Hello everyone, found plenty of useful information on SoundStream amplifier problems and thought I'd add mine to the mix 
It's a reference 414s, and I have diagnosed two problems:
-RCA input grounds and signal show 10V difference with amplifier ground.
-3 of the 6 RCA grounds are common, the other 3 are open circuit from each other.
Any help much appreciated
Greg
It's a reference 414s, and I have diagnosed two problems:
-RCA input grounds and signal show 10V difference with amplifier ground.
-3 of the 6 RCA grounds are common, the other 3 are open circuit from each other.
Any help much appreciated
Greg
Have you checked with soundstream to see if a schematic is available?
If 2 of the RCAs that are common are outputs, that may be normal. One RCA input ground and the two outputs may be connected directly to the secondary ground. The other 3 inputs may be isolated with a 1K ohm resistor.
The 10v offset could be due to an open/missing resistor that connects the secondary ground to the chassis ground (if I'm not mistaken). It may connect the secondary ground to the signal ground. The schematic would be very helpful here.
If 2 of the RCAs that are common are outputs, that may be normal. One RCA input ground and the two outputs may be connected directly to the secondary ground. The other 3 inputs may be isolated with a 1K ohm resistor.
The 10v offset could be due to an open/missing resistor that connects the secondary ground to the chassis ground (if I'm not mistaken). It may connect the secondary ground to the signal ground. The schematic would be very helpful here.
Hi Perry,
thanks for your response.
I have emailed Soundstream tech-support and not got a response yet. I described the problem and asked if they knew what it could be.
If they respond, I'll ask for schematics.
On the subject of RCA grounds, there are four input terminals (2 channel left+right) and two line output terminals for daisy-chaining amps - so six sockets in total.
Three of the input socket grounds are common, the fourth appears "unconnected", it's an open circuit as far as I remember.
The remaining RCA input and two outputs don't appear to be connected either.
The two outputs don't even share a ground
Have you taken a soundstream amp apart ? I have only gone as far as the casing and not taken the PCB off the main heatsink.
There is a conductive material where the transistors touch the heatsink, I am worried that taking the whole amp apart will disturb this. Any thoughts on putting the amp back together properly would be appreciated
Thanks again
Greg
thanks for your response.
I have emailed Soundstream tech-support and not got a response yet. I described the problem and asked if they knew what it could be.
If they respond, I'll ask for schematics.
On the subject of RCA grounds, there are four input terminals (2 channel left+right) and two line output terminals for daisy-chaining amps - so six sockets in total.
Three of the input socket grounds are common, the fourth appears "unconnected", it's an open circuit as far as I remember.
The remaining RCA input and two outputs don't appear to be connected either.
The two outputs don't even share a ground
Have you taken a soundstream amp apart ? I have only gone as far as the casing and not taken the PCB off the main heatsink.
There is a conductive material where the transistors touch the heatsink, I am worried that taking the whole amp apart will disturb this. Any thoughts on putting the amp back together properly would be appreciated
Thanks again
Greg
If you have 10 volts on your RCA shield you have some real issues in that amp. I am sure the 10 ohm secondary to primary ground resistor is burnt up. But still you should not be getting anything over 500 millivolts when referenced to ground of 12 volts.
I would say by your info that there is some damaged components in one or more of the channels causing this. And all the RCAs shield should read zero ohms between each other, so there maybe a issue there also.
These are symptoms of a more complicated issue inside the amp. You must find the main issue fix that, and also fix the symptoms that the original problem has caused.
SS should release the print to you , I have seen them do that before. If not contact jandrelectronics on e-bay. Jaime worked for them for years, he also has parts.
Good luck and cheers
I would say by your info that there is some damaged components in one or more of the channels causing this. And all the RCAs shield should read zero ohms between each other, so there maybe a issue there also.
These are symptoms of a more complicated issue inside the amp. You must find the main issue fix that, and also fix the symptoms that the original problem has caused.
SS should release the print to you , I have seen them do that before. If not contact jandrelectronics on e-bay. Jaime worked for them for years, he also has parts.
Good luck and cheers
The outputs should definitely share a common shield ground. Recheck the connectors to be sure you have the correct readings. You need to check this on ohms, not diode check.
The kapton film is tough and difficult to damage. Try not to lift it. If you do and debris gets in the area under any of the heatsink mounted components, you'll have to remove it, remove all of the old heatsink compound and apply new compound.
When you remove the board from the sink, you need to screw all of the set screws down before lifting the board. When reassembling it, you need to make sure all of the LEDs are in their holes. It's annoying to find that one didn't fall into place AFTER you've reinstalled all of the screws.
You'll also need to check all of the switches for intermittant operation before reassembling it.
There may be one washer (holding the board to the sink) that has a rubber insert. If so, it needs to go back in the same location.
The kapton film is tough and difficult to damage. Try not to lift it. If you do and debris gets in the area under any of the heatsink mounted components, you'll have to remove it, remove all of the old heatsink compound and apply new compound.
When you remove the board from the sink, you need to screw all of the set screws down before lifting the board. When reassembling it, you need to make sure all of the LEDs are in their holes. It's annoying to find that one didn't fall into place AFTER you've reinstalled all of the screws.
You'll also need to check all of the switches for intermittant operation before reassembling it.
There may be one washer (holding the board to the sink) that has a rubber insert. If so, it needs to go back in the same location.
