new module working

Haible_Juergen#Tel2743 HJ2743 at
Mon Aug 28 19:35:00 CEST 1995


After many months of waiting for the right pot's
I can go on building my Modular. I finished another
module last night. Nothing special, just a mixture
of very common functions, but for those who might
be interested, here comes the description:

The module consists of

1 VCA (input, output, cv, Initial Gain). 3080-based.
   Increasing Initial Gain decreases CV sensitivity,
   so with 5V envelopes there is always a constant
   peak output voltage, independent of the Initial

1 Modulator (input1, input2, output, Gain1). 1496-based
   Ring Modulator. Input1 handles smaller input voltages,
   anjustable by a pot, and Input2 is designed for +/-5V

2 Mixers (in1, in2, out, Balance). Balance pot buffered
   by 3 emitter followers. DC-coupled.

The inputs of Mixer1 are normalized to input1 and output
of the Modulator. This way, the Mixer's Balance poti
can fade from straight input signal over amplitude modulator
to ring modulator.

1 Noise Generator (White, Pink, Random, Drift). Analogue
   design with the usual reverse transistor. Quite large RC
   circuit to get a well approximated Pink spectrum, copied
   from the Moog Modular. The Drift pot affects the cuttof
   point of the random Voltage (12db/Oct).

1 Sample & Hold (in, clock, out, Lag). Discrete JFET switch.
   Contains schmitt trigger + differentiator to clock the S&H
   from almost any LFO waveform (as opposed to MS-20).
   Simple exponential Lag.

The input of S&H is normalized to Random, of course.

As I said, rather common functions this time. But nevertheless,
it's a great moment when you finish a module you started
building half a year before, and it works.


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