[sdiy] best soundign vco design?

[Dana Scott]

I have seen at least one site on the 'net with schematics of the potted modules
posted.
Early potted modules were completely encased in epoxy. By the time I started
working at ARP (Feb. 1974) they were potting them in soft RTV rubber with a thin
layer of epoxy on top. These were frequently cracked open and repaired.  The
Avatar E' module was an exception. All of those were hard potted... Well, not
_all_ of them. I have one that is not potted.
Somewhere in my files I have a 1:1 film negative for a 4027-1 VCO.  I don't
think board houses will accept films without NC drill info anymore. On one of my
old computers I have a CAD board layout I did of one of the modules, ring mod I
think.
I was thinking of running off a batch of 4109 filter modules. The 4109 is the
filter used in the Centaur prototype. It is a VC state variable filter with low
pass , high pass, bandpass and notch outputs, It uses the same basic filter
section as the 4075 and 4072 filters and has voltage controlled resonance too.
Do you think it would be work my effort to produce a batch of these?

-Dana



----- Original Message ----- >

> Any of you guys know if the details of those potted modules that ARP used to
> use ever got out?  Just curious,  mostly...
>
> Wanna talk about "fat" sound?  Best I ever did was to have _THREE_ 2600s
> finished up at one time and still on the bench.  So of course I patched 'em
> together... :-D
>