punch amp PS fet subs

[ian33]

I am not sure what model this amp is.It has two mosfet in the power supplymtp75n05dh .i have irfz44n and FQP65n06 which one will be a better sub?
The outputs are irf9540 and irf540 can i used buz272 and buz21 for subs?

PC3080-E

[ian33]

PIC

[Perry Babin]

All of the transistors you listed as subs are rated lower than the originals. The reliability may suffer if they're used.

The BUZ transistors you listed were used in some Rockford amps for a short time but I think they went back to the 540/9540. Maybe it was done because the BUZ transistors weren't as reliable.

[ian33]

ok thanks for the info

[seankane]

Originally Posted by ian33

I am not sure what model this amp is.It has two mosfet in the power supplymtp75n05dh .i have irfz44n and FQP65n06 which one will be a better sub?
The outputs are irf9540 and irf540 can i used buz272 and buz21 for subs?

PC3080-E

The board looks that of a X250.2.

I would replace the MTP75N05HD with IRF3205 and change the gate drive resistors to a 47 OHM in the power supply. Check the 4 P/S drive transistors marked 1A and 2A.

Perry is right on the BUZ fets dont use them. Use the IRF540 and IRF9540 much easier to find and cheaper and more reliable. Check the gate resistors and make sure they are within tolerance and also check the source resistors.

If you have DC present on the bridging terminals after these parts are replaced, let me know I will let you know what resistors to change.

If you have any distortion I can help you determine which SMD diodes are bad. Keep us posted.

[ian33]

ok i will wait for the originals because i dont want this amp to come back any time soon

thanks