Vintage Simmons Drums (UK) Users Group

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@...>
> 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
>