Elrog 300B vs Takatsuki 300B tubes

P.S: A sharp-eyed reader may notice that at one point in my post just above I kind of juxtaposed EML's +/-5% tolerance with the 5.06 volt measurement Jet provided for the Sophia tube. I'm assuming that had Sophia provided a +/- tolerance on the 5 volt supply, the number would have been similar to EML's.

Best regards,
-- Al

Al - yes I installed a 100ohm resistor on one leg of the primary side of the filament transformer. And I did not change that value when changing from Eml to Sophia.
My vintage Stancor filament transformers are rated for 117v.
These trannies have a center tap so I can bias through it and avoid a bad sounding hum pot and still use a/c heat. I have no 60hz hum but if I put my ear to the speaker I hear what I believe to be a harmonic of 60hz which is 120hz. At least that is what I think I am hearing. The ELM tubes are so well balance a hum pot was not needed. But I was not so lucky with the Sophia which I could not use with out installing a hum pot.
When I removed those hum pots this amplifier came to life.

I would not feel comfortable running these tubes much above 1% which is 5.05v.

Thanks again, Jet. And kudos for the prudence and thoroughness that is evident in your approaches.

Best regards,
-- Al

I have addressed the over voltages and under voltages of my incoming power by using a PS Audio P-10 regenerator. I think it's a great thing. In my area, the power was measuring anywhere from 116v to 124v. I'm not associated with PS Audio in any way but the P-10 really works well.

Snopro, how many hours did you have on both pair of tubes when you compared them?
The reason I am asking is that it's crucial.
Takatsuki requires 150 hours of burn in. 100 hours minimum from my own experience with many pairs of these tubes in various systems. Until 100 hours they could be a hit or miss. When they are fresh they can even sound like 200 dollar tubes, nothing special. I'd say 150 hours is a must for any critical listening or comparison to other tubes.

I've asked about Elrog's burn time previously but I don't have an answer at the moment. Several people reported they sound good right from the start. But from all my experience with various 300B tubes all of them require burn in. PSVANE T2 requires 300 hours before critical listening or comparison to other tubes, Takatsuki - 150 hours. Elrogs probably some time as well. TJ Full Music SE may sound nothing special until 60-70 hours but full break in is longer. I don't believe Elrog has 0 hours to be broken in. I would give it 150 hours to be fair.
Also, amps that have manual bias, like one of my amps, should be biased for any new tube installed otherwise sound comparison doesn't make sense.