substitutes for irf640/9640?

[DcMaN]

Hey i was just wondering, i have a amp here that has irf640/irf9640 is it possible to replace them with irf540/irf9540?

[richie00boy]

You should be Ok as long as the amp rails are under 50V. It's not ideal, but if you are stuck it should work.

[1moreamp]

You should try to stick to original engineering and parts unless you want to deal with unpredictable results.
Plus 640 and 9640 are fairly cheap everywhere why ask for more trouble by down grading to a lower voltage part.
The maker felt it needed the higher breakdown voltage device in the first place perhaps their reasoning was valid.

Sometimes a simple repair gets hard when you put in lower grade parts

[Perry Babin]

I agree, use the originals if available.

What amp is this?

[m4ick]

Avnet has them.

I just bought some the other day and they work fine.

[DcMaN]

I know, i always try to use original parts, its just that i dont have any place local that stocks these so i always end up having to order them. The amp is a Memphis 16-MC500D

[1moreamp]

You had better use the correct part in these amps. I have a couple I fixed here at my bench right now, so I am not guessing on these, they run pretty high rails inside these D class amps...