Vintage Simmons Drums (UK) Users Group

Hi list,

I put the sold-as-broken-SDS-8 on the bench today, rigged it to a PSU
and it lit up (to my surprise) as they're supposed to. Fiddling with the
controls I came to the conclusion that the presets sound messed up
indeed. A sort of metallic floor tom sound dominating all, though they
differ in length and somewhat in pitch. But forget the disco toms I
remember being there from scratch.

Putting it in user mode everything seems to work basically as I recall
it should (reminding me of why I sold every single one I've come
across). But a few Q's arose:

1. Is the bend up not as wide in the frequency spectrum as bend down? (I
can imagine not since the bend down effect was the desired one at the time)
2. How is noise supposed to sound? (I think it's a white noise burst...
but it's not available here in any case)
3. That noise, is it shared among all the channels? (That could explain
a lot!)
4. Any schematics available on this sucker? (I haven't found any online)

Anyway, I'm surprised it was working this well. But thinking of how the
case looked yesterday I can imagine that shorting all kinds of things on
the board if the former owner just plugged it in as it were.

I hope to get this back in decent shape. It's always fun to save and
protect the Simmons legacy, even though I doubt I'll keep the SDS-8...

--
electronically yours, jesper

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

---

Angaudlinn on iTunes:
https://itunes.apple.com/us/artist/angaudlinn/id582356650

Angaudlinn's playlist på Spotify:
http://open.spotify.com/user/simplyanalogue/playlist/540Srd3zA15pK7G1S8qLHo

Angaudlinn on facebook:
https://www.facebook.com/Angaudlinn

Update: Schematics in hand... :)

Yes, the channels share the noise source and I bet that's bananas since
it's located just below the preset switch board and above where the bent
damage was the worst. Since it's only one IC with a few basic components
around it I might just change the IC and hope that solves it... I might
even have the correct IC with a bit of luck.

Q 2-4 semi-solved. Q 1 still open... though the demos on youtube seem to
indicate my suspicion is correct.

--
electronically yours, jesper

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

---

Angaudlinn on iTunes:
https://itunes.apple.com/us/artist/angaudlinn/id582356650

Angaudlinn's playlist på Spotify:
http://open.spotify.com/user/simplyanalogue/playlist/540Srd3zA15pK7G1S8qLHo

Angaudlinn on facebook:
https://www.facebook.com/Angaudlinn


Den 2016-04-21 kl. 16:05, skrev jesper jesper@...
[Simmons_Drums]:

> Hi list,
>
> I put the sold-as-broken-SDS-8 on the bench today, rigged it to a PSU
> and it lit up (to my surprise) as they're supposed to. Fiddling with the
> controls I came to the conclusion that the presets sound messed up
> indeed. A sort of metallic floor tom sound dominating all, though they
> differ in length and somewhat in pitch. But forget the disco toms I
> remember being there from scratch.
>
> Putting it in user mode everything seems to work basically as I recall
> it should (reminding me of why I sold every single one I've come
> across). But a few Q's arose:
>
> 1. Is the bend up not as wide in the frequency spectrum as bend down? (I
> can imagine not since the bend down effect was the desired one at the time)
> 2. How is noise supposed to sound? (I think it's a white noise burst...
> but it's not available here in any case)
> 3. That noise, is it shared among all the channels? (That could explain
> a lot!)
> 4. Any schematics available on this sucker? (I haven't found any online)
>
> Anyway, I'm surprised it was working this well. But thinking of how the
> case looked yesterday I can imagine that shorting all kinds of things on
> the board if the former owner just plugged it in as it were.
>
> I hope to get this back in decent shape. It's always fun to save and
> protect the Simmons legacy, even though I doubt I'll keep the SDS-8...
>

Be careful when reading the schematics.  Although the SDS8 channels are laid out vertically on the PCB, there are certain IC's which are "shared" between channels and the schematic doesn't show that.  You're right about the shared noise source