AB International Support

I just get an 900a convention cooling. I´m gonna use to drive my 4 ohms subs Dj use. Do you think is necesary to instal the fan? How can i do if is necesary. Or if i use on fan outside direct to the heat sink?

I have an AB amplifier precedent series 600A. is it ok if I replace all the output transistor with MJ15003/04? it seems that is the only transistor available in our city. can I ask a schematic diagram for power supply only? thanks!!

i have an ab 1100 a , think i have gotten mix up with connecting the wires from the power transfornmer on to the power supply board. the original connector was damaged so I cut it off and solder on directly . but I think I mixed up the wires . Can you quote me the wire colours in proper series how they were connected. the amp seems to lost some top end power .

can you send ab1590b power amplifier schematic