Toppobrillo - Cluster

Cluster is Toppobrillo's interpretation of the Buchla 257 - a CV processor with many possible applications.

Basically, Cluster consists of a polarizer channel, a crossfader channel, and an attenuator/offset channel.

XY (Polarizer Channel):

The upper section of the module is a voltage-controlled " polarizer", or more precisely a four-quadrant multiplier. It multiplies two signals, "X" and "Y", which can then be tapped at the X(Y) output as the product of these two sources. The Y input is normalized to an offset voltage when unpatched and therefore acts as the default processing channel, giving X1 when fully clockwise and X-1 when fully counterclockwise. Looping a source into the Y input cancels this normalization, and the "Y AMT" control now scales (multiplies) the source looped into Y to give Y1 at full clockwise and Y-1 at full counterclockwise. This is useful in that the upper section can easily be patched as a standard VCA with a positive CV.

A->B (Crossfader Channel):

In the center of the module is a linear crossfader. The knob and the A->B CV input sum mix A to B and everything in between.

The 'REF' switch, when activated, passes a selectable offset to the normalization of input A.

Z (Attenuator/Offset Channel):

The lower part is another processing channel with an offset normalized to its input, acting as a manual offset control when unpatched. Patching to Z removes this normalization, and the Z AMT control now multiplies the Z input to produce Z1 when fully clockwise and Z-1 when fully counterclockwise. An LED indicates the output amplitude and polarity.

Sum outputs:

There are two SUM outputs, "∑" and the complementary "-∑" . The SUMs are a summation of the three sections. If one of the outputs of the three sections is patched, it is removed from the SUM outputs.