Recently acquired these units as a trade for services. They had been sitting for many years so the first step was to test all of the tubes, which all tested good. One unit has a pair of GE 6550 power tubes and the other has a pair of British Genelex Gold Monarch KT88 tubes. In both cases the output tubes tested within 400 micromhos of each other and within 5 milliamps of plate current on my Hickok 539B tube tester.

Next step was to replace all of the electrolytic capacitors in the units, even though they seemed to function fine after bringing up both units slowly with a Variac over several hours. I also replaced the rectifiers with heavy duty silicon units, along with replacing the original selenium bias rectifier with a silicon unit and the proper value dropping resistor. All of the coupling caps are quality units which all tested good on my capacitor checker. These type typically last for a lifetime as opposed to the older wax units.

Picture showing new caps with higher voltage ratings and new rectifiers.
New caps were slowly brought up to operating voltage and fixed bias resistor value was changed to reflect the lower voltage drop of the new silicon rectifier versus the original selenium rectifier.

Units completed with new front panels, retested for output power, proper bias, and sound quality, and reinstalled back into their original Bud rack cabinet. I will be putting them up for sale shortly with the cabinet.