I've been working on the power supply of an Orion 2250SX. It's pulling down the voltage after this resistor to 8v. I was wondering if this 68 ohm resistor is correct or if someone replaced it previously.
It's likely correct. Does one end connect to B+ and the other end to the collectors of the NPN PS driver transistors?
Yes, that is where it is installed in the circuit.
I've replaced all the drivers, the TL494, and several damaged drive resistors in an attempt to remedy this "issue". However, I'm unsure if this was normal behavior for this amp or not as I received it in pieces and non functional.
I've replaced all the drivers, the TL494, and several damaged drive resistors in an attempt to remedy this "issue". However, I'm unsure if this was normal behavior for this amp or not as I received it in pieces and non functional.
This amp uses PAM (pulse amplitude modulation) instead of PWM. The resistor voltage is pulled down by the 2N6488 regulator transistor as needed to maintain the target rail voltage.