Classic Buchla Bongo

— Notes —

A sine wave from the Model 258t hits the Quad Lopass Gate Model 292t to create Buchla's iconic round and organic sound. The Model 281t generates a self-contained cycling clock and a very short envelope with pitch bend to emulate hitting the drumhead.

To Play It

Listen to the Mixer/Preamplifier Model 207t signal output L. The patch loops automatically. Adjust Quad Function Generator Model 281t A decay to change the tempo, and Dual Oscillator Model 258t osc 1 freq to tune the bongo.

Cables

1. Quad Function Generator Model 281t A pulse out → Quad Function Generator Model 281t B trig
2. Function A's end-of-cycle pulse triggers Function B's percussive strike at a steady tempo.
3. Quad Function Generator Model 281t B out → Quad Lopass Gate Model 292t cv in A
4. The short envelope strikes the lopass gate's vactrol to simultaneously open amplitude and spectrum.
5. Quad Function Generator Model 281t B out → Dual Oscillator Model 258t osc 1 fm input
6. The envelope slightly modulates the oscillator pitch to simulate the initial pinch of the bongo membrane.
7. Dual Oscillator Model 258t osc 1 output 1 → Quad Lopass Gate Model 292t signal in A
8. Oscillator 1's pure sine wave enters channel A of the lopass gate.
9. Quad Lopass Gate Model 292t out A → Mixer/Preamplifier Model 207t input A
10. The audio signal struck by the lopass gate is sent to input A of the mixer.

Settings

• Quad Function Generator Model 281t · A cycle mode : pos. 3 / 3
• Sets Function A to cycling mode to serve as a self-contained clock.
• Quad Function Generator Model 281t · A attack : fully counter-clockwise
• Minimum attack for the clock cycle.
• Quad Function Generator Model 281t · A decay : 11:30
• Defines the steady tempo of repeated strikes.
• Quad Function Generator Model 281t · B cycle mode : pos. 1 / 3
• Transient mode to generate a single shot per trigger.
• Quad Function Generator Model 281t · B attack : fully counter-clockwise
• Instantaneous attack essential for the percussive snap.
• Quad Function Generator Model 281t · B decay : 8 o'clock
• Brief decay to get the short, dry resonance of the bongo.
• Dual Oscillator Model 258t · osc 1 freq : 10:30
• Round and warm fundamental pitch in the lower-mids.
• Dual Oscillator Model 258t · osc 1 waveshape : fully counter-clockwise
• Pure sine wave shape for a soft, woody sound.
• Dual Oscillator Model 258t · osc 1 fm : 8:30
• Attenuates the pitch modulation to a subtle tight drumhead pitch drop.
• Quad Lopass Gate Model 292t · A : fully counter-clockwise
• Gate closed at rest, sound only appears during strikes.
• Quad Lopass Gate Model 292t · mode A : pos. 2 / 3
• Lopass gate mode to exploit the vactrol's natural and dynamic decay.
• Mixer/Preamplifier Model 207t · level A : 80 %
• Output level of track A on the mixer.
• Mixer/Preamplifier Model 207t · prog A : pos. 1 / 2
• Routes channel A to the main output.