Doepfer A-171-2 VC Slew Processor / Generator

The Doepfer A-171-2 is a powerful voltage-controlled function generator capable of far more than basic slew limiting. Based on Ken Stone’s Serge-inspired design and licensed from CGS, it offers a wide palette of uses including envelope generation, LFOs, waveshaping, audio-rate modulation, and even simple filtering.

It features voltage-controlled rise and fall stages with polariser attenuators, allowing you to modulate each stage independently or together using the exponential CV input (nearly 1V/oct response). Curve shapes are adjustable from linear to exponential or logarithmic, making it easy to sculpt the character of your modulation. Trigger the module via the TRIG input for classic AD or AHR envelope shapes—or activate cycle mode and it becomes a looping envelope or oscillator.

The END output sends a gate at the end of each cycle, which can be used to self-patch or trigger other events. With creative patching, this module becomes a highly adaptable modulation and sound-shaping tool in any system.

• Function generator with voltage-controlled rise/fall

• Works as envelope, LFO, waveshaper, or basic filter

• Separate manual and CV control over up/down stages

• Polariser-style CV inputs and exponential CV input (1V/oct)

• Independent curve shaping: linear, exponential, or logarithmic

• Cycle switch for looping envelope or oscillator mode

• END gate output for chaining or retriggering

• Based on the CGS/Bananalogue VCS design