recapping a Concert Lead

[kingnimrod]

I'm replacing some bad caps on this Concert Lead, and have run into a problem. The preamp caps were easy enough to get to and replace, but the power amp board is another situation.

Can anyone advise how best to disassemble the Concert lead to access the underside of the power amp circuit board? Or is there some helpful trick to get to it without pulling the board out? I don't think my soldering iron is skinny enough to fit through the vents in the bottom...

There are an awful lot of short leads connecting it to the case. I guess they didn't figure on this thing living long enough to need cap replacement....

[dheizer]

I will probably get blasted for the approach I took.  But given the age of the amp and the doubt I could remove and replace without messing anything up ...

I clipped the original leads right next to the caps.  Cleaned the leads and soldered the new caps to them above the board.

Simple, clean, broke nothing.   Just take care to not over heat the lead releasing it from the PCB.  If you do that you will need to remove the board and solder form the bottom.

[kingnimrod]

Is there any downside to doing it that way?

[george]

It looks awful if you ask me - amature night. Are the leads on the PA board soldered to the terminals? That makes disassembly difficult. I usually find suitable Molex type connector/pins and replace all the soldered leads. Disassemble test and replace caps and bias resistors, etc. Make sure the board is brought up to the latest service note mods and reassemble and test. I'm assuming the output transistors are okay.

[kingnimrod]

I decided to do it the "amateur" way for now but left the leads long enough to do it proper when I have the time.

Yes, lots of super-short leads from the output transistors, jacks etc straight to the board. There's quite a lot of spaghetti to untangle someday when I have the time. For now, replacing the 5 leaky caps has made the amp sound much better. I actually really like the distortion on it.