TipTop Audio

Buchla Model 281t Quad Function Generator


TipTop Audio has teamed up with Buchla to revive Don Buchla’s classic 200 series modules, converting them into Eurorack format.

The 281t Quad Function Generator 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.

When the 281t receives a pulse, a generator’s output voltage ramps up to 10V at a rate determined by the sum of an applied voltage and the setting of the attack time knob. In Sustained mode, this voltage will stay high for as long as the input pulse is maintained; when sustain mode is disabled or the input pulse terminates, the output ramps down to 0V at a rate retermined 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. In Cyclic mode, the cycle will repeat.

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: 28hp
  • Depth: 32mm
  • Power: +12V 160mA / -12V 55mA