Repairing Soundstream Class A 6.0

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First off many thanks to those that have assisted me through privet e-mails. I have made a lot of progress on the most tortured amplifier I’ve ever laid hands on. The original owner completely trashed this amplifier. In my opinion the root cause of the damage started when the previous owner turned the potentiometers that sets the bias current of the output devices. These are the blue conductive plastic pots located by the preamp boards. I know they used this amp to drive multiple subwoofers too, but I found the high power/high current switch in high power mode. I’ve seen idiots do this before and it result in a damaged amp.

What I’ve done so far: Replaced the bias potentiometers because they had been turned past their mechanical limits and damaged. Replaced all the TIP102 and TIP107 output devices. Replaced several of the 1 ohm emitter resistors. Replaced several of the 1N5402 emitter diodes. Replaced the MPSA14 bias transistors. Made new L101 and L103 5.25uH coils because the originals were almost black. Replaced the four 1000uF/50V rail caps because three of the four were popped on top.

What I still need to do: I need to replace the FED16BT rectifiers. I can’t seem to find any replacements. Anyone have a suggestion for me? Also, I need to replace a few of the RFP50N05 Mosfets in the power supply. This appears to have been discontinued by the manufacturer. Is the RFP50N60 an okay substitute? I’m really concerned that the input capacitance of this device might be too high. The NDP6060 looks like a better substitute other than it is rated for 48 amps instead of 50 amps. What do you guys suggest here? I also believe one of the 85 C degree thermal switches has been cooked. Does anyone know the specifications for these thermal switches? It’s the one that shuts down the power supply when the amp gets too hot. Any help would be greatly appreciated. Thanks guys!

Rgs, JLH
 
Thanks I've done that. He is setting me up with some 2SC3067 as well. Seems like a very nice and professional person to deal with so far. I hope to get this beast working in the next month or so. I'm taking my time and pretty much pulling everything from the board one at a time and testing each component. Normally I would not go to this much trouble to repair anything, but this amp is too classic to not save.

Rgs, JLH
 
IT'S ALIVE! IT'S ALIVE! And damn does it sound nice. I absolutely love that warm smooth old school Soundstream tone. I wish somebody would start making these amps again just like they used to be. Now I just need to fix two Class A 3.0 and a Reference 200.
 
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