5A3 Voltage

[angelodp]

Hi, I am looking for a schematic for the 5A3 that has voltage readings.

Thanks

[Phil_S]

You might attempt to contact Rob Robinette a sometimes poster here. He might know something. I think his handle is RobRob. Regrettably, PM here only works if the member logs in and checks his mail here. No messages are sent to the member.

Rob's got a page on the Fender Deluxe. https://robrobinette.com/Fender_Deluxe_Models.htm
There is an email contact at the bottom of his home page: https://robrobinette.com/index.htm

[Stevem]

If I recall right, the PT outputs about 300 volts to the unloaded 5Y3 recto.

[angelodp]

Thanks guys, will do.

[sluckey]

There are two different versions of the 5A3 and they use different tubes.

https://www.youtube.com/watch?v=PlvsOA-_qBk

[Colossal]

Here's the money shot showing the power amp voltages from Uncle Doug's 5A3 video:

Plate Voltage - Cathode Voltage = 334VDC
Cathode = 18.09VDC across 255Ω bias resistor
352VDC on the plates
70.94mA for two tubes, 35.5mA per 6V6
11.85W of dissipation

5A3 Power.png