Dual ADSR/VCA with Cycling Gate Pulsers

Tangrams, like our Dual ADSR before it, is a dual analog core-envelope inspired by the Roland SH-101 / System 100m design with several enhancements. Taking further inspiration from trapezoidal function generators like the one on the EMS Synthi, we have added a voltage-controlled pulser circuit to link the triggering of two envelopes - allowing for delayed one-shots, cycling organic envelopes, and more. In addition, we've added two VCAs for level control of each envelope, or alternatively, direct injection of the signal you'd like to envelope - freeing up your other VCAs.

The Pulser

The Pulser can be thought of as a way to set both a gate ON time (T1) and an OFF time (T2). In this way, you could configure a cycling ADSR that has a gate time that is different from the interval between gates. Alternatively, you can create a sequence where ADSR2 is triggered by a delayed amount of time after ADSR1 is triggered (either cyclically or in a single shot sequence). The panel switches for routing or disabling the pulse sources allow for even more complex combinations of control beyond these examples. This special combination of functions can yield a plethora of interesting and organic envelope and gate patterns to be created; cyclical and single shot.

ADSR + VCA Features

• Dual Analog ADSR envelopes with digital gate Pulser for trapezoid shapes

• Pulser stages P1 and P2 can be selectively routed to trigger each ADSR via panel switches

• Three timing ranges: (FAST: ~5 seconds, MED: ~35sec, SLOW: ~1min A/D times)

• Retrig input (allows re-triggering of the envelope if source gate held high)

• VCA input can be used to dynamically control the respective ADSR output level (bipolar) or to process signals to be modulated in amplitude by the ADSR.

• Manual GATE buttons for each envelope

Pulser Features

• A pulse is made of individually controllable T1 and T2 stage lengths

• CV control over T1 and T2 time

• Pulser can be one-shot (SINGLE) or repeating (CYCLE)

• PULSE output has a switch to select P1 or P2 as the source.

• Pulser stages P1 and P2 can be selectively routed to trigger each ADSR via panel switches

• START trigger input for starting/restarting the Pulser sequence

• Manual GATE button to trigger the Pulser sequence