i am working on this pioneer power amp and tis particular transistor doesnt seem to have a replacement all i can tell is that it is a FET. would any other FET work in its place? then a mini HI FI sony system detachable components. all powered by a amp unit. model MHC-99X. it has a a tranformer that takes in the power then sends it to another bigger transformer. the first one burnt out but i need to have it replaced. i would appreciated any advise. reply to mutabaazis@yahoo.com