I tried wiring up some IRFP450's but then it dident wanna work at all, weird oscillations and spitting out 5-8 volts.
However i did manage to get 200 watts from it at 1kHz unclipped, but as soon as i tried to add bias, it went into oscillation between 0 and like +8 volts and dident respond what so ever to an audio signal but as soon as power was turned off, the oscillation went away and the audio appeared.
The current cir is pretty much the same as one of Quasi's cirs but with 50V rails rather than 75V.
However i did manage to get 200 watts from it at 1kHz unclipped, but as soon as i tried to add bias, it went into oscillation between 0 and like +8 volts and dident respond what so ever to an audio signal but as soon as power was turned off, the oscillation went away and the audio appeared.
The current cir is pretty much the same as one of Quasi's cirs but with 50V rails rather than 75V.
Hi, Tekko, you must have a minimum voltage guard from drain to source between the maximum amplitude and the rails, 3 or more volts will help to reduce the Miller capacitor, as this capacitance grows when VDS decreases. Also is mandatory a very low impedance driver 1OHM or less.
Cheers
Arturo
Cheers
Arturo
After another low side fet failure i say this design just cannot work. Its barely even possible to stabilize it in simulation!!
I give up on this.
I give up on this.
I think i'll quit using mosfets for amplifiers and grab some MJ15024's on ebay instead like 10 for 20 bucks free ship and make a higher power version of the NPN amp i made in the past.
Sounds like another symptom of HF oscillation.
More instability. Maybe it needs a zobel network on the output, to provide HF loading even with no speaker connected.
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