Favorite 300B: Sophia vs KR

Which tube is better for you really depends upon the amp itself, and the extent to which you need specific voicing to compensate a sonic anomaly elsewhere in the system, or for tuning to your preferences. I'll go further in saying that even a given amp can be altered to completely change your perception of relative ranking of tubes.

For example, I have a stash of KR Audio 300B, Sophia perforated plate 300B and Sophia Princess 300B. I also have Vaic VV32BL, Emission Labs, Shuguang and others. While I did find the Sophia 300B to have a lot of top end "spray" and euphonic bass bloat, and preferred the stiffer, more revealing and dynamic sound of the KRs, a change to my 300B monoblocks also changed this preference.

I had my Audion Golden Dream PSET 300B monoblocks recapped by Bob Hovland (highly recommended). There was a small issue I needed diagnosed and took the amps to Bob. That issue was inconsequential but while he had the amps open I asked him to give me an opinion about whether he thought the power supply caps were worth keeping or replacing, given that the amps are a decade old and used heavily. Bob came back to me saying first that he is reluctant to change caps when an amp is already exceptional, and those Golden Dreams are truly outstanding. But he did believe that if I was willing to take some risk, a recap with Nichicon skinny cans would improve dynamics, definition and transparency further without degrading the tone density those high silver-content amps already offer.

He was right. The Golden Dreams came back better in all respects after the recap. I was curious enough, however, to run my 300B tube rankings again. The Audions recapped with Nichicons, the Sophia mesh plates lost their bass bloat and the aerosol top end lost the glitter and gloss to settle back to a natural frequency extension with even finer definition, while all of the midrange tone density was left intact. Bass is deep, tight and comparatively lean. Spatial dimensioning is convincing and scales appropriately to the music.

The Sophia mesh plates sounded beautiful in my Softone office amp but thick and syrupy in the stock Audion Golden Dreams, which is not remotely a quality of that amp. Meanwhile the KR Audio 300B sounded hard and spatially flat in the Softone but energetic, clean, lean and toneful in the Golden Dreams. After the Audion recap, The Sophia mesh plate is the more dynamically assertive tube with bass cleaner than the KR. The KR 300B now has a comparatively pinched soundstage width and it is dimensionally flatter than the Sophia.

There are a lot of factors in play on resolving this question. If you don't like a given tube, it may not be that there's anything generalizable that's deficient about the given tube. It may be that the tube just isn't a good match to your amp, as it came voiced from the factory.

Phil

Maxmad,
Thanks for your impressions of the Sophia tube. I`ve been completely happy with the Shuguang Treasure 300b for almost 2 years(sound quality and reliability). I`m however curious to hear an AVVT tube in my amplifier for comparision. Where are they available? Are they similar to the EML 300b tube?
Best Regards,

Dear Phil ( 213cobra ),

Many thanks for your post and even agree with it, I still having doubts about the price v.s. performance of Sophia's.

A good friend of my uses Royal's in his Zanden 7000 and after he tried AVVT C37, he started to hear all these things I have been describing more clearly.

Sophia "Mesh" been described, at least by many Cary CAD 300sei users, as match made in heaven. It took me not that long to realize that it’s not.

This is not the coincidence that Treasures, for example, didn’t do it for me either, Royal's are for sure better, but not vs. AVVT's and KR's. My KR's are tubular type, not in production anymore and have pretty much identical inside construction as AVVT 32BL, but in much smaller glass. Going to give them more listening time, KR's I mean, because they just stay in box after C37 arrived.

The easier way to describe my feelings is when Royal's are installed, I listen to Royal's, and when AVVT's, I listen to music.

There is another player in town, Takatsuki TA 300B, made in Japan with huge influence of Air Tight, here is the link where you can read some impressions

http://robertmusic.blogspot.com/2011/07/heads-up-coming-very-soon-takatsuke-ta.html

I don’t have anything to do with these guys and don’t know more than you, after you read the post from the link, but he seems to have the best 300B's around and even he didn’t compare them to everything he owns yet, but so far, he is very impressed with these Japanese...

THX

Hi Maxmad, I’m a happy owner of the Sophia Royals. I won’t disagree with your findings, which I couldn’t do anyway because you compared them to tubes I haven’t heard, but I’d like to say that 213 cobra’s points are very well stated. I’ve heard a variety of tubes demonstrate their sonic signatures very differently in different amps. I have a friend who is almost constantly modifying and tweaking his tubed components. After a modification, like cobra, he frequently winds up exploring his inventory of tubes and finding that a former reject now fills the bill.

A caution:
In a conversations with Sue from Sophia, she expressed great frustration with the number of Sophia counterfeits floating around.

Maxmad,

I can say that I would never recommend matching Sophia mesh (really, perforated) plate 300Bs with Cary amps. That's doubling down on the same basic sonic aberration. If someone likes that combination, one can't argue with that, but it would be a piling on of the same euphonic colorations that obscure what you value.

I have a pair of KR VV302 Blue glass that sound beautiful and bell-like in some amps, yet hard and overbearing in others. I also have the older KR Enterprises straight tube 300B with the AVVT-like interior structure. Those tubes have strong, vivid transient clarity, probably the firmest bass of any 300B I have, and good top and bottom extension. But in amps I've used them in, their spatial presentation is great in height and width but cmparatively limited in depth. I'm aware of the Takatsuki but haven't tried/heard them yet.

The Shuguang Treasure 300B has been unfailingly good in every amp I've heard them in, albeit a more modern sound than the typically vintage mesh plates. The current production KR AUdio balloon glass 300B nicely resolves a lot of the spikey differences between all these tubes. For me, a polar graph of its relevant sonic attributes is close to a circle in most amps. My mesh plates sound sensational in my re-capped Audion monoblocks, but I consider that a highly-specific match arrived at by chance since they didn't happen to be in the amp when the caps were chosen and installed.

I will say the Sophias were much less expensive when I bought them. But so were KRs. About $900/pr. now for the KR Audio 300B in the US. Partly a result of the dollar's slide and partly result of that company and its distribution chain realizing they had to own up to the true costs of running a business. In all this discussion, interesting that this decade's production of the WE 300B isn't in the mix.

Phil