Thanks again for the input guys
No response from SS yet
I have disassembled the amp again for a closer inspection, and can't see anything obviously burnt/broken/etc...
Where would the 10ohm resistors you mention ? Close to the power supply ?
I'll try the chap you have mentionned on eBay
Thanks again.
No response from SS yet
I have disassembled the amp again for a closer inspection, and can't see anything obviously burnt/broken/etc...
Where would the 10ohm resistors you mention ? Close to the power supply ?
I'll try the chap you have mentionned on eBay
Thanks again.
If your amp has the 10 ohm resistors (not all do), they could be anywhere on the board but are likely to be along the line where the power supply section meets the audio section. They are generally 1 watt resistors.
Did you re-check to see if you had the inputs and outputs conused? It's VERY strange not to have continuity (~0 ohms) between the shields of the output RCAs. Test continuity between the frames of the RCA connectors (the metal part that the threaded barrel is pressed into). Sometimes the threaded part has a poor connection to the frame.
Are they sending the schematics via snail mail or email?
Did you re-check to see if you had the inputs and outputs conused? It's VERY strange not to have continuity (~0 ohms) between the shields of the output RCAs. Test continuity between the frames of the RCA connectors (the metal part that the threaded barrel is pressed into). Sometimes the threaded part has a poor connection to the frame.
Are they sending the schematics via snail mail or email?
Perry Babin said:
I'll have a look again tonight.
The two RCA out are grounded together with one RCA in. The other three RCA in are not connected
I have tested continuity on the circuit board, as well as the barrels.
email, sent an email at 15:50 Californian time yesterday, kind of hoping for an immediate response since I spoke to the chap only minutes before, so far, no reply
Perry Babin said:
No I didn't, my h/u suddenly died, took it apart, found some burnt and broken PCB tracks, traced them to the line-outs of the h/u and decided to check the amp's line-in just in case.
I am glad I did since it seems the next h/u might well have suffered the same fate !
Jaime (Jandrelectronics on eBay) has come back to me and made the same suggestion (floating ground). Apparently, only channel 2 is grounded, the other RCA's are grounded via a 1ohm resistor. He's asked me to check a few things (337 and 317 voltage regulators to start with) and will get back to me.
I've also received a useful response from Soundstream
HELLO; THIS IS NOT NORMAL AND THE AMPS NEEDS TO BE REPAIRED. COST TO REPAIR YOUR AMP WOULD BE A FLAT FEE OF $150.00 AND COMES WITH A 90 DAY WARRANTY. IF YOU WANT TO SEND YOUR AMP IN FOR REPAIR, PLEASE GIVE US A CALL AT 1800-724-1377,SO WE CAN ISSUE YOU A RA-REPAIR NUMBER. THANK YOU
So no schematics from them then
Without remote voltage applied to the amp (only B+ and ground connected to the poweer supply), measure the DC voltage on channel 2 shield (or the output shields). The black meter lead should be connected to the power supply ground. If there is 12v present, the transformer is shorted. You may want to twist/move the transformer slightly while checking the voltage because the short could be intermittent.
Perry Babin said:
Tried this to no avail... same with remote voltage applied.
However, and here is the most frustrating thing... the problem has disappeared... on the test bench at least.
All powered up with a lab power supply, bare board on the bench, all checks out fine.
Put the board back into the casing, and all is fine.
Wiggling the transformers makes no difference
. Now, I don't know what to do... electronics don't fix themselves... if I put it back in the car, chances are the h/u will eventually fry itself.I don't want to throw the amp away
I still suspect the transformer. If you pushed on it, you may have made enough clearance between the lead windings and the rest of the windings to break the connection. The problem is almost always between the lead windings (the ones that connect to the board) and the remainder of the windings. The cores are not well supported (particularly in the ones that have the transformers in a cutout) and they cause the enamel to wear through when the windings wrapped around the core rub on the lead windings.
If you can't find the short, I'd strongly suggest that you apply epoxy between the lead windings (where they begin to wrap around the core) and the main body of windings. Try to work the epoxy between the windings. If possible, work an epoxy soaked piece of paper between the windings.
When you reinstall it, I'd strongly recommend that you fuse the shield connections between the amp and the head unit. If the short returns, the fuse will open instead of the traces in the head unit.
You can fuse the shields by using a short RCA extension cable (male to female) and breaking the shields in it. You would use 1 amp fuses to reconnect the shields.
Other than a shorted transformer, there are few things that can cause the amp to burn the head unit's shields. The only other thing I can think of is a speaker wire shorted to ground but that would not have caused you to have DC on the shields after it was removed from the vehicle.
If you can't find the short, I'd strongly suggest that you apply epoxy between the lead windings (where they begin to wrap around the core) and the main body of windings. Try to work the epoxy between the windings. If possible, work an epoxy soaked piece of paper between the windings.
When you reinstall it, I'd strongly recommend that you fuse the shield connections between the amp and the head unit. If the short returns, the fuse will open instead of the traces in the head unit.
You can fuse the shields by using a short RCA extension cable (male to female) and breaking the shields in it. You would use 1 amp fuses to reconnect the shields.
Other than a shorted transformer, there are few things that can cause the amp to burn the head unit's shields. The only other thing I can think of is a speaker wire shorted to ground but that would not have caused you to have DC on the shields after it was removed from the vehicle.
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