Neutral and open sounding 300B tubes

If you have output transformers in an amp, you cannot choose a 'better' 300B because you'll  have sound artifacts, so the differences will be muted/distorted.  If you have a resistor based volume control, you cannot choose a better 300B, because again the differences will be muted. If you have an OTL amp AND  a Transformer or LED volume control, you can then give us all an accurate description of the sound a 300B.

Well, my experience is quite different I must say. My Coincident Frankenstein MK II mono block 300b SET has output transformers. Over the years I have had the opportunity to use a wide variety of 300b tubes.

Elrog
EML XLS
EML Mesh plate (a legitimate "mesh plate")
KR XLS
Takatsuki
Shuguang black Treasure
Western Electric Reissue (1990s)
Electric Harmonic
Sophia Royal Princess
Sophia Mesh plate (actually a perforated plate, not a true mesh).

With my system I could very easily and pretty quickly discern and hear distinctions (subtle and not so subtle) amongst all of this tubes. Each one of them clearly has their own unique sonic character.
BTW my system utilizes the Coincident Statement Line Stage which has transformer volume controls. What 300b OTL amplifiers are available?
Charles

Have you thought about KRs?  One of the things that is interesting about the KRs is that they offer a higher plated dissipation than a typical 300B, 50w vs. 40w.  Wonderful all around tube that will bias a little higher without compromising tube life.    

It is a bit slow in getting them because of COVID 19 but these are on your budget ($1000).  They deliver more than the EMLs.  

The other interesting tube is the the Sophia Classic in Blue Glass.  They are best with Sophia's rectifiers.  

Be cautious of the EML mesh plate.  You need to potentially lower the bias as it operates best at 22w and will burn up above 28w.  This is not a problem on other 300Bs.

We sell a lot of 300Bs and I have EML, Sophia's current stock (which is abridged) and KR.  Site is www.artaudio.us  

Two variables that must be taken into account are
The individual listener’s specific hearing and taste.
The specific 300b amplifier design/circuit.
Some brands of tubes just match better with certain amplifiers and less so with other amplifiers. Not really surprising this would be the case.

I had the KR XLS and the EML XLS at the same time. IMO both are exceptionally good sounding upper tier tubes. Directly compared in my system I preferred the EML by a modest margin. I could easily understand someone else preferring the KR XLS. Both are excellent 300b choices. So were the Takatsuki and Elrog in my Coincident Frankenstein 300b mono blocks.

This is why I find it difficult to make universal recommendations. The above mentioned variables (and others) come into play. Someone could say that the Psvane ACME (Or their W.E. Replica 300b) tops them all in their system. Bottom line, there are very good choices available amongst upper tier 300b tubes.
Charles