Favorite 300B: Sophia vs KR

Phil,
I must say I really agree with your observations. I `ve come to believe that ranking the performance of 300b tubes is not possible due to the many variables such as the ones you mentioned. Certain 300b tubes just seem to match better with different amplifiers based on circuit, passive parts,transformer, power supply design etc.

It can get expensive after a while trying numerous tubes in the higher quality range. If I come across a AVVT,EML or other highly regarded 300b for a reasonable cost I`ll give them a try. Otherwise the Shuguang Treasure is a wonderful mate with my Coincident Frankenstein, so I`ll leave well enough alone for now.
Best Regards,

I suppose the notion implied in my initial reply here, but left unsaid in a direct sense, should be expressed unequivocably:

The differences between power supply capacitors in an amplifier have, in my long experience making this change in push-pull tube and SET amps, been greater and more musically influential than the differences realized between any two alternative tubes. That's right, and I'll say this power supply cap difference is, further, much greater sonically in SET amps than in push-pull. Now, I'm not talking about mods that change the total power supply reserve in total capacitance. I'm citing changes in electrolytic capacitor construction between brands (or models in the same brand), that leave the total power supply reserve quantitatively unchanged from stock. I had the same experience with recapping my 845 SET amps.

It's not a convenient plug'n'play change like tube rolling, so not DIY accessible for most. But everyone should understand that recapping can introduce improvements (or if not chosen well, changes of the better OR worse kind) that can dwarf the results from changing tubes.

Another way to think about it: After my Audion Golden Dreams were recapped by Hovland, their performance with the cheapest, most prosaic $20 Chinese solid plate 300B everyone ships as stock, was better than their sound with my most exotic, scarce and expensive 300Bs prior to replacement of capacitors.

Bob also loaned me a simple Glow amp (5w, SE, EL84) that he recapped and made a few other small circuit changes to, as an experiment and to ask my opinion. I could get reasonable dynamics and SPLs from it on my 101db/w/m Zu Definition 2 speakers, and my Zu Druids. Within its clean dynamic range, the little Hovland-modified Glow wiped the floor with a number of $1500 - $5000 amps I put up against it, musically. And compared to a stock Glow, which is a well-liked tyke of an amp, the modded version was transformed, musically. No change in power tubes from among many I had on hand could remotely approach the difference.

Phil

Another example, numerous builders of 300b amplifiers say the type of driver tube chosen has as much if not more affect on the amp`s sound than the type of 300b output tube selected.

Charles, I kind of tube addicted, have many differ 6SN7 variations, such as ECC33, B65, CV1988 and 5692, so, no surprises here:-)

THX

Agree with Charles1dad, I have one amp that a 6sn7 change was more noticable than 300b tube rolling.