Hot Rod Deluxe PCB Jacks

[roadkingbluzs]

Thanks . Will do a little research first.

[martin manning]

Per the scematic, the +/- 16V supply is regulated by a pair of Zener diodes, so the relays and op-amps will get the correct voltage either way. Resistors of either value will see same voltage drop from the +/-48V at the rectifier to the Zeners, 49-16=32V. That means 470R resistors will be dissipating 2.2W, and 360R resistors will be dissipating 2.8W. Fine for 5W resistors either way, but the 360R's will actually run hotter. I think the fix for the failing solder joints is more about getting the resistors up off the board to improve airflow and keep the leads from getting so hot. If there is a service bulliten recommending replacement with lower values, it must be related to voltage regulation.

[roadkingbluzs]

I am going to study schematic a bit to understand this more. Still trying to wrap my head around theory. Great.!