65 Twin Reverb / Now Deluxe Reverb Reissue Hum

[plexi50]

I replaced my 65 twin reverb burnt out PT with a 65 Deluxe Reverb reissue PT. All under board changes were made to support this transformer with a 5 volt tap for rectifier tube use. Including standby and B+ positioning

I have developed a hum in this amp that increases as the volume is turned up. The plate voltage is  400VDC  @-37 on the grid. The power supply caps have all been changed.

I got a 65 Deluxe reverb reissue PT of Ebay for cheap ($32.00 w/fs). It hums like the PS caps are bad but are new as of yesterday. I have ruled out the bias cap and power tubes as the possible source. All cathode caps are good as are the voltages on them. I removed the reverb transformer source voltage to rule it out, as well as bypassing the choke with a 500r 5watt resistor. I have to test the channel coupling caps yet but at this point i believe i have a bum power transformer with a serious amount of hum. Any thoughts of anything i may be over looking?

[TIMBO]

Hey Plexi,Can an old PT (59years of age) be a source of hum and fizz if it is not well, although still able to pump out the designed volts???

[sluckey]

Does it hum on both channels?

[plexi50]

Does it hum on both channels?

Yes both channels. But the Vibrato channel is much louder and is the dominant hummer. Hum is present with volume pots at zero but is quickly amplified with volume rotation. 

[plexi50]

I got around to do some more testing today on the PT i bought and it is bad. The heater filament winding is burnt and is black just under the plastic wrapper on this PT. I could feel the PT vibrating with my hand and hear it as well. That will teach me to not buy another reissue PT.