Favorite 300B: Sophia vs KR



Which do you prefer; S.E.T. Princess 300B Carbon Plate or KR 300B WE Clone?

I've only experienced NOS 40's/50's WE so my expectations are pretty high. Which do you think captures the essence of the WE most closely? I'm trying to keep the cost down as much as possible so EAT is not an option, as much as I was blown away by their KT88. I considered current WE but they're not in production until Spring 2011.

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sakahara
David, I have had one experience with Dave and Sue regarding their RP 300B and they had provided me with top quality service. Your thoughtful post shows of your own integrity.
Great post Watersidedave. It's going to help a lot of 300b lovers understand tube selection a bit better. I’m also happy that ultimately, you found Sue and Richard as accommodating as I have.
Dave, thanks for your excellent and very informative post. One small correction, though. I think that when you referred a few times to "grid voltage" you probably meant to refer to "plate voltage."

Regards,
-- Al
It's been months since I last responded to this thread, in truth I had forgotten about it. So it is long past time to do so. In my previous post I wrote about having a few problems with some of our Sophia tubes.

At the time I was trying to find out if anyone else was experiencing the same problems - so I could possibly find out why.

The grid voltage in our amplifiers at the time was set at 425 volts. Though this is well within the old standard Western Electric specifications which suggest a maximum operating voltage of 450 VDC - in the end we found that it may not be an optimum design voltage.

Since my early June posting, we have found that operating at such high voltages all the time is not necessarily the absolute best design point for an amplifier to have - especially considering the fact that an owner may indeed roll any number of 300B tubes through a product in its lifetime. And as all of us 300B lovers know, sometimes some sets of these tubes can equal the price of a nice house payment.

So extreme care and safety is always going to be a good choice.

Some current production tubes such as the EH Golden Lion for instance, may indeed give a much better experience when operated at a higher voltage. As a matter of fact, in one early prototype set of monoblocks we actually boosted the operating voltage to well over 500 volts with a set of Golden Lions in place and got the best sound we ever experienced from these particular tubes.

Still to this day eight years later that quad of 300B tubes are operating strong under this condition. But of course there is no way that we would ever consider using that high of a voltage in a production unit.

I will say though, that the sound quality from that early pair of prototype monos never surpassed anything that we installed Sophia products into.

It seems that possibly some of the newer tubes available today, especially those from the higher quality manufacturers like Sophia Electric just seem to like a lower operating voltage. And it will certainly give you a much longer tube life as well.

I called Richard of Sophia several times last June, and he helped us by suggesting that we lower the grid voltage in our 300B amps to between 350 and 400 volts. In doing so we have seen the merit of his vast experience working for years with a new line of vacuum tubes that does not stop with only the 300B.

So take this tidbit of knowledge for what it is, just a suggestion. In our latest round of experience, and with the help of Richard of Sophia Electric, who certainly knows more about 300B and other vacuum tubes than I ever will.

It may be a good idea to become well acquainted with the specifications of any amplifiers that you are considering in the future, especially the operating voltages of the power tubes. The lower the voltage the longer these sometimes very expensive tubes may last. And we now know that the with the proper design throughout, the sound does not suffer in the least.

All of our 300B amplifiers operate now with a grid voltage maximum of 380 to 385 VDC. We have not had a single bad experience since making this change. And though we install a myriad of different current production 300B tubes - according to what our customers' personal taste - the best by far, in my opinion at least, is the line from Sophia Electric.

Knowing that Richard and Sue stand behind their product line and take immediate action should anything ever go wrong is another huge plus for that brand.

Knowing that at any time I can call an experienced engineer like Richard when we are developing a new product also comes in handy. I might add here that since Sophia Electric also manufactures 300B amplifiers - he is actually if a direct competitor of ours!

I wish everyone in the high end electronics industry had such a high level of integrity! But alas.....
Hi Ian,
Good question,
Takatsuki=95
AVVT 32SL and EML XLS = 90
Shuguang BT=80 still a solidly good tube but for me not to the level of the current production EML XLS.
Sophia RP, been quite awhile but it was very good in the Frankenstein(I`d need to hear it again). This tube has a different character compared to the two european 300b tubes.The RP could be a "touch" better but a very close call. I honestly feel there`d be an amp to amp variation,favoring one over the other.
Charles,
Charles,

I was wondering given your considerable experiance since posting this:

On a very strict scale where 70=solid performance and 100= absolute perfection.In my system I grade the following,
W.E.reissue =70(just did`nt impress vs the others in my amplifier)
BT=85(very good all around)
RP=93(excellent!)
Takatsuki=95 (sublime experience for me)

How would you rate them now adding in tubes you've compared since, (lsuch as the AVVT etc.) like you to use in the Franks.

