Usefulness of 'Slow Random' noise versus 'Boing' filter

Paul Schreiber synth1 at
Mon Mar 16 19:31:53 CET 1998

Actually, this is the sort of stuff I get on MOTM Noise board prototype. The original Electronotes circuits talks about
"10 volts pk-pk at around 10Hz", but no way!

I use a 150K feedback with a 22K input resistor, and get about 40Hz average out at around 0.75V pk-pk. Which
makes sense.

I guess the question I have:  is it usefu??.

I was playing around with the 'Random Vibrato' filter. If I patch it up the the s&h clock, I can real nice 'boings' out
of it (the 'boing' time set by the Q pot). The original circuit was triggered by white noise, but unless the Q is very
high, not much happens. At high Q, the filter self-oscillates at a fixed 7Hz.

So, what if I scrap the "Slow Random" jack, and use it as an input to the boing filter. I can normalize it to the
internal S&H clock. Any sharp edged input <7Hz would boing it as well.

Paul Schreiber

From: 	Roy Tate[SMTP:roytate at]
Sent: 	Monday, March 16, 1998 10:58 PM
To: 	'Paul Schreiber'
Subject: 	RE: ASM1 Noise Gen question

>Just curious what the 'Slow Random' output voltage is on a scope. 
>Amplitude and frequency range.
>Paul Schreiber

I am getting about 30 Hz and about 0.5v (not optimal!) from 
a 2N3904 in my ASM-1.  The signal seems to favor positive
voltages, with occasional negative excursions.

Frequency measured with a Fluke meter, amplitude 
measured with standard opto-neural linkage [eyeball :) ]
on a scope.


Roy Tate
roytate at

More information about the Synth-diy mailing list