Fw: [sdiy] The simplest synth ever (was: Russian parts and synthschematics...)

[Jaroslaw Ziembicki]

----- Original Message -----
From: "Jaroslaw Ziembicki" <aon.912230836 at aon.at>
To: "mikas" <mikas at turbodsl.lt>
Sent: Monday, September 06, 2004 7:27 PM
Subject: Re: [sdiy] The simplest synth ever (was: Russian parts and
synthschematics...)


Hello!

 (a) If you don't build the keyboard part, then:
- remove VT1...VT7, R1...R14, C1...C6, VD1, VD2, L1,
  S1.1...S1.N+1 (TL271 doesn't need to be used);
- connect DD1.1 pins 1,2 to ground or to +8V;
- at R17, the pin marked as "2" is the CV input (1 volt per octave);
- pins 8,9 of DD1.3 = gate input (negative logics: +8V = no gate,
  0V = gate; you have to add a 100k "pull-up" resistor between these
  pins and +8V, and a 1k...4.7k  "protection" resistor from these pins
  to the gate input jack. If you need a positive logics, you can use the
  free DD1.2 gate as an inverter.
(b) You can replace VT9 and VT12 by a CA3046 as follows:
- VT9: emitter = pin 3, base = pin 2, collector = pin 1;
- VT12: emitter = pin 13, base = pin 12, collector = pin 14.
  The remaining pins of CA3046 should be left unconnected.
  CA3086 can also be used (same pinning).
  An additional circuit for temperature stabilizing can be built later.
(c) You don't need the DA1 amplifier if you don't want to have a
  loudspeaker.

Best regards,
Jarek