300B replacement

I recently had a Western Electric 300B die on me. If I replaced the one with a new or newer tube, would i hear an imbalance in the two channels?

Other options i am considering are the Sophia mesh plates, Sophia princess mesh or carbon plates, valve art, or Shuguang nickel plates.

Any opinions will be greatly appreciated.

thank you in advance,


Think it would be better to replace both at the same time as then you would have the same amount of hours on both tubes, instead of just replacing one. If you only replace the one tube, and 1-2 months later, the other one goes bad, then you have to replace that one...the "older" of the two tubes is going to have more hours on it.
Let me try this again...

I think it would be better to replace both tubes instead of just the one as you really dont know how many hours are on the other one ( the good one ).

If you were to replace just one tube , and 1-2 months later, the other tube goes bad, then the " newer " one has more hours on it. That is why when buying tubes, its best to buy them in pairs/quads.
The major drawback of replacing both is the financial side of the equation. The Western Electric 300B is probably about $400 each. I would try replacing one and than listen to hear if there is any imbalance between the channels. If there is then, I would purchase another one. $800 to $1,000 is a lot to pluck down for 2 tubes. Of course, there are other reputable tube manufacturers that produce the 300B for a lot less money. Even if you buy 2 new matched tubes, they might also have different lives and each time you would be wasting at least one good tube, if you always replace them in pairs.
fwiw I have a pair of these and they sound terrific

Use a bias meter.
I'm currently using a pair of the Sophia Princess Carbon Plate 300Bs in my SET amps, and the sound is phenomenal. The Sophia tubes are notably better than the current production model Western Electric 300Bs in my SET system.

Philjolet, have you been able to compare the Princess Carbon Plate 300Bs with your Princess Mesh Plate tubes? I would like to hear that comparison in my own system, but I have not yet sprung for a pair of the Mesh Plate tubes for myself. Maybe some time later this year...
How about sending in the good used tube to a select vendor to test it and perhaps get a better match before buying a second tube.

Sophia are great tubes. Have not listened to the Western.
It's my understanding that the WE 300B may have come with a spec sheet. With that knowledge, WE can at least come close to matching some of the parameters. It may even be feasible to send them your present tube for matching, why not give 'em a call? SET's are one thing, but on my VAC 30/30 push pull, matching is very important for overall performance for the individual channel, noise among other things. Good luck
Cincy_bob writes:
I'm currently using a pair of the Sophia Princess Carbon Plate 300Bs in my SET amps, and the sound is phenomenal. The Sophia tubes are notably better than the current production model Western Electric 300Bs in my SET system.

Thanks for your post.

I ran Full Music meshies (not the Princess) for 5 years (went through two pairs) and replaced them last year with new production WE 300Bs, and I think they sound a bit better than the meshies.

Do the Princess style 300Bs have the same operating requirements to normal 300Bs?

Metralla, I also have a pair of the TJ (Full Music) meshies (i.e., the ones with the globe shaped bottle as opposed to the princess or "ST" shaped bottle). In comparison with the Sophia Carbon Plate and Western Electric 300Bs, the TJ globe meshies sound a bit thin in my system (that is, lacking in weight in the upper bass and lower midrange frequencies.). Both the Western Electric and Sophia Carbon Plate 300Bs are notably better sounding output tubes in my amps.

As for the comparison between the two solid-plate tubes, the Western Electric 300Bs have that magic midrange, but they lose on just about every other account to the Sophia Carbon Plates. The Carbon Plate tubes are significantly more dynamic and much more extended at the frequency extremes than the Western Electric 300Bs. And the Sophia Carbon Plates give up very little ground to the Western Electrics in the midrange department. As a result, my Western Electric 300Bs sit on the shelf collecting dust while the Sophia Carbon Plates get all the air time.

As for the operating requirements of the Sophia Princess 300Bs, the Carbon Plates are a solid-plate design that is 100% interchangeable with standard Western Electric spec. 300Bs.

However, I'm not certain about the Sophia Princess Mesh Plate 300Bs. The Sophia Electric web site seems to indicate they are 100% interchangeable with normal solid-plate 300Bs. However, I recall that the TJ meshies required a reduction in the plate voltage. I think it would be prudent to call Richard at Sophia Electric before running the Princess Mesh Plate 300Bs in an amp designed for a standard Western electric spec. 300B.

How does the above description line up with your listening experience with the Full Music meshies and the Western Electric current production 300Bs in your audio system?
Cincy Bob - I bought my amplifier with the Sophias tubes in it and was not aware there was a carbon plate or mesh plate option. From what I can see my tubes match the photos in the link I posted and documentation that came with them does not specify either.
Cincy Bob I did find the link to the carbon plate and I do have the mesh

sheepish am I...

The SP Carbon beats out the WE and SP Mesh by a long shot in my system.

Can the A/B test with the SP Carbon/Mesh. The Carbon will win out by a lot as I have/had both. One Mesh blew out and I have one with 400 hrs on it. What to do with it?

You have good ears as I second your opinion on the WE and SP Carbon word for word. You took the keyboard right out of my hands. =8^)


I do believe you do not have the Mesh plate but the Globe.

Globe Mesh it is.

Actually (I think) it is the Globe Mesh Plate with ceramic base. Funny I did not notice the shape of the glass but the mesh plate vs Carbon only.

I have something to look forward to: upgrading to the Carbon
Thank you all for your satisfying answers. It looks like I´ll be trying the sp carbon plates. I know I liked the regular Sophia Mesh plates, but it seems that the sp carbon is really a big improvement.
The meshplate tubes are not built to WeCo spec, their maximum plate voltage being below the standard WeCo spec max of 450 volts. A few amps, like the VAC Renaissance amps that feature a Class A circuit and constant high plate voltages (430 volts), cannot use the meshplates.

The claim to fame of the meshplates is delicacy, transparency and finesse, but they have to be used in the right amp.

Thanks for your vote of confidence. And I appreciate you sharing your experience regarding how the Sophia Carbon Plate 300Bs stack up against the Princess Mesh Plates and Western Electrics in your system. You have satisfied my curiosity, and I plan to take your advice and forego my own A/B test with the Princess Mesh Plate 300Bs.

As for the mesh plate tubes and the maximum plate voltage specification, I agree with Raquel's post as it relates to the TJ Full Music meshies. However, I'm not so sure about the Sophia mesh plate 300Bs. The Sophia web site indicates they are manufacturing the mesh plates for both the Globe and Princess tubes with a stronger plate structure. The specifications for both tubes indicate a maximum plate voltage equal to the full 450V WECo spec max. In addition, the web page describing the Princess Mesh Plate indicates "...It is a true 300B tube. It will work with all 300B amplifiers (Western Electric 300B direct replacement)...This is a true 300B tube that is 100% interchangeable with the popular Sophia Electric globe shaped 300B mesh plate tubes and Western Electric 300B tubes, as well as current production Chinese/Russian 300B tubes (with WE 300B standard)."

I guess we need to balance all this against Glory's experience in having blown out one of his Sophia meshies early in its life.

Bottom line is, if you're interested in trying a mesh plate tube in an amp that was designed around WECo spec 300Bs, I think it's worth a call to Richard at Sophia Electric to inquire about the overall compatibility of his mesh plate tubes and whether his tubes have managed to overcome the plate voltage limitations of other popular meshies such as the TJ Full Music 300Bs.