300B Advice

High grade 300B tubes will provide far more of what you're looking for than the lower cost variety. Full potential of good 300B amp will never be explored with these lesser tubes. Add Elrog, Psvane Acme, Linlai Elite, Takatsuki to your list of superior tubes, all are fine tubes.

However, some are lush and warm whole others are open and transparent. 

*while

Before you spend a lot of money on the higher priced 300B options I suggest you read everything you can find about the various options. There are so many kinds of 300B tubes for sale at the present that it can be bewildering.

The JJ tubes don't get much respect. But they are excellent tubes. Respect seems to be strongly correlated to price and relative rarity. 

Here is my perspective, which I hope makes some kind of sense. Performance is associated with frequency response. Differences in performance are characterized in different ways. A tube with a comparatively upwardly tilted frequency response will be characterized as "more open" or transparent. A tube with a comparatively lower frequency response might be characterized as having a beautiful midrange in which vocals sound amazing. Similar comparisons apply with respect to upper bass and lower bass. I'm NOT arguing that one is better than another or that one tube is superior to others. 

I'm sure that the various brands and vintages of tubes sound different. It does seem that those who spend $$$ on the higher priced tubes become cheerleaders for their favorite brand. It makes sense.

But I don't personally know anyone who has purchased and been able to compare the multiple vintages of Western Electric branded tubes. IMHO the current production WE tubes should be considered reproductions, just like those manufactured in China and around the world. I'm not saying they're not great tubes. Those who buy them seem to love them. But I've not read an in-depth analysis comparing WE engraved base tubes to later production and current production WE tubes. Nor have I read an in-depth comparison to Takatsukis, all the variants of TJ Full Musics ("mesh plate", graphite, etc.), EMLs, various LinLais, various Shuguangs, Vaic, etc. All the comparisons I've been able to find exist at a certain point in time, based on the tubes available to the reviewer at that time. These reviews can help point the way. But I haven't read any reviews comparing all the current production tubes. There are way too many!

Also, performance must be considered in the context of a system, circuit and equipment. What choices did the designer make in voicing the amplifier? How did he choose to drive the 300B? 6SL7? 6SN7? 12AU7? What transformers did he choose? How efficient are a listener's speakers? What load do they present to the amplifier? What is the room like? Carpeted? Hardwood? Wall-to-wall? How many bookcases in the room? How many reflective surfaces?

IMHO, none of the 300Bs sound "bad". It is a wonderful tube and current production tube manufacturers seem to have solved the reliability problems. They all seem to last quite well, though in your research I expect you'll run across failures in and out of warranty. Those seem to be the exception these days.

Enjoy your amplifier and the music!

300B amps tend to be very sensitive to the 300B tubes in them. I was quite shocked at the improvement I got when I replaced my stock tubes with Takatsuki. Wow, what a difference in warmth, musicality and details. But then for the $1K each  they should. I did extensive research and concluded these were the best for my tastes and have often enough tried to buy something for 1/3rd the price, then 2/3rds the price… and finally the best and wasting more money than had I just bought what I determined were the best in the first place.

I have been really well rewarded for this purchase every time turn it on and listen.

markusthenaimnut---very good comments!!!!

For anyone who has the time, click on the link below.  A classic 300B Shootout.  IMO, they are all very good tubes.

Direct comparisons are difficult to come by, and seems most reviewers enjoy the tubes they purchased. This could mean all are pretty nice, been my assumption. After much research over at least a year, I found it pretty much a crapshoot on which of the nicer 300B to purchase. EML and WE are the only boutique 300B's I've not seen a single failure of, but may not be voiced for everyone. I've seen failures on every single one of the others, tube construction may not always be responsible, some of these amp manufacturers run higher plate voltages than some of these tubes can endure over the long term. So, due diligence is required here, both on voicing front and reliability.

@willgolf Thanks for that link. That's the evening sorted. 

@ghdprentice You're right. The Takatsuki is splendid. The warmth and lushness you ascribed to it is there but not in a mushy way at all. It's the long sustain being captured that fills the room.

What you are missing could  very well be a pair of speakers that produce a beautiful, lush midrange when fed by wonderful 300B amplifier.