High B+ voltage in '60s Ampeg Gemini

[Beyer160]

I just finished a recap/retube/rebias of my '67 Ampeg Gemini II. I got a LOT of help from the fine folks on this forum, so I'm hoping you can answer me one more question- the schematic lists B+ at 430v, but after biasing at 65% dissipation I'm reading 503v. Now, my AC service metered at 122.5v and the front plate specifies 117v, but I don't imagine that'd account for such a big difference.

I'm using new production Tung-Sol 7591s (I was originally using JJs until I blew one- not their fault, I made an idiotic mistake) and can't find a datasheet, but the typical maximum plate voltage for 7591s is 550v. My question is, am I going to hurt anything running the plates so hot? Will I overheat the transformer, or should I just play the amp and stop worrying?

[g1]

Is this a schematic that is attached to the unit? Is it the stock power transformer?
The 6L6 version had B+ of 470V. It uses a different PT from the 7591 version.
The 7591 version shows 720VAC at the HV winding of the PT. What do you measure there?

[Chuck H]

Not sure why the schematic say's 430V at the "A" node. It does indeed also say 720V at the PT secondary. I just ran a simulation on PSUD2 based on the 720V figure. I adjusted for the 117V primary receiving 122V. Using the stated current with approximation for additional current it came out 505Vp. My experience with PSUD2 is that it's fairly accurate if programmed correctly. I think the 430V figure on the schematic is simply wrong. It wouldn't be the first time. I've seen innumerable schematics where numbers weren't adjusted after circuit changes were made. There are many BF to SF Fender schems where the BF used a GZ34 rectifier and the SF used a 5U4 rectifier and all the voltages match up. Which is impossible, of course. Most interesting is that the later SF amps that use the 5U4 are more accurate and the older, more revered BF design schematic voltages are dead wrong.

[g1]

On the schematic for the 6L6 version there is another voltage shown for the PT secondary but it is unreadable. That's the one that shows 470VDC for B+. The PT numbers listed are a little different, A for one version, B for the other.