Quick MTX Thunder 4250D question

[valterdaw]

I just returned to life badly abused 4250D amp. Will this amp survive with IRF540's in place of SSP45N20A's as there isn't even close to 200V on rails? Gate resistors was completely burnt too, replaced them with 47Ohm. Divers survived, pre-drivers failed too. Playing for an hour... but still scary 😱

 

[Perry Babin]

I've used IRF3415s in many of the older MTX amps that used the 45N20A FETs. They won't work in the larger amps because they can't handle the high rail voltage. I haven't had any failures in the smaller amps.

 

[valterdaw]

Thanks! Next time I put a parts order, I include them in the list. They seems to be rated at ~ x1.5 voltage and ~ x2 more current then 540's... So, there is good chance to blow 540's 🙁