Synth-DIY Yahoo! Groups Archives

Thread

SDS9 low volume Hi & Low toms

2014-02-22 by <realmsteel@...>

I bought this SDS9 set a long time ago and am finally getting it integrated into my acoustic set.

In November 2012, I replaced the battery and "Program Variables" pot #3 due to a broken shaft.

I have never really seriously tested this machine out until now, but I think the problem has always been there.

Channels 4 & 6 (High and low toms) have very low volume. The mid tom and snare seem to have ok volume.

You can see the channels are triggering, but the output volume is not right.

Here are some other clues for when I went into to programming mode:

I don't have a bass drum hooked up, so I tested it with a pad.

When I have voice #1 (Bass) selected #7 pot doesn't seem to do anything.

When I have voice #2 (snare) selected, pots 2 & 4 don't seem to do anything.

I don't have a snare pad, so channel #3 was not tested.

When I have voice #4 (hi-tom) selected, pots 1, 4 & 6 don't seem to do anything

When I have voice #5 (mid-tom) selected, pots 2, 3, 5 & 7 don't seem to do anything.

When I have voice #6 (low-tom) selected, pots 1, 4 & 6 don't seem to do anything

Most of the other pots are sketchy especially #5

I don't know how drastic the changes are supposed to be since I've never had a known good working machine.

There seems to be something going on with channels 4 & 6.

What can I check or replace to hopefully get this thing working?

Also, what would be the best way to clean the sketchy pots?

Thanks for any ideas,

Rich

RE: SDS9 low volume Hi & Low toms

2014-03-04 by <realmsteel@...>

I was hoping for some replies, but I guess I'll have a go at it and try to figure this out.

I'll document what I have tried and ask for opinions as I go along.

Does anyone happen to have a schematic of the SDS9 they would be willing to share?

I discovered after reading the manual, you need to turn the pots lock to lock in order to see a change.

That seems to work when the pots are working properly.

I bought some Deoxit and tried cleaning the pots from topside.

Took a while, but several of the flaky ones started working pretty well.

I still have at least 3 that I know of that do not want to work properly.

I already replaced one last year due to a broken shaft.

I think i may just go ahead and replace all the pots so I can rule that out.

The Digi Key PN for the pots I will be using is: 987-1572-ND

The cheapest knobs I found for these pots is:226-1104-ND

They have them in black and clear anodize. Too expensive though and hope to find something cheaper.

Maybe if I find a pot with a different shaft, I can find some plastic knobs.

I still have an issue with low volume on channels 4 and 6. Without a schematic, I really have no good ideas on why this could be. I kind of doubt the pots have anything to do with it. The output level pots for those channels seem to work smooth and you can hear a gradual increase in output as you turn the knobs. The max of both channels, is just too low. I have to have the other channels on about 20% to match 100% of these two.

Feel free to chime in with any part numbers or ideas.

Thanks,

Rich

RE: SDS9 low volume Hi & Low toms

2014-03-04 by <capnfishy@...>

Hi,

There was a Schematic bu Thierry (surname???) I may have a copy - will have a look. Don't think there were any restrictions in circulating them. I'm sure someone can advise if there are. Will have a rummage.

IRO knobs, there was a post a few weeks ago about them but I didn't look at that one. Also, there was a Scandinavian(?) company who do them I recall. Just found the post from 14th May 2010. Company is called Elma but have a large minimum order Ed Rose on this forum bought a stack - he may have some left.

Regards

Jonathan

RE: [Simmons Drums] RE: SDS9 low volume Hi & Low toms

2014-03-07 by Sam Zehr

I used the following from www.smallbearelec.com to replace four pots:

Alpha Single-Gang 16mm Rt-angle PC Mt. Knurled Shaft (100K Linear)

Alpha Single-Gang 16mm Rt-angle PC Mt. Knurled Shaft (5K Linear)

With blue and white capped knurled knobs, the knobs do not match, but they work for now

It doesn’t look like the Digikey part has the right-angle PC mount, hopefully you can bend to fit. The Alpha pots above are the correct mounting style for the circuit board, however the shaft ended up being about 1mm off center to fit back in the case. A slight bend and it all went back together. It now works like original, if not looks original.

