Buchla 281t


2 in stock


Quad Function Generator Model 281t

The original 281 Quad Envelope Generator is an essential module within a Buchla 200 series system. Don described the 281 as a function generator, rather than just an envelope generator as it’s not your standard ADSR. Depending on how it is patched, it can produce very complex wave forms.

This collaboration between Buchla & Tiptop produces an official representation of this essential Buchla 200 series module in affordable Eurorack form.

The 281t comprises four function generators organized in two pairs. All four generators can operate independently or can be linked in pairs to generate more complex output voltages.

Cycle jack enables the cycling of the corresponding function generator using a gate signal.

Trigger button enables the manual triggering of the function generators.

A switch selects one of three modes: Transient, Sustained, and Cyclic.

Upon receiving a pulse, a generator’s output voltage ramps up to 10V at a rate determined by the sum of an applied control voltage and the setting of the attack time knob. When in Sustained mode, the voltage will stay high as long as the input pulse is maintained; when not in the Sustained mode, or when the input pulse terminates, the output ramps down to 0V at a rate determined by the sum of the decay cv in and the setting of the decay knob.

At the end of the Decay segment, a transient pulse appears at the pulse output. If the 281t is in Cyclic mode, the cycle now repeats.

The time range for both Attack and Decay is from .001 to 10 seconds.

In the Quadrature mode, generators A and B (or C and D) operate in tandem with their functions shifted by ninety degrees in relation to each other.


  • width: 28 HP
  • depth: 33 mm
  • power: 160 mA +12V, 55 mA -12V, 0 mA 5V

Manual: download