To: analogue@hyperreal.org,
From: Michael Caloroso MLCaloroso@worldnet.att.net,
cc:
Subject: DIY Modify your Moog Source/Memorymoog: Boot-up to Octave "0"
Date: Thu, 16 Jul 1998 18:45:38 -0700


When you turn power on to the Moog Source, it wakes up with Octave
button "+1" set. If you use your Source primarily for bass, you have to
manually push the Octave "0" button each time you turn it on.

Likewise with the Memorymoog, which wakes up with Octave button "-1"
active. Trouble is, the factory patches are set for Octave "0". To
maintain convention, I program my patches with Octave "0".

All you have to do is solder a 0.022uf nonpolarized cap across the
Octave "0" button terminals, and they will wake up at Octave "0". Over
time you will appreciate the convenience of this.

What happens is that when power is off, the voltage across the cap
diminishes to zero volts and stays there, effectively shorting the
button contacts. When you turn power on, the voltage across the cap
starts to rise to the power rail, but this rise is slow enough for the
circuitry to sense a switch closure. Once the cap is charged up, the
switch looks open and will act normally.

MC