Early in my F5's life it was accidentally left on for a couple of days. When I had been using it the heatsinks had never gotten over 48 C but somehow during this couple of days something happened and the fuse blew. I found both output mosfets on the failed channel were now burned out. I had no speaker protection on it at the time but fortunately my speakers were switched to a different amp via a switchbox and weren't connected to the F5. After this I added the store's speaker protection board and lowered the bias from 1.3 to 1A after replacing the mosfets and source resisters. I haven't had any trouble with it since but definitely wouldn't go without the speaker protection again. And also, of course I'm much more careful that it doesn't get left on.
Thanks!While there isn't an official line on this if you are concerned then have a look in the diyaudio store. There is a PCB set for soft start + speaker protection (2 boards as a set) that will do the job. And you are supporting the forums if you do decide to buy.
Guess it had something to do with P1 and P2 potentiometers quality.
Not sure what you mean about the pots. If you're referring to me lowering the bias, I only did that to be safer, and run a little cooler.
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