fixing a Rel Strata III subwoofer amp

[clived]

@geoturbo yes I can see C4 in one of your images. Interesting (and difficult ) that the value could be either 6n6 (if you're right about it being C5 in that schematic) or 4p7 or 4n7! @davidsrsb if you've got insight into the most likely and / or criticality of the value that would be great.

 

[clived]

Rel C4.jpg
Hopefully that's worked?

 

[davidsrsb]

There seems to be consensus to change the big resistor to 15k 3W
I am still not sure which capacitor your "C4" is
The capacitor across the power resistor 6n8 could be anything between 4n7 and 10n, not fussy, but 100V or more, COG dielectric
It might also be the 33pF in the schematic. Nobody has photographed the PCB well in that area to show the connections.

 

[clived]

So we've bitten the bullet and are going to try a 10n and see what happens - what's the worst that can happen I'll report back as it will I guess add to our understanding of how the diagram maps to the Strata III board.

 

[clived]

Alas - not successful so I'll be buying a BK I think. But will have an excellent condition Strata III cabinet and driver for sale!

 

[Puggie]

Possible solution:

https://pinkfishmedia.net/forum/threads/bk-electronics-bsbp275-subwoofer-plate-amp-new.277932/

 

[clived]

Thanks @Puggie - too much of a faff for me but might make a good project for someone if they want my sub with dead amp too!