Wind-machine

[Magnus Danielson]

From: Niklas Rönnberg <nikro at itn.liu.se>
Subject: Wind-machine
Date: Mon, 07 Feb 2000 11:21:01 +0100

> Hello!
> I would like to build a little and simple wind-machine. Yes, I know that
> I could do that with almost any synth, but I want a stand-alone
> wind-machine. 
> Ok, I need one noise-generator, one LFO, one VCF, and a VCA. But I have
> one more wish; I just want to use transistors! 
> The LFO should do tri, and why not sinus. The VCF should be a Low Pass
> filter. Both the VCF and the VCA can be controlled by the LFO, but the
> VCA should have a pot where I can control the initial level.
> Any comments? Any ideas?

My first comment is that you ougth to look at the VCS3/Synthi-A which has it's
core functionallity in transistors and diodes. Early Moog stuff also apply.
An all-transistor noise source should be simple enougth. Take the ASM-1 NS and
just use transistors as amplifiers instead of op-amps. For VCF will either a
dioded or transistor ladder (EMS or Moog ladder that is) be suitable. VCA is
also easy acheivable since you let a transistor steer the common emitter
current of a transistor diff-pair, and you have yourself a VCA. Then will only
the LFO be left, I come to think of a classic transistor flip/flop
configuration steering a capacitor loading/discharging. It has been all done
before with great success.

It sounds feasable and neither of these parts should be particularly hard to
acheive.

Cheers,
Magnus