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Subject: Re: [Simmons Drums] SDS 7 Voice Card Reverse Engineering Project

From: Jacquot.Patrice@...
Date: 2010-12-07

by the way, I have a few carcasses in UK to check out ...
but I'm not able to test anything.


----- Mail Original -----
De: "jesper" <jesper@...>
À: "Simmons Drums" <Simmons_Drums@yahoogroups.com>
Envoyé: Mardi 7 Décembre 2010 15h25:15 GMT +01:00 Amsterdam / Berlin / Berne / Rome / Stockholm / Vienne
Objet: Re: [Simmons Drums] SDS 7 Voice Card Reverse Engineering Project






I know WT used to have one or more SDS-7 carcasses with the digital bits
intact (as I recall it). Anything left there? If so, it might be a
better way to solve the problem.

--
electronically yours, jesper

- -- --- ---- ----- ---- --- -- -
www.electronic-obsession.se

brianwright23@... skrev 2010-12-07 07:42:
> Hi, I'd like to introduce myself to the list and see if anyone out there
> has access to a usable SDS 7 Service manual.
>
> My SDS 7 Saga :
> About six months ago I restored an SDS7 which had been sitting on a
> shelf with a burnt out power supply for many years. It worked flawlessly
> with five voice cards for a few months when one day I came into the
> studio and found it had lost it's memory. Turned out that the battery
> for the digital memory had burst. I replaced it with a standard lithium
> memory backup battery of the same voltage from Radio Shack. This
> arrangement worked quite well for several more months, until that
> battery also burst, this time with enough force to effectively destroy
> both of the digital boards, (the ones located behind the keypad).
>
> In the course of rebuilding it the first time I got a pretty good sense
> of the method whereby the parameters are transmitted to the individual
> voices. There is a complex staircase-like waveform that has all the
> analog voltage levels strung together, presumably to be de-multiplexed
> by the "hybrid" module on each voice card.
>
> Now I'm entertaining the notion of embarking upon an effort to resurrect
> the voices using a more modern digital control section, potentially with
> midi control and pots or encoders, per parameter (15 of them). The main
> roadblock at the moment is that I don't have a legible copy of the
> Service Manual which had the circuit topologies. I do have the pdf scan
> which is available at http://www.simmons.synth.net/sds7/
> Unfortunately that scan is of low enough resolution that the important
> details in the schematic sections are totally obscured.
>
> If anyone has, and would be willing to share, this information. That
> would be wonderful. I would of course, in kind, return the fruit of
> these efforts to the list, should those actually bear any usable reults.
>
> thanks,
> Brian