EL34 PP Cathode Bias Build

[7string]

I have a PP EL34 cathode bias build pretty far along. I got a little creative adding things to the tried and true Fender and Marshall schematics. Stuff learned here or from Merlin's site. I was hoping to get a quick spot check of the power supply. It's my first time using a tube rectifier in a build. I have a set of nice old transformers and even nicer old tubes for it.


The transformers are from a Dukane 1U460A 30 watt P.A. PT is 360-0-360 200ma rated. 4.2A 6.3V and 3A of 5V heater. OT is 6.6K primary with 4 and 8 ohm secondary. 30 watts. Original tubes are 2 x 5881. With a 5U4GB rectifier should be around 460V B+. 360 x 1.414 - 50 for the 5U4 drop. The Dukane schematic shows 432V while apparently using the 127V primary tap....?  PT primary has a tap for both 117V and 127V.


In a couple of similar recent threads here, the goal was 400V B+. Should I add some resistors the the plates of the rectifier tube? Another supplier has 25V zener diodes that can drop 40V, getting me down to around 420V B+ I'm hoping to keep the power down and not beat up on the output transformer too much and would rather not have to run the variac full time.


The preamp is the typical Marshall / 5F6A style. I have the 25V balanced speaker taps hooked up. Is there a good way to pad this down for balanced line level?

[shooter]

Have you powered up and measured or just done math?
the data sheet I looked at showed 450VDC for cathode biased so you might be fine with normal loading.

[7string]

I have not powered up yet. The wiring is about half way done. Thanks