Favorite 300B: Sophia vs KR

Gsm:

I am also very curious at your findings of the Takasuki 300B vs. the RP. I second the results of the Psvang vs. the RP....the Psvang is not near as complete or refined and I would consider it a big step down from the RP. The RP has a very refined smooth/sweet top end and midrange liquidity yet portrays very high resolution done in a very musical way that draws you into the music. This is a tough combination to get right but it seems to do it with holographic imaging to spare.
I do not have enough hours on them (50 and counting) to make a determination on the reliability but so far so good on my Border Patrol S10 EXD fixed bias amp.

GSM, I will also anxiously await your comparison and I think all we can ask is your honest comparison in your system as you know it and how both tubes relate to the listening pleasures you admire.
We will all have to relax and make sure you feel that you have spent enough adequate burn in of the new tubes to have a final thought....since my RP tubes changed after 100 hours of burn in I recommend you take the time needed to make your comparison since we will all be here a day or two longer I hope.

GSM
Thanks for the effort in trying. I am sure your tubes are sold but if not email gwalters@charterwest.com. I will own both Takasuki one of these days along with my RPs. I own the Border Patrol S10 EXD with fixed bias so tube biasing is not a problem. In the mean time I will await for more drama to unfold.
gwalt

Now that there has finally been some comment and comparisons done on these two heavy weight tubes I would like to add my two cents since I own both of them now and have done a good deal of listening to both. The comparisons were done in a Border Patrol S-10 EXD amplifier with dual power supplies through Edgarhorn Titan l speakers heavily modified @ 107db efficiency.
Since this amplifier is a fixed bias and adjustible I set both tubes up at .685 MA (The recommended is .68-.70 MA from the amp. designer) and gave them some 50 hours of listening before a recheck of bias....more later on this.

I will try to catergize what I think most audiophiles classify would find important and give you a descritption from there.

Nuetrality: I give the nod to the takasuki as it extends top to bottom with no emphasis anywhere. The RP has very slight warm character in the midbass like you can hear the carbon plates at work. They pull this off however by still giving you the full performance and extension and both are as smooth as butter.

Holograpic imaging: I thought the Takasuki was a little wider in the soundstage with greater front to back imaging. The RP was farther back to begin with and a more laid back character. In my set up it was like the Takasuki is row F and the RP is row M. This differs from Charlesdad comparison in my system....welcome to audio as both systems differ as well as our hearing.

Musicality/Tone definition: The richer sounding tube to me was the RP but it is not night and day but I could characterize the Carbon plates of the RP. They still give you the full performance however just that a bit of extra fullness there if you need it. The Takasuki was simply the more nuetral sounding of the two.

Quietness and definition/resolution: The nod goes to the Takasuki as there is simply more air and definition around the performance....things are easier to depict and it could be because the backround is simply quieter who knows. Both tubes are great here however as compared to the Psvang/BT and EH tubes I have encountered.

Since I was curious on rechecking bias on the new tubes I rechecked after some 50 hours or two weeks of listening and found the Takasuki at exactly the same bias I began with .685 MA! The RP had moved lower and needed to be reset again. In the end I find them both very stable but the Takasuki was something special there as I have never experienced such stability. Maybe they liked my amplifier better who knows but thought I would share.

In the end I doubt you will be disappointed with either and would classify both extremely fun to listen to in there own ways and could live with either and find myself very fortunate to own both. I like the Takasuki to be a better fit in my system but your MMV. My suggestion is to save up and buy them both as it is the only way you will surely know!

I have limited time to join in the fun of the forums but from this please realize both tubes are leaders in their class and your system will likely bring out the best in either and you will have to be the judge from there.

I would also like to thank you for all your learning experiences and want to thank those who commented on my two cents. I will mention I like a lot of various female jazz such as Jennifer Warnes, Hollie Cole, Diana Krall, Melody Gardot, and Patricia Barber among others. On the male side I listen to many of the stunning recordings on the German Stockfisch label. To really find the soundstage I listen to classical and live recorded Russian choral music that are well recorded.

For the past 3-4 years I have been listening to 45 tube amps. (Jeff Korneff and Yamamoto A08S) because I firmly believed that a 45 tube (on the proper matched speakers) had the most natural tone and timbral accuracy of any of the triodes and in ways they are king at low listening volumes with limited power reserves.

