[sdiy] "Curtis" filter in Prophet 8

[Doug Terrebonne]

Aren't they the same chips Tom O. used in the Marion Systems synths in the early 90s?

--- On Wed, 7/22/09, Paul Schreiber <synth1 at airmail.net> wrote:
> They were custom for Dave only. Try
> calling there and ask.
> 
> Paul S.
> 
> ----- Original Message ----- From: "David Ingebretsen"
> <dingebre at 3dphysics.net>
> To: <synth-diy at dropmix.xs4all.nl>
> Sent: Thursday, July 23, 2009 12:12 AM
> Subject: RE: [sdiy] "Curtis" filter in Prophet 8
> 
> 
> > Well, then I guess my follow-up question would be can
> regular people buy
> > small quantities of these chips somewhere? Or, would
> it have been a special
> > run for Dave Smith only?
> > 
> > 1. It might be fun to experiment with the chips for
> SDIY.
> > 2. I'm thinking of buying a Prophet 8 and the paranoid
> in me would want some
> > spares should the unit fry.
> > 
> > David
> > 
> > 
> > David M. Ingebretsen M.S., M.E.
> > Collision Forensics & Engineering, Inc.
> > 2469 East Fort Union Blvd. STE 114
> > Salt Lake City, UT 84121
> > www.CFandE.com
> > 
> > 801 733-5458 Office
> > 801 842-5451 Cell
> > 
> > dingebre at CFandE.com
> > dingebre at 3dphysics.net
> > 
> > 
> > 
> > ~~ -----Original Message-----
> > ~~ From: synth-diy-bounces at dropmix.xs4all.nl
> [mailto:synth-diy-
> > ~~ bounces at dropmix.xs4all.nl]
> On Behalf Of JJB
> > ~~ Sent: Wednesday, July 22, 2009 6:09 PM
> > ~~ To: synth-diy at dropmix.xs4all.nl
> > ~~ Subject: Re: [sdiy] "Curtis" filter in Prophet 8
> > ~~
> > ~~ On the Dave Smith website he mentions somewhere
> that the Curtis chips
> > ~~ used in the Mopho are not New Old Stock, but an
> actual new run of Curtis
> > ~~ chips. Now how does one go about making _that_
> happen?
> > ~~
> > ~~  - Joel
> > ~~
> > ~~ Antti Huovilainen wrote:
> > ~~ > On Wed, 22 Jul 2009, David Ingebretsen wrote:
> > ~~ >
> > ~~ >> While not strictly DIY, I am curious if
> anyone knows anything about
> > the
> > ~~ >> Curtis low pass filter in the Dave Smith
> Prophet 8 synthesizer? Is it
> > ~~ >> using
> > ~~ >> Curtis chips or did they re-do the circuit
> with discrete components?
> > ~~ >
> > ~~ > My guess is CEM3396, which is basically two
> half DCos, VC mixer,
> > ~~ > CEM337x/338x style filter (similar to OTA even
> if internally
> > ~~ > implemented with some shortcuts) and a final
> VCA.
> > ~~ >
> > ~~ > Antti
> > ~~ >
> > ~~ > "No boom today. Boom tomorrow. There's always
> a boom tomorrow"
> > ~~ >   -- Lt. Cmdr. Ivanova
> > ~~ >
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> > ~~ >
> > ~~
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