I have a Gentek servo amp made for Anilam in the early 1980's model GA4561, there are four transistors on this and I know at least one of them is bad. Transistor is a GTK45583, replacement transistor is GTK45578 at $90.00 each, anyone know of a suitable replacement for this transistor.
In my google search I have found these transistors and possible replacements, MJ10020, MJ10015 or MJ11032.
This amp is running a SEM MT30 servo motor, 75 vdc.
Any help I could get will be greatly appreciated,
Bruce