[sdiy] Yet another 292c Lowpass Gate audio sample uplaoded

[Peter Grenader]

Peoples,

To augment Mr. Winstanley's Lowpass Gate soundfile, I have added one of my
own to my site which gives an example of the 292c circuit controlled by an
extremely short transcient-type  envelope.

Two things will be instantly evident when you hear it:

1)  No pop.  Do the same thing using a standard VCA,  with an envelope as
short as the one I have used and the usual VCA crack*pop*snap will be heard
as it opens and reacts to the voltage applied.  The vactrol in the lowpass
gate by comparison affords a slight smoothing of control voltages as the led
turns on.

2) The ringing in 'combo' mode.  When the Low pass gate is set so that the
switch is on the middle position, one hears a mix of the standard VCA and
the low pass gate in equal amouts.  The net effect of this is a wonderfully
natural sounding ringing  which is very audiblet with short envelopes like
I've used here  Chalk this up to the vactrol LED now dimming off and the
removal of the .0047 cap within the circuit.

In the ate used in this sample I used polystyrene's for all caps which are
directly related to the audio path. The other two are combinations of
different types of caps in these places which was done intentionally to give
each a slightly different persoanlity.  I can't tel from Kieth's picture
which type are on his, but they sound like mylars (one of mine uses those as
well). 

Another application hint for the lowpass gate is setting the output level of
the control source you're using to open it with to the bare minimum required
to turn on the led in the vactrol - just a touch past the signal being too
low to excite and open the gate.  I usually use my Blacet EGs for the LPGs,
where John's output level pots come in very handy for just this.  Using too
much juice will cause a little clipping.  Backing it off will yield what
you'll hear in this sample.  I assume this is due to the signal levels of
the Buchla the circuit was designed for.

To give this a listen, go here:

http://www.allegrobikes.com/synth.html

click on 'Son of Frankensynth"

Scroll down to Homebrew modules link

Scroll down to the Low Pass Gate listing on that new page

click on the 'submit to the LPG' button and you will be directed the the
correct download link for the soundfile.

To jump there immediately, simply go to:

www.allegrobikes.com/lpg.html

enjoy.

or not.

P