[sdiy] best soundign vco design?

[Rude 66]

how about the 2500's 1047 multimode filter? one of my favourites..


----- Original Message -----
From: "Dana Scott" <danas at egosys.com>
To: "Roy J. Tellason" <rtellason at blazenet.net>;
<synth-diy at dropmix.xs4all.nl>
Sent: Saturday, June 12, 2004 1:26 PM
Subject: Re: [sdiy] best soundign vco design?


> 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
> >
>
>
>