TipTop Audio Buchla 264t Quad Sample and Hold/Polyphonic Adapter Module

The Tiptop Audio Buchla 264t Eurorack module features four independent sample-and-hold circuits, plus a specialized logic circuit for expediently implementing polyphonic patches. Sample-and-holds are essentially one-cell analog memories. They are useful for “remembering” the instantaneous value of a control voltage (a detected envelope, for example), for generating equally spaced steps from a constant slope input (as from a 281t envelope generator), and for converting any continuously changing voltage (a random voltage, for instance) into a series of discrete values.

The 264’s sample-and-hold circuits have two operating modes: sample and track. In the sample mode, the value of the input is sampled and applied to the output whenever a pulse is received. The output remains at this value until the next pulse arrives. The track mode differs in that an input is applied to the output for the duration of the pulse. The output tracks the input until the end of the pulse and remains at a constant value until the next pulse. To use the 264t as four independent channels set the separate/common switch to separate. A single CV can be set to all four channels by setting the operate/common to common and plug CV in the the back jack on the with right side.

The Model 264t includes a polyphonic adaptor, which performs the logic necessary to implement four-voice polyphony. Facilities are incorporated for fine tuning and F.M. modulating the oscillators; light emitters display the adaptor’s operation.

The four voltage control outputs are internally routed to a quad-channel quantizer with four ART outputs for use with ART-equipped oscillators, such as the 259t Complex Oscillator. A 12-stage switch selects the key, while the knob above chooses the scale: Minor (m), Chromatic (ch), or Major (M).

Auto-Tune can be sent periodically to correct tuning if it sounds like the oscillates are out of tune. (Beware that the fine tune knobs on the 259t needs to be set fully CCW for the note center pitch) To send an Auto-Tune command short press the tuning switch on the 264t.

TIPTOP AUDIO BUCHLA 264T FEATURES:

• 4-channel sample-and-hold module with specialized logic circuit for introducing polyphonic patches
• Per channel independent or shared VC source
• Selectable polyphony up to four voices
• Four voltage control outputs internally routed to quad-channel quantizer with four ART outputs for use with ART-equipped oscillators
• Auto-Tune can be sent periodically to fix tuning if the oscillators sound out of tune