Eric's Tube Synth

[Robert Edgar]

What a treat--I got to play with Eric's voltage-controlled modular tube
synth yesterday.
Elements included:
	o a quad VCO
	o a dual VCO
	o a VCA
	o a VCF (switchable between low and high pass)
	o an AR envelope generator
	o a  beam modulator (this was new to me, Eric explained that it
acted something like a balanced modulator, but with different processing of
overtones, and some passthrough of fundementals.
	o a 2.5  octave keyboard that controlled two of the VCOs

For a complete description of  interface elements, see Eric's schematics.

The modules were mounted in a standard rack, about 24" high,  black panels
with screened white lettering.  It was quite portable.

Eric flipped it on, it took a few minutes to warm up and stabilitze.  Once
it did, it produced a beautiful, (is it a cliche to say this?) warm
sound--to my ears, the sawtooth-like waves sounded very full of evenly
amplified- and densly- packed harmonics.  This gave quite a bit to
manipulate when playing with the pots:  very easy to tune into various
areas of the sound spectrum that had interesting things happening, and
bring them out by fine tuning.  You could certainly get harsh, dirty sounds
(pulse wave type clicks etc.), but what stood out to me were the
soft-edged, slightly pitched sounds--very nice.

Eric provided a nice magnet that warped the beams of a couple of  the
tubes, and gave a kind of filtering effect that was interesting.

It seems to me that Eric has gotten around to finally producing the first
synthesizer--the one that the industry forgot to produce, when it took
voltage control straight to solid state.  At last--the first synth!

The signal is patched using standard patch cables.  I look forward to
spending some more time with it, comparing its sounds side by side with a
solid-state synth.  Truly enjoyed playing it, nice work, Eric.

Robert Edgar
lull at iconceptual.com