So I have 2 in pretty poor shape Altec 1590A power amps that I cant find a schematic for. I can find the 1590E but from looks that 1590E is updated version and alot of what i need to know is not in the updated version of the 1590A. From what i can tell this is a class A amp that can push 200 watts due to the transformer. I tested all the output transistors and they all work but the driver board is a mess and uses germanium transistors that are transformer coupled from the first stage to the next. I can see why these amps are kinda known for lacking fidelity because of this driver board. My idea is to replace the driver board with something more updated while staying class A. My idea is to use the JLH amp board to drive the output stage. Im not sure how off I am on this idea I am kinda a electronics noobie and i might just be way off on how this all works. Just need some general help and pointing in the right direction
It's for drive-in theaters, also factory and civil-defense apps where utility power may be lost yet announcements must get through. (Put a big truck battery behind it.)
It's sure not class A, not even close.
It is NOT like any modern amp because of the transformer OUTput. This change ripples back to the driver and the supply rails.
This size of transistor amplifier, when repairs go wrong, they go expensively wrong instantly.
It's sure not class A, not even close.
It is NOT like any modern amp because of the transformer OUTput. This change ripples back to the driver and the supply rails.
This size of transistor amplifier, when repairs go wrong, they go expensively wrong instantly.
It is class A. It has a 0-31V Supply voltage and a pure NPN output stage. Its actually a dead simple amp with 8 2N3055 on the outputs. The Transformer brings efficiency up from 25% to about 50% for class A operation. It still draws a good amount of power and heat.