Ian
I second all of Onemug's comments.

The 5 hour recommendation has to be somewhat arbitary, even for the specific Sophia tube, because to the extent that an optimal figure may be definable for any specific tube, the figure will vary depending on its operating conditions in the particular amplifier.

FWIW my own instinct, based purely on instinct, would be to not hesitate to have listening sessions now and then that are significantly longer than that, but on the other hand to not run any tube power amplifier continuously 24/7, or overnight, or when unattended. The concerns being not only the likelihood of shortened lifespan of expensive tubes, but the possibility of secondary amplifier or speaker damage, or even fire, if a short or other fault were to develop.

Best regards,
-- Al
Thanks Onemug, The lack of any response in support of the notion that tubes need to rest hasn’t been lost on me. There are a lot of smart people on Audiogon. I could have taken it wrong, but in the context of our converstation, I came away with the strong impression that I was being advised to give the tubes a rest to avoid overstressing them. Not because they might pop, but because there would be an accumulated effect that could adversely impact longevity.
Onemug,
Good points, I wouldn't advise anyone to use their output tubes 24/7.I do have my amps on 8-12 hours on some days and have had no problems. The 300b is long lasting if not pushed hard by circuit design as you noted.
Regards,
Phaelon,

Couple of my thoughts on tubes and specifically 300b's (one of my faves):

I haven't heard of any manufacturers of tubes recommending limited hours but I wouldn't be surprised if they did. 24/7 is around 750 hrs a month or 9000 a year. That's a lot of hours on output tubes. I can imagine a scenario where there are 2 people with identical amps and running the same tubes...the 24/7 guy gets 6 to 9 months on his, the "on often" guy gets years on his.

Another factor is how hard the tube "amp" manufacturer chose to run the tubes in his design. Good to know specs are the voltage and current. I've seen charts on 300b tubes that have said you can run up to 450 volts and up to 80 milliamps BUT NOT BOTH.

Get an amp that runs the tubes near the ragged edge and they won't last as long as compared to an amp running them more conservative.
@Watersidedave

Have you talked to Sophia and what's their comment?

It looks like mega failure regarding quality control, can't be any differ.

THX
Just to be clear. I received no formal, written restrictions from Sophia. It was during a casual conversation with Sue that I received the five hour advise. Most of my friends, who have tube amplifiers, also try to minimize very extended sessions. I thought that this was common understanding. If this is unusual, I would welcome the thoughts of some of our more technically advanced members.
Gary,
I don`t believe this is universally true for the 300b.I have EML,AVVT,Shuguang BT and Takatsuki and none of these came with this type of warning/limitation of playing time.
I`ve used them with the amplifier on morning to night without any problems. Sophia Electric may have their own chosen restrictions.
Charles,
"And when the 300Bs are in service I will leave them on constant without powering off for a month or more straight at a time.”

Isochronism, Just a heads-up: In order to maximize their longevity, Sofia recommends that these tubes should not be left on for more that five hours at a time.
I will also report that I have been using my Royal Princess pair on and off (I switch with 45 amps) for over six months without a problem. And when the 300Bs are in service I will leave them on constant without powering off for a month or more straight at a time. No problems at all.
I also have received only very good service from Sophia company.
Watersidedave, I’m sorry that you’re going through this. What are Sue and Richard doing for your customers? FWIW, I will conservatively estimate that I have at least 2000 hours on my quad, without a hiccup.
I used the Sophia Electric RP 300b for several months before getting the Takatsukis. I did not have any issues, but I did not use them hard or very long.
Lately I have had quite a bit of experience with the Sophia Princess, Royal Princess and Sophia Mesh Plate, but only versus the EH Golden Lion 300B and the JJ 300B, both of which are pretty mid-level performance and sound wise.

The Sophia Electric tubes get consistently better as you go up the chain from the Mesh Plate and ending up at the Royal Princess. I was so impressed with the sound that we started recommending them to our high end customers.

Well this has started to become a real problem. Out of every single quad purchased, at least one has eventually failed. Up to a total of four failures now. And today I received an email from my best customer and he has experienced another burn-out. Disturbing to say the least.

When I started looking I am now finding several other manufacturers and private individuals that are experiencing the same thing as me. But still less than a dozen instances. The main thing being that a few weeks ago I could only find a couple of internet hits on the Sophia failures.

Is anyone else out there experiencing this situation?

We have actually had this occur in three different amplifier models with slightly different topography. We even upgraded a few of our mono blocks and stereo amps to try to make them more robust against possible burnouts by installing larger resistors on the power grid end etc.

Still, the new email came in.... same thing again.

