Doepfer A-171-2 Vintage

The A-171-2 from Doepfer, in its stylish Vintage Edition with a black panel and custom knobs, is far more than a typical slew limiter—it's a versatile CV and audio function generator based on the Bananalogue VCS design by Ken Stone.

At its core, the A-171-2 can act as a slew limiter, LFO, envelope generator, waveshaper, or even a basic filter. It features separate rise and fall controls with CV modulation for each (including an exponential 1V/oct CV input), allowing you to shape curves from exponential to logarithmic independently. With its cycle mode engaged, it transforms into a looping envelope or oscillator—perfect for both audio and modulation duties.

You can trigger rise/fall cycles via the TRIG input, or process incoming voltages directly through the IN jack. The END output sends a gate when the output signal finishes its cycle, making it easy to chain multiple modules or set up retriggering LFOs.

• Function generator with voltage-controlled rise/fall

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

• Manual and CV control for rise and fall times with polarizers

• Independent curve shaping: linear to log/exp

• Exponential CV input (1V/oct) for both rise and fall

• Cycle switch for LFO or oscillator mode

• END gate output for cycle completion

• Based on Ken Stone's CGS/Serge-inspired design