In the beginning there was Light, and the Vactrol opto-coupler was born. (Well, in the early 1960's anyway)!

In these days of quantum-level high-speed electronics it might be hard to imagine why we would actually want to use such sluggish CroMagnon components as the lowly Vactrol, (essentially a photocell and a light bulb)...

Harnessing these into an alchemy of music, fire, and light was the genius of Don Buchla who thought to exploit the quirks or so-called flaws of these components for their musical capabilities instead!

Nothing can match the buttery soft response this circuit evokes when commanded "to dance!" by an impatient pulse or envelope.

That unique flitty, percussive, Subotnick trademark type sound can be realized with these gems because they are based on the original Buchla 292 circuitry. There are four on this panel, each with a switch to determine if there will be additional Low Pass coloring to the signal as it passes.

Often a signal is best processed through two or more of the module's channels in series, and always a delight when used in concert with the Modcan 08A Processor's preamp and envelope follower on external inputs.

Below are four .wav file samples featuring the Cynthia/Buchla Lowpass Gate prototype, demonstrated by Peter Grenader using a single patch in which only the Gate's modes are changed. The attack time of the envelope is increased midway through each to give an idea of the full dynamic effect of this instrument.

"The Low Pass Gates are something that I had no idea what I was buying when I ordered them. Boy am I glad I did! That sound is fantastic, so organic - slippery, rubbery textures - very cool indeed!!"
Steve