Sequential Vactrol Switch

Sequential Vactrol Switch

The Sequential Vactrol Switch is a 6HP module which sequentially routes one of eight input jacks to the output. A trigger or gate at the 'clock' input steps the sequencer by one, and the same at the reset gate returns it to the first input. It was optimized for passing high-bandwidth video signals through, but will work with audio or CV as well. One great benefit of using vactrols as a switching element (besides their inherently high bandwidth) is that the inputs are smoothly slewed or crossfaded. No pops or clicks! The decay time of these vactrols are closer to NSL32s than VTL5C3s, and will vary.

Caveats:

The attenuation for the inputs may not be as high as a typical VCA.
With eight inputs, bleed from off channels may be noticeable.
The gain is not trimmed or uniform enough to expect 1v/oct. signals to pass in a precise fashion.
The input impedance changes when channels are on.  Bonus feature!
This means when a channel goes on, the input signal will get attenuated depending on the output impedance of the module plugged in!

http://modularaddict.com/smrl-sequentialswitch-kit