If you are replacing all the pots, you may want to check into this – the knobs are much cheaper, and you can vary the colors as you like.

sam

From: Simmons_Drums@yahoogroups.com [mailto:Simmons_Drums@yahoogroups.com] On Behalf Of realmsteel@...
Sent: Monday, March 3, 2014 9:10 PM
To: Simmons_Drums@yahoogroups.com
Subject: [Simmons Drums] RE: SDS9 low volume Hi & Low toms

I was hoping for some replies, but I guess I'll have a go at it and try to figure this out.

I'll document what I have tried and ask for opinions as I go along.

Does anyone happen to have a schematic of the SDS9 they would be willing to share?

I discovered after reading the manual, you need to turn the pots lock to lock in order to see a change.

That seems to work when the pots are working properly.

I bought some Deoxit and tried cleaning the pots from topside.

Took a while, but several of the flaky ones started working pretty well.

I still have at least 3 that I know of that do not want to work properly.

I already replaced one last year due to a broken shaft.

I think i may just go ahead and replace all the pots so I can rule that out.

The Digi Key PN for the pots I will be using is: 987-1572-ND

The cheapest knobs I found for these pots is:226-1104-ND

They have them in black and clear anodize. Too expensive though and hope to find something cheaper.

Maybe if I find a pot with a different shaft, I can find some plastic knobs.

Feel free to chime in with any part numbers or ideas.

Thanks,

Rich

RE: SDS9 low volume Hi & Low toms

2014-03-07 by <warlandr63@...>

That Schematic is very good. It was created by reverse engineering the SDS9 so took a lot of effort. His name is Thierry Eppherre. He is a list member.
I would suggest that you get permission just as a point of goodwill. The last thing needed would be for it to turn up on some pay for manuals site.
The SDS9 is quite complex compared to most brains as the CPU does quite a lot of work and it was the first full midi brain. They all tend to have various issues over time but they are fixable if you have access to some reasonable test equipment and you have a fair knowledge of electronics. I have repaired quite a few over the years. As to what is causing your issues I'd need a fairly detailed description of whats happening to at least head you in the right direction. Is the sound good from the tom individual outs? Is it bad only from the combined outs. Can you vary the volume of each tom? This is the kind of info needed.

RE: SDS9 low volume Hi & Low toms

2014-03-20 by <realmsteel@...>

Sorry I was off on another project for a bit.

I'm not sure how to contact Thierry directly. I did some searches and I can see the first part of his email address, but not the second.

I didn't test the individual outputs. I should have before removing all the pots.

I decided to go with the ones from Digikey I listed.

I already replaced one of them some time ago and it works perfectly.

Basically solder it, then bend it over. It's nice because I can control exactly where the shaft will end up to match the cover.

Thanks for the link to Small Bear. I may buy knobs from them or make my own. I have a small hobby lathe for metal work.

2 pots were definitely flaky. I will feel better knowing they are all new.

Rich

RE: SDS9 low volume Hi & Low toms

2014-03-25 by <realmsteel@...>

I just finished replacing all the pots.

I have to say there was a pretty large variance in the old ones I removed.

Old low of about 30-56 ohms to high of maybe 85-95k

New pots are fairly consistent of about 1-1.4 ohm to 96-100k

Still didn't fix the problem of the mid and low toms with very low output.

The individual outputs make no difference. It almost seems as if the individual outputs have slightly lower volume than the mix. this may not be the case as it was hard to hear over the stick noise.

I can control the volumes of all the pads when using the mix output.

You can hear the volume difference even when using the autotrigger.

It seems to me whatever is driving those two pads is not generating the same output as the others.

Are those two pads paired somewhere.