Rockford Fosgate Punch 250m2

[seankane]

Hello everyone.

I purchased this amp awhile ago and it works great and sounds amazing!!!

I pulled the back cover and it looks like it is a virgin board and has never been repaired. The warranty seals were still in tact.

I found a cap soldered to leg 9 and 10 of the LM339 to one side of R20 resistor. I have had several of these apart and have never seen this before especially from the factory.

Can anyone tell me why this would be done and if any benefit or downfall?

 

[Perry Babin]

It appears to be there to damp the reaction to high voltage spikes. The schematic lists it as a 0.01uf and designated as C10. If there is no C10 or there is no other cap connected across those points in the circuit, it was likely a mistake (they unintentionally omitted it in the layout). If the cap in the amp is much larger in value, the original may not have been sufficient.

 

[seankane]

Hey Perry could I trouble you for the schematic for this amp?

I have worked on several but never had a schematic, maybe you have one?

If so that would be great, thank you.

Also one more question D100 and D101 the IN5336B's are not installed in this amp. It just looks like they were never there. Should I be concerned with these missing?