User Manual
OVERVIEW
Quadratt is a four channel active/buffered attenuverter and summing mixer. Each channel has a
knob, which can function as a unipolar attenuator or a bipolar attenuverter, depending on the setting
of its corresponding two-position switch.
Each input is normalled to a precision +5V DC voltage source. With nothing plugged into the jacks,
each knob controls a voltage range of 0 -to- +5V or -5V -to- +5V depending on the position of the
mode switch.
Each output is normalled to mix into the output of the channel to its right making it possible to do
sub mixes in groups of 2, 3 or all four channels.
NOTE: Earlier versions of Quadratt had a different type of physical switch and slightly different
labelling, but are otherwise identical to the version illustrated and described by this manual .
Usage Examples
This humble collection of simple parameters provides a wealth of useful functions to the modular
synthesist. Here are some basic examples of how you might employ Quadratt in your patches:
● Attenuation : Assume you want to subtly modulate filter resonance, but your filter of choice
doesn’t have a built-in attenuator on its resonance CV input. If you were to plug the output of an
LFO directly into the resonance CV input on your filter, you’d be modulating it at full amplitude
— meaning your LFO would cycle the resonance from “none” to “ear shattering squelch” and
back again. But what if you just want resonance to undulate a little bit? Quadratt to the rescue!
Plug the output of your LFO into the Quadratt’s IN A , then plug OUT A into your filter’s
resonance CV jack. You’ll now be able to “dial down” the peak-to-peak amplitude of the LFO
using the Quadratt’s corresponding attenuator knob.
● Inversion : Assume you want to control a module with an envelope. Normally, voltage increases
during the attack section of an ADSR, then decreases during the decay or release segment. But
what if you want the inverse? What if you want some sonic attribute to get more pronounced as
the signal decays, not less? For this you need to invert the envelope. Once again, Quadratt to
the rescue!
Plug the output of your envelope into Quadratt’s IN A , set Channel A’s polarity switch to -/+ , then
turn its attenuator knob counterclockwise past 12:00 — an inverted envelope now appears at
Quadratt’s OUT A .
● Voltage Offsets : Assume you have a Sample & Hold module sending random notes to an
oscillator, only you want to constrain that unruly 10+ octave range of notes to just one or two
octaves in the bass range. One way to do this is to use two channels of a Quadratt.
Plug your S&H output into Quadratt’s IN B ; connect OUT B to your oscillator’s pitch input; then
use the Channel B attenuator to limit the range of notes to an octave or two. Next, use
Quadratt’s Channel A (into which nothing is connected) to negatively offset the note range down
Quadratt 1U Manual 6