However I am happy to conclude that the RP and Takasuki tubes sound much the same as a good 45 only on steroids. This is as high of complement as you can pay IMO.

What you get here is pure music and no areas to really criticize. In a properly designed amplifier these tubes are very tonally accurate and simply make the speakers disappear with ease. Not much else I can add except I wished they were not so darn expensive as my entire stash of 45's (7 pairs of NOS) were about the price of one pair of these 300b's. Whoever said being on steroids was cheap!

I agree with your findings also Charles1dad and thanks for all of the time you have put into this thread. Now that we have praised both of these tubes (and the truth be known) I wonder how the sales will drive the prices?

Thanks to all of you for your participation in this valuable thread. I am enjoying all of the comments and posted some earlier and will only say the Takasuki's are still my favorite with my amp. thus this comment is a bit off course and adds nothing to the fact of any further sound re-inforcement of these tubes.

Since we are all talking so much about the high cost of these tubes (along with the great sound) I will share with
you that my amp. designer (Gary Dews from England) gave me a hint that in his experience (and some of his long-time customers) he has noted an "increased" life to any 300b tube if you have an adequate way to cool them......obviously this makes total sense.

He suggested I pick up a low voltage/low noise fan that is capable of moving some air from the back of the amplifier and blow onto the tubes. I thus have purchased a small computer tower type fan (4 X 4 X 1 inch) that is rated at very low noise and plan on configuring it (in an easily removeable way) on the back base of my amplifier to blow air across the tubes when in use to move air. My little fan is rated at 33DB noise and 56CFM so we will see. I also picked up a 72 inch power cord that has an variable speed control for the fan.

Everything I have read states you have to be 3-4 feet anyway to even hear it running so we will see. The key hear is to get one that moves some air yet is rated very low noise and they are out there and mine will be adjustable.

No offense but I paid $20 bucks for this experiment and what could it possibly hurt? The little fan is supposed to be here soon and if nothing else it will ease my guilt of trying to extend the life of the 300B tube which is a topic in itself.

Some of you might think I am lost in the wilderness but maybe some of you have already experimented and it would be nice to know if so.

Charles1dad:

Thanks for the reply. I forgot to mention I have no real detection of running the tubes hard in the circuit as I think both of our amps. qualify as over built.

My transformers do not even get warm to the touch after 12 hours but the base of the tubes are warm and I think the theory is if you keep the tubes cooler you tend to re-tard the damages that internal heat can do.

I run the tubes @ .68ma which is considered approximately 65%-70% of full output.

I have heard different stories that tubes can still test strong after many hours (5000 plus) but loose their life in sound. I think I have discovered this with a pair of 45 tubes that were driven "softly" by a Korneff amp. yet sounded dull (on horns) after 2 years and logging many hours. A quick check in the Hickock 600A showed a lot of life but a change to some similar tested pair brought back the life in the music. The tubes with a lot of hours still test swell today but sound soft. Not only this but some designers will tell you the same...so I think you have to trust your listening skills and have another pair to compare.
In my heart I have to believe if you get 5000-8000 hours on output tubes you might be doing good.....40,000 hours is non-sense IMO. I am glad that Phaelon mentioned this because I had no where near 150 hours on my RP tubes...maybe they are asleep yet?
My little fan idea gave me a piece of mind that it is the best I can do to extend the life by trying to cool the tubes. Once I connected the variable voltage cord and turn to ultra slow speed I cannot detect the fan running at 2 feet away but the tubes run much cooler...on the outside at least.
There are so many experiments going on in my man-cave I cannot keep up with them all.

Charles1dad I agree with my NOS 45's you never know the history and only test how high the microbos/ma rating goes on your tester and if they are quiet with no shorts etc. I am only relating my experience with 45's (not 300b tubes) purchased on EBAY @ $100-$150 per pair on a simple made tube in a simple circuit from sellers with stellar feedback and experience with tubes. I had put a lot of hours on the ones that sounded soft in the end and got my $100 out of them. Current production 45's I tried were quickly sold off in favor of NOS.
I think you have a lot more to risk in the NOS 300b tube with WE prices (not for me) and lack of any warranty and totally agree on that. For me I guess I would like to hear more from someone who has the extra long 300b tube life chime in with their experiences. I had two long time manufacturers tell me the same thing. Anyone out there with over 10,000 hours on a 300b tube that would care to share? I would love to know what to expect for the price we are paying for the tubes.