[sdiy] Noise Engine Progress

[Michael Ruberto]

White noise and plenty of it. After experimenting with a handful of 
different transistors I found the all-time king monster of noise makers - 
ECG128. This TO-39 brute just pumps out the noise. Initially I was using 
2n3904 and the loudest of the batch still required a 1st stage gain of 136 + 
2nd stage gain of 3 which got me almost 1V PP. I stuck the ECG128 in and 
nearly blew my speakers out! Now 1st stage gain is only 9.2 and 2nd stage 
gain 3 for a output of over 5V PP. It's great, less gain more noise with 
that same refreshing taste.

I could not find a pink noise filter I liked out of all my schematics. So I 
started playing with comparators for digital noise. Best sounding I got here 
is to send WN to comparator 1 and inverted WN to comparator 2. Setup a 
divider for each so they trigger about .75V apart. Then AND the outputs 
together with diodes. It sounds VERY crunchy. I think I'm calling it Dirty 
Noise.  It will convert to a nice sounding pink noise with one .022uF cap 
from the output to ground.

I'll get some schematics drawn tomorrow.

M. A. Ruberto