or hide) the sharper edges of a
sound. This characteristic also adds to the “ringing” effect. As the amplitude of the sound decays, there is a
simultaneous loss in high frequency content that is similar to the natural loss of energy in idio and mem-
branophonic instruments.
PERSPECTIVE
The Optomix being a vactrol based circuit, will never have the speed or tight tolerances found in many other
VCA and VCF circuits. I would recommend that musicians desiring closely matched gain across multiple
channels of VCAs look elsewhere! If you seek to program extremely short sounds, clicks, pops and ticks, the
Optomix is not the best choice. What the Optomix does offer is extremely low noise and low distortion and a
smooth, natural sounding circuit.