The reason for fusing each pair of transistors is in case one set or one transistor shorts,the fuse will blow and prevent the others from being grounded as well.
REALLY bad move.
Take out one transistor, you lose a bank. Think what that does to a combiner and the resistor around it.
Instead of the R dissipating 1/4 the power, it's now called on to diss half the power.
Other amps I've seen this done in ALSO end up burning up the combiners or splitters farther down / up stream in the amp because of imbalances.
If you're STUCK on doing this, then the proper way is to add a 'steering diode' after the fuse bank, and run a 4 input AND gate. One of the fuses blows, the AND gate output goes low, and disconnects the keying transistor.
2SC2879s DON'T SHORT OUT!!!! They blow wide open, usually on the emitter section, which would be the circuit to ground.
I'd leave it the way it is, run a single AGU or ATU style fuse (depending on the constant current draw of the amp), and be done with it. Get rid of the little glass fuse holders on it (my 500/667 both have 2, my sweet sixteen has 4, ALL are old enough to be serial #'d and 'turbo mod' editions). Run 8 or 6 ga out the back, and you are good to go.
As others have pointed out, you can improve the bias design, but all mine run stock, and have for almost 2 decades.
--Toll_Free
