Thanks for all the positive responses to this idea. I'll keep searching for a schematic and maybe something will turn up eventually.
Am currently working on a MidiBox project, some variation of that seems like it could be a candidate for this purpose.
//Did you install a diode when you swapped for the Lithium battery ?
WT, No I didn't. Thanks for the tip, I wasn't previously aware that this was a requirement with this type of battery. A bit of research prompted by your suggestion reveals that this is in fact the case.
Brian
--- In Simmons_Drums@yahoogroups.com, Jacquot.Patrice@... wrote:
>
> 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@...>
> Ã: "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
>