Doepfer A-171-2 Vintage

Much more than just a plain slew limiter the A-171-2 is a multi-functional module for generating and processing control voltages and audio signals in the manner of a function generator. LFO, envelope generator, slew limiter... plenty functions are possible!

You can even use the module as a simple waveshaper or a very rudimental filter. The A-171-2 has been created in licence from Ken Stone.

The IN socket is the input for signals to be processed. Gate and Trigger signals at the TRIG input cause the module to produce one rise/fall cycle what can be considered an Attack/Decay or Attack/Hold/Release envelope. The time parameters "up" and "down" (or rise and fall) can be set manually and by control voltages (with polarizer type attenuators). The Up-CV input is normalized to the Down-CV input. Additionally there is the exp-CV socket controlling both parameters which has a voltage characteristic of almost 1V/octave. The curve characteristics can be switched from linear to non-linear separately for each time constant; the characteristic of nonlinear settings can be set from exponential over linear to logarithmic with potentiometers. This makes it possible to set a certain punch of an envelope, for instance. The END output generates a gate when the output signal drops below 20mV. Connecting this out with the trigger output makes the A-171-2 oscillate what can be used to LFO and oscillator applications. You don?t need to patch, though - just activate the Cycle switch!