So far all of the tubes have had shorts inside that caused visible sparks and pops, whereafter we find failed tube socket resistors of course.

Anyone else seeing anything like this?

The EH, JJ and WE are all still going strong without a single instance of failure. Even in some of the same amplifiers. Flawless against several failures. Seems hard to overlook.

What a shame because the quality of sound coming from this particular brand of vacuum tube is pretty darn fantastic. I absolutely love the incredible lifelike sound we were getting, so it is a real sad thing. At least it's good to hear about the Takatsuki TA-300B. Maybe my customers will give us a second chance now!
Hi max,
I've been using the AVVT SL 32b very regularly and must say it is a superb sounding tube in my amplifier. I will return to the Takasuki and then post my impressions.There won't be a loser IMO just different attributes they offer.
Regards,
Hi Charles1dad

Yes, still use them, they are one of the best out there, build like a tank and if you have the correct production year, something like after 1999?, they must be problem free, however, they still tubes after all and can stop working just like that anyway and this is the biggest problem, if you compare to present production, you can't get replacement pair, unless you bought from dealer and they are dead within the warranty term, but like I said, they are running out soon, so, dead is dead:-(

I own KR Tubular type as well, which are AVVT made, but KR branded, and I am bit spare on 32B's as they will be harder to get pretty soon.

I think Takatsuki will be more delicate / bloomy vs 32B's, which are linear.

Regarding amp been used. I am convinced that in some amps tubes do not make that huge difference as in my Cary for example. The one I am talking about is Zanden 7000, which no longer made, but Royal Sophia's were great there, while in my Cary they were so so, if not less. Actually, AVVT's and KR's I own sound best in my Cary and if I had the free cash, I would buy another pair of 32B's

Let us know about AVVT vs Takatsuki's please.

THX
Maxmad,
I realized that this thread has been inactive for a while, but oh well.Are you still using AVVT in your Cary amp? I've been using the AVVT 32b SL for the last several weeks and honestly, this is a wonderful 300b. We have different amplifiers so just interested in your impressions. One of my Takatsukis failed (extremely rare per the company with 1, 000 pairs sold so far).Amtrans has been responsive and is sending a replacement pair under their warranty.

I really look forward to comparing the Takatsuki with the AVVT 32b SL.Physically these two 300b look nothing alike and very likely use different construction and materials. Yet both are clearly successful sonically.
According to Jac (Jac Music Germany) this model AVVT has a 40, 000 hour lifespan!
Amtrans said they were not permitted to export to the US after the end of 2012. They would be happy to sell the tubes in Japan but could not ship to the US.
Did Amtrans give an explanation?

The US importer is

Axiss Audio
17800 South Main Street, Suite 109
Gardena, CA 90248
Tel. (310) 329-0187
Has anyone found a source for the Takatsuki TA-300b ? Amtrans can no longer export them to the US.
This thread become sleepy, so , I thought, maby there are some news/impressions out there...

THX
I reread the thread, interesting , probably tatasuki but the SRP seems to be not much behind
I am currently using the sophia electric royal princess.
I have not heard another ,are they the best or is emission labs better for example ???
i do like the sound , very transparent and good overal dynamics / bass
Charles1dad,

I honestly have been so taken with the Takatsuki/Frank pairing that I have not yet followed through on the Vac 30/30 pairing as of yet. The second set of Black Treasure tubes I purchased here on audiogon, purportedly from Grant Fidelity, are shorter and don't have the box markings that the ones I purchased with the Franks have so I'm a little afraid to pop them in without testing first. Unfortunately my tester doesn't do 300B's. I will find an avenue to get them tested before I try them out.
I'm currently breaking in the ASI livelines between amps and pre and the sound is just now starting to come around a little at 70 hours. Wasn't really impressed right out of the box but have the feeling they will be stellar after a few more hours
I'll keep you guys posted on the VAC/Black treasure pairing.
Markus
Hi Markus,
Have you formed an impression with the VAC REN 30/30 and your Back Treasure tubes?
No problem Jason. It was great speaking with you and look forward to meeting you in a few weeks.
Thanks Tony (Clio09) for the call today, look forward to seeing you at THE Show in Newport Beach, CA and hearing your gear in person.
24H365,
Just for a scale of 'relative' comparison the differences between the two linestages were noticeable but not at all night and day. The insertion of the Takatsuki tubes were by comparison profound. The Frrankenstein-Takasuki is simply 'it' for me at this time, just captivating involement.
Hi 24h365,
I compared the TRL Dude and the Coincident Statement Linestage on my system page in mid-december 2011.The Dude lived up to the hype and praise it has gotten.For its price it`s hard to go wrong. Ultimately I found the Coincident better yet, it was more open,transparent,refined and nuanced etc. Both are exceptionally dynamic,large in scale and authoritative.The Coincident simply disappears more(lower noise floor) and has no perceptible veil at all (just lacks any signature IMO). YMMV.
Regards,
Clio09, I just went to the website and filled out the contract us page. I'd be interested in hearing how your amp designs compare to the Shindo line of tube amps.
OffTopic: Charles1dad - So what was your impression of the TRL Dude with your Franks? Could you elaborate some. I'm in the market for a pre and have the Sophia Electric 300B mono's. Thank you
Charles, the output tubes are biased on the high end, so yes, tube life is likely to suffer somewhat. On the other hand the sonics are improved. Such is the trade off.

