Elrog 300B vs Takatsuki 300B tubes

The Elrog has a different internal impedance, gain and filament type to a conventional 300B. Internal impedance (resistance) is approx 900R vs 700R, gain is higher than a standard 300B and the filament is thoriated tungsten type vs oxide type. It will give less power than a standard 300B under the same conditions.
Elrog recommends to use the tube into higher impedance output transformer loads than a conventional 300B because of the higher internal impedance.
It can have a problem in an amplifier that was designed around 300B specs as it did in the case I mentioned. Problem = mismatch and sound compromise.
Voicing/sound of the tube is different from "standard" 300B but this could be either good or bad, users can decide for themselves.
In absence of proof that it works in a particular amp, like with Franks as we have here, or when one has no possibility to just get a bunch of tubes and hear them in his own amp, it could be wise to contact the amp designer for advise. More experiences similar to the one with Franks will tell the story eventually.

The longer I've live with and listen to the Elrog ER 300b the more I recognize how wonderful this tube is. The past few weeks I've been able to listen to quite a bit of music and it has been a truly enjoyable time. The sole purpose of Elrog it seems is superior emotive provocation. They simply connect me thoroughly and deeply into the musical soul. I've sat at home and played CDs all the way through and then replay them. I listen to songs three times in a row, it's that pleasurable. These tubes offer such a natural, fully developed and realistic tone/overtones that I'm just completely pulled into the listening experience. They really do everything in an excellent manner across the musical board.

I was at such an exalted level of contentment with my EML and Takatsuki, I'm actually surprised the Elrogs have taken my music listening to a higher plane( to this degree). As these tubes accumulate playing hours they just continue to improve. This is so satisfying because straight from the box they sound exceptional. I truly hope that the Elrogs will work in the vast majority of 300b amps as well as they do in my amplifier. This has been a sublime experience for me.

Lak,
They're 1099.00 USD pair. I bought mine at tubesusa.com. Demand seems greater than the current supply at this time.
Charles,

My recently acquired Elrog 300B replaces Psvane WE101D replica on Lampizator Big7 as output tube (Big7 has a switch to take either lower current or higher current tubes).

Initial impressions are very positive. Right now it is not as refined as 101D but it dwarfs 101D in every other areas. Sound stage expands dramatically; more details (and 101D was reported to be utterly detailed on Big7); better depths (but filled with information) and more holographic; more sense of realism on vocal.

I suppose that it needs burn-in to be more refined. Also my system needs tweaking. But certain details and depths already show how capable Elrog is. I am looking forward to trying them on tube amps sooner.

Thanks again to Charles and fellows for all the inputs. :)