I'm working an amplifier as in the thread title. Which FETs and gate resistor values are known good replacements?
I use IRF3205s. If the gate resistors survived, I leave them (10 ohms). If any need to be replaced, I use 47 ohm.
Thank you. I'll be using the 3205's and 47R resistors now. Half the supply survived, one rectifier died or was broken when someone looked at it and one side of outputs died as well.
I'm sure you know but these are some of the amps that actually do have bad capacitors that leak electrolyte.
Be sure to clean the board well with acetone and any black areas of board should be removed, even if in the vias (may mean that you'll have to re-route to reestablish connections).
The amp works now but I have one bank of the supply FETs heating up. The drive signals are not equal per side. They are good at the 494. Should I replace the drivers? I did not replace them as they read ok. I used SMP60N06-14's in place of SMP60N06-18's and used 10R gate resistors.
With no power applied, what is the resistance from leg 1 to leg 3 of the FETs on each bank.
Do you have the same voltage on the collectors of the NPN drivers of both banks?
Do you have the same voltage on the collectors of the NPN drivers of both banks?
I have the same voltage on the collectors. 1-3 resistance is ~80R on the side that stays cool and ~280R on the side that is warming up.
Found 270R resistor reading 80R on side that stays cool. This is the side that had failed and burned the 10R resistor to ground.