[sdiy] Telharmonium motors, perhaps?

[Gene Stopp]

Yup that's the idea, a tape recording of some waveform or another, speeding
up and slowing down. Mellotrons run at a constant 7.5 ips with the pitch pot
at center position. And they're not looped (usually).

This idea sounds a little goofy. Many of the ideas that pop up on this list
sound a little goofy. Like using a CV to select MIDI ports, or huge matrices
for modular patch signal routing, tape head wands, tube synthesizers, etc.
But they are NOT goofy! Here's why:

a) This is a hobby, dammit
b) This is art, dammit
c) Our creations are manifestations of creativity, with a technological
twist
d) The sounds are cool too

Seems to me the tape VCO would only be good over a couple of octaves. The
portamento rate might be different depending on whether it was spinning fast
or slow in the first place. And I bet it would go through tape pretty fast,
if it's running all the time like a "normal" VCO. Be a bummer to have it
sitting there during a gig, and the last key you hit was the highest note,
the tape inside eating itself alive...

Maybe the optical disk would be better. Or just the tonewheel. That would
sure be a heck of a lot easier to build too. You could mix the tone with the
real VCO that it's phase-locked to. You could also have two or three
motor-tones behind the real VCO. They would all probably have different
mechanical characteristics for interesting tracking effects. Also with the
spinning disk idea you don't actually need a separate tach output, just use
the tone itself for the PLL compare.

Allright this is getting out of hand. Cut it out... must... not... start...
new... projects...


- Gene

-----Original Message-----
From: Glen [mailto:mclilith at charter.net]
Sent: Monday, November 22, 2004 4:02 PM
To: Gene Stopp; synth-diy at dropmix.xs4all.nl
Subject: RE: [sdiy] Telharmonium motors, perhaps?


At 05:49 PM 11/22/04 , Gene Stopp wrote:

>I think it was in an old Crowhurst book that I read about a VCO that was
>actually a tape playback with the motor speed (and therefore the pitch)
>under voltage control.

That sounds interesting! I bet a lot of analog lovers would be drooling at
the thought of the built-in tape characteristics imparted onto the sound. I
wonder if the speed could be changed quickly enough to build a monosynth
out of such an oscillator? I bet it would have its own special
"portamento-like" effect on each and every note, unless the motors could
change speeds *very* quickly. The possibility of unique pitch slurring
might even add to the unit's analog charm.  :)

If such a monosynth were actually built, I would think any flanging,
chorusing, and distortion effects should also make use of a tape transport
system. I know that Mellotrons used tape, in a sampler style, but I don't
think this would be the same concept at all. You're talking about using a
tape transport in the core of an oscillator, and not as a "sample player",
isn't that correct?


take care,
Glen