Marantz PM-57 Amplifier

[daveyboy11]

Hi there. I have a Marantz PM-57 amplifier which stopped working whilst being run fairly hard. I have diagnosed a faulty mains transformer and am trying to source a replacement. I am having a hard time locating a spare. Does anyone have any suggestions where I can get my hands on one or a schematic so I can work out what voltages are required or failling this can tell me what output voltages the original transformer gave to replace it? Is there any advantage to me fitting a toroidal transformer instead?
If you could help me out at all I'd be eternally grateful.
Regards,

[Nuuk]

Are you absolutely certain that it is the mains transformer and not a bad connection somewhere? If you have crimped terminals on the mains lead to the power switch etc, try cutting them off and replacing them with new ones.

[daveyboy11]

Hi there. Thanks for your reply. Yes I tested the output of the transformer and it is giving nothing. I am guessing it has overheat protection (thermal fuse of some sorts) which has blown.

[Nuuk]

Yes I tested the output of the transformer

Nothing in, nothing out is the key here! Please do what I suggested, you may be in for a pleasant surprise!

[Thomo]

The boards in these amps are the same as the ones in the later PM66/PM6010.

The transistors are different and some components are also different. But given the huge gains experienced by changing the tx in those amps, I would find the largest va that you can. I cannot remember what voltage they are, but if you find the pm66 mod thread and ask there, I'm sure someone else could tell you.

cheers,

Lee.