Perhaps we can work out a demo for you. If you go to the Electra Fidelity website, complete the contact us form, and send it off I will respond with my phone number so we can chat. We would like as many people as possible to hear this unit. Shows are obviously a good method, but in ones own system is always better. Auntjenof2 just happens to be in the same town which made things easier for him.
Clio09,
Thanks for the explanation. Low noise floor is one of the strengths of the Frankenstein. Just for fun I `d like to hear the Franks/Takatsuki (rather than with the Psvane Treasure 300b) compared to your new amp. I say this knowing the vast superiority the Takatsuki provided when I switched tubes(bass,clarity,seperation etc. as these were the same improvements cited by Auntjenof2 with the new amp). Your amplifier sounds like it could be a really great product. Does the increase voltage and power rating affect tube longevity? Thanks again Clio09.The more choices in high quality low power amps available the better IMO.
Charles, bear in mind that I'm not the technical brains of the operation nor will we be able to disclose everything about this design since some of it will be kept proprietary until patents are issued. I would not say that the design is necessarily unique from traditional Class A, but it is different in that while the product of the plate power on the output tubes might be the same in both classes (ex. 300B tube), the voltage in an A3 circuit is higher and the current is lower. Since the power is developed by more voltage the result is more lifelike dynamics. This holds true only if the tube can take the increased voltage in A3. Not all can. We could not do this with a 45 or 2A3, but the 300B and EL-34 were rugged enough to take on the increased voltage. Today in an effort to determine if more power could be generated, my partner Jack burned through a number of EL-84's and 7189's that failed the test. We will most likely just stick with the 300B and EL-34 and be satisfied with the 10 -12 watts of power.

What has also been accomplished using this Class A3 circuit is a drop in THD and more importantly IMD. Measurements indicate a lower noise floor as well. This was one of the first things we noticed when swapping out the Coincident amps for our amp in Auntjenof2's.
The posts on Jack Elliano intrigued me enough to look at his website where I came across his thoughts on tube rolling (link below). Although it relates specifically to his amplifier, I think it underscores the advise given by Charles1dad and others - that it’s not enough to buy a great tube - the tube only achieves greatness when implemented synergistically.

http://www.electrafidelity.com/tube-rolling/
Just to clarify a few things regarding the Electra-Fidelity amp referenced by Auntjenof2. The amp is a proprietary (patent pending) Class A3 design by Jack Elliano of Electra-Print. In developing this Class A3 design we enlisted the assistance of Ralph Karsten in reviewing Jack's research, however, he was not involved in the circuit design process. Ralph was very supportive of Jack's effort and the result is that we now have two amplifiers in production that will operate in Class A3. The A3-500 is a 300B SET amp with a circuit designed by Jack Elliano that puts out roughly 10 watts. We are sending an amp to Ralph on loan for use in a new project he has started. The yet unnamed EL-34 amp puts out roughly 12 watts. The circuit for this amp dates back 20 years or so and was originally developed by Cy Brennamen with assistance from Jack Elliano and voiced by Bruce Edgar for use with his horn speakers. Jack recently updated the circuit for Class A3 operation and has achieved substantial improvement as a result.

The 300B version was at THE SHOW Las Vegas this past January shown with Fritz Speakers Carbon 7's. The amp easily drove the 87 dB speakers which astounded quite a few people since on paper this appeared to be a huge mismatch. We will show the 300b and EL-34 in Newport this June. Our room will feature Fritz Speakers, WyWires, and Resolution Audio products as well. If you are attending the show feel free to stop by for a listen.
Sorry, one more comment. I was told the 300b version of the Electra Fidelity
amp will be at T.H.E. Show in Newport beach in the room with Fritz speakers,
Resolution audio Cantata, and Wywires. You can contact Anthony Chipelo
(Clio09 on Gon) of Electra Fidelity for more info. Or if you are near Vegas
and want to hear my el 34 version shoot me a message.

George