Soundstream repairs/upgrades?

guitarkirb · 29th July 2007, 12:44 AM

I have two old Soundstream d200s and one of them has crispy artifacts in the output as well as mechanical sizzling/chirping coming from the chassis. Anyone know of common failure points for these amps?

I've also heard of upgrades for the power supplies in these units. Anyone have any info on these?

Thanks,

Brian

guitarkirb · 29th July 2007, 12:45 AM

Forgot to mention, the amp in question operates, it just sounds like maybe the power supply isn't behaving well.

1moreamp · 29th July 2007, 08:25 AM

These amps are very straight forward and once restored to normal proper ops that have a very good reputation. Due to its age upgrades are possible through simple parts replacements.

Todays caps are better and smaller, and Fets have been improved for better power handling.

I would tend to make accurate restoration to the amp as parts are readily available from JandR electronics

guitarkirb · 30th July 2007, 03:30 PM

Any recommendations on where to start? I don't want to just start replacing parts until ithe problem clears up. Also, even in factory spec, I can see where the power supply could be improved to get rid of some turn on thumps and strange behaiour.

Brian

1moreamp · 30th July 2007, 04:41 PM

Start with the big capacitors at each channels outputs and the 12 volt side caps. this will most likely bring the power back to clean and possibly stable levels.
caps die of old age just sitting on the shelf waiting to be used, so yes they die in service as well, and in harsh environments well its just a no brainer to replace and upgrade the weak links that fail easily.

Next do a check out of the power supply noise levels with a scope just to garner info at this point.

I would then do a channel check out by measuring the DC offsets on each channel at the output read the DC voltage present at the speaker terminals with a meter, and write it down somewhere. this is done with the amp turned on, and no rca signals and no speaker load.

If you want to lower the DC offsets then i would look at replacement of the two main culprits, the input dual transistors, and the output Darlington devices.

I would not try to upgrade any of the silicon devices unless you have the Engineering savy to resolve the issues you might be introducing to the amp design.

I would only replace those things I understand to be bad with age and leave it at that. The main reason is this is a engineered device and major alterations require rethinking of proper operating parameters and unless you have the time and ability then your just putting yourself into a mess of trouble and headaches.

Best of luck on the rework

guitarkirb · 30th July 2007, 04:44 PM

That's eexactly the type of info I was looking for!

Thanks,

Brian

29th July 2007, 12:44 AM	#1
guitarkirb diyAudio Member Join Date: Sep 2006	Soundstream repairs/upgrades? I have two old Soundstream d200s and one of them has crispy artifacts in the output as well as mechanical sizzling/chirping coming from the chassis. Anyone know of common failure points for these amps? I've also heard of upgrades for the power supplies in these units. Anyone have any info on these? Thanks, Brian

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29th July 2007, 12:45 AM	#2
guitarkirb diyAudio Member Join Date: Sep 2006	Forgot to mention, the amp in question operates, it just sounds like maybe the power supply isn't behaving well.

29th July 2007, 08:25 AM	#3
1moreamp diyAudio Member Join Date: Dec 2005 Location: Northern California	These amps are very straight forward and once restored to normal proper ops that have a very good reputation. Due to its age upgrades are possible through simple parts replacements. Todays caps are better and smaller, and Fets have been improved for better power handling. I would tend to make accurate restoration to the amp as parts are readily available from JandR electronics

30th July 2007, 03:30 PM	#4
guitarkirb diyAudio Member Join Date: Sep 2006	Any recommendations on where to start? I don't want to just start replacing parts until ithe problem clears up. Also, even in factory spec, I can see where the power supply could be improved to get rid of some turn on thumps and strange behaiour. Brian

30th July 2007, 04:41 PM	#5
1moreamp diyAudio Member Join Date: Dec 2005 Location: Northern California	Start with the big capacitors at each channels outputs and the 12 volt side caps. this will most likely bring the power back to clean and possibly stable levels. caps die of old age just sitting on the shelf waiting to be used, so yes they die in service as well, and in harsh environments well its just a no brainer to replace and upgrade the weak links that fail easily. Next do a check out of the power supply noise levels with a scope just to garner info at this point. I would then do a channel check out by measuring the DC offsets on each channel at the output read the DC voltage present at the speaker terminals with a meter, and write it down somewhere. this is done with the amp turned on, and no rca signals and no speaker load. If you want to lower the DC offsets then i would look at replacement of the two main culprits, the input dual transistors, and the output Darlington devices. I would not try to upgrade any of the silicon devices unless you have the Engineering savy to resolve the issues you might be introducing to the amp design. I would only replace those things I understand to be bad with age and leave it at that. The main reason is this is a engineered device and major alterations require rethinking of proper operating parameters and unless you have the time and ability then your just putting yourself into a mess of trouble and headaches. Best of luck on the rework

30th July 2007, 04:44 PM	#6
guitarkirb diyAudio Member Join Date: Sep 2006	That's eexactly the type of info I was looking for! Thanks, Brian

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