The Model 13 is an enhanced derivative of the infamous Buchla 292 Low Pass Gate.

Like all Lowpass gates, at the heart of the Dual Timbral Gate is a device known as a Vactrol -- a small electro-optical coupler which opens the filter with it's characteristic ringing qualitiy. As sonically compelling as they are, Vactrols however are not perfect. While some of their anomalies are desirable (ringing for instance), others are not. Long story short - Vactrols leak. Not vactrol juice, but sound passed through them, even when you're telling them to be quiet. While it can't be eliminated without jeopardizing the ring, it can be improved upon and the Model 13 does just that, decreasing the nominal leakage associated with other LPGs by a factor of 10, from 3mv to just a under one third of a mv...barely audible even in at very high volumes.

Each gate is fitted with an offset knob which serves two functions: If no VC is applied, they act as manual level controls. Once a VC is patched they act as low threshold offsets, as the gate will not close below the level set on the pot. A three position switch selects the modes of operation: Amplitude only (no filtering), LowPass (high filtering) or Both (a combination of Amplitude and Lowpass settings). The M13 has been further enhanced by a dedicated crossfading sum output, allowing for a sonic mixtures of the information passed through both. One application for this output being when both gates are set to amplitude mode, your DTG becomes a handy 2 in, 1 out mixer!

Sound Sample:

One sample is all that's required. The following small patch will gives you the big picture:

Two Model 15's, tuned slightly off unison are being fed alternately into a standard VCA and then switched into the MOdel 13 Dual Timbral Gate set to 'both' mode. The control path for the VCA and DTG are identical: A very short (0 attack, 0 release) A/R envelope is opening the two gates and also into the VC freq inputs of the VCOs for a slight percussive 'chiff'

Click here for the sample

Notice when the patch is being gated through the VCA all you're hearing the snap of the chiff. The event is SO short it's impossible to even discern the pitches involved. When run through the DTG however, the sound comes alive. Due to it's tendancy to smooth sharp attacks, the chiff becomes a natural sounding percussive augementation and what appears to be an added envelope decay isn't - it's just the ringing effect of the DTG itself. The envelope settings on both the VCA and DTG are identical.

Sound Samples by Zoran Bosnjak:

The following were realized by Plan B customer Zoran Bosnjak incorporating a mixture of Plan Model 15's, a M13 Dual Timbral Gate and a Livewire Frequensteiner filter:

sample 1
sample 2
sample 3
sample 4
sample 5

Demo track by Dan Levey:

"This is a 2:07 Demo that was made using only the Model 15 Oscillator as a source for all sounds including drums. Only modulation to the osc was using it's own waveforms to cross-mod others, noise into the sine to make hi-hats and snares and lfo and envelopes to cv or the morph input."

sample 2

Model 13 in the movies - Peter Grenader demos a Model 13 and 15 at Big City Music: click here

Why Model 13 you ask? It's elementry - 2 + 9 + 2 = 13!