Bassman 6G6B Power Transformer

[Jenkins]

Have a Bassman 6G6B i am working on and getting some high voltage readings off the PT.
Numbers on it are 125P7A, 606145

Out of circuit i am measuring 390-0-390. Bias and heater voltages are with in spec.

When i wire it in to the circuit, w/o tubes, and at the 1st filter node only. The voltage reading is 520.

I was expecting unloaded voltages more in the 345-360 for that model Bassman.

Any thoughts ?

Thanks in advance.

Jenkins

[passaloutre]

The B+ is 430 in the finished amp. Why would your unloaded voltage be in the 300s?

Are you looking at an original 60s Bassman or a clone?

https://el34world.com/charts/Schematics/files/Fender/Fender_bassman_6g6b_schem.pdf

[Jenkins]

The B+ is 430 in the finished amp. Why would your unloaded voltage be in the 300s?

Are you looking at an original 60s Bassman or a clone?

https://el34world.com/charts/Schematics/files/Fender/Fender_bassman_6g6b_schem.pdf

Original Bassman. Tube Chart says 6G6B

Measuring PT's in the past i have always saw most Fenders to be in a specific range according to amp model.

Would the specs on the following not be unloaded specs ?
https://el34world.com/Transformers/files/MOJO762.pdf

Thanks

[SEL49]

Out of circuit i am measuring 390-0-390. Bias and heater voltages are with in spec.

When i wire it in to the circuit, w/o tubes, and at the 1st filter node only. The voltage reading is 520.

That's exactly what you should read with no load. Calculated value is √2 x 390 = 551.5. Knock off a bit for cap leakage and meter loading and 520 becomes a very believable number. This is all normal behavior. Don't worry. Be happy.

Would the specs on the following not be unloaded specs ?
https://el34world.com/Transformers/files/MOJO762.pdf

The specs say the HT winding is rated for 354-0-354 @ 250mA. That's a full load rating, not an open no-load rating.