MOTM update & contest!!!

Paul Schreiber synth1 at
Wed Jan 14 00:16:32 CET 1998


1) The AGC'd noise circuit proved to be too sensitive to components on the test bench. So, I have the EMu's
front end (dual Zeners + JFET buffer) and a standard output stage with a trim pot for level. This you could drill
another hole for a front panel adjustment as well.

2) Thanks to a suggestion by Rodger Arrick, the sample/hold will offer a unique feature, not found on any other
synth. The LF398 chip is actually a TRACK and hold: when the control input is in one state, the output is the 
input. It holds in the other. Now, what is usually done is to add a 1-shot of say 1ms to acquire the signal, and
hold it. This is evident if you have a 1Hz square wave clock and you are trying to sample white noise for a VCO input.

But, I am adding a switch to route AROUND the 1-shot, so that it will track & hold. It will do this at HIGH SPEEDS,
so we have a type of timbre modulator if you feed say a 1Khz sine wave in, and a 330Hz clock into it. It is also
a simple on/off switch, in a manner of speaking. An analog equivalent of a 74LS373 transparent latch!

This should be interesting!!


I am using CorelDraw (Version 8) as the silkscreen interface to my painter for the front panels. So, for the 2 weeks
before I go off to the metal shop, I thought since I have ZERO artistic talent, why not have a contest?

I am offering a $50 off coupon (virtual, of course) to the winner of the contest: design a logo to go on each panel.

Rules are as follows:

1) Must be received by 1-28-98
2) Be 1 color: send it in black.
3) Be in a format I can read. Prefer, in order CDR, TIF, PCX, EPS, DXF, GIF, JPEG, BMP.
4) Be able to be readable when shrunk to 19mm high. No type smaller than 10.
5) Each module will say something like:


You can have a pure graphic logo, use MOTM only, use Synthtech only, etc. The width can be up to 58mm wide.

Back to the testbench!

Paul Schreiber
Synthesis Technology

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