Thanks for the 2A3 descriptions
While you are at it - any comments on various 2a3's?
I ordered my Stellaris last August for this (past) June delivery. I do not want to bother Donald as I am sure he is busy. I also have my recently delivered Stax T2 to play with
Do you mean 5u4g?
Here's some quick impressions from my collection. Mostly I've used these tubes with the Stratus, but I have found that the Stellaris highlights the differences between the tubes even more. I've heard a lot more variants of the 5u4g (various rebranded, sylvania, etc.) but generally didn't care for them enough to include them here. Listed in somewhat increasing order of price.
RCA 5r4gy - has a lower voltage drop than a typical 5u4g so this has softer transients and a much larger, but diffuse stage. Really pleasant for brighter setups, although you lose some precision in imaging and depth.
Sylvania 5931 - compact staging but tone has a richness and overall density that works really well on more diffuse setups.
RCA 5u4g (50s, 60s) - great overall tube that leans warm and is an easy listen. Most suggest starting here because they are under $100 and you can triangulate your preferences from here.
Ken Rad 5u4g - my favorite of the vintage 5u4g, balanced throughout with strong subbass compared to, say the RCA 5u4g. Very clear staging and great tone; a touch bright in the treble for me at times.
RCA VT-244 (1940s double fishing pole rods) - Warm and lush tuning, with strong midbass and a generally pleasing presentation overall
Sophia Electric 274B Aqua - Slightly larger staging than the vintage tubes, slightly rolled off in the treble. Very inoffensive tube and lacks character for my tastes.
Psvane WE 274B replica - Overly refined and almost plastic sounding, but with good dimensionality. String tone has no bite, and ultimately affected the timbre of instruments too much for me.
GEC U52 - Very tasteful presentation, not the largest stage, but very clean images. Euphonic mids, slightly rolled treble.
EML Mesh 5u4g - much larger presentation than all previous tubes, imaging, staging, etc., is in another class. At times, splashy treble and hard-hitting bass, this is a vivid tube that somewhat counteracts the more laid-back nature of the DNA sound.
KR 5u4g - huge presentation that is a little more further back in the stage than the EML mesh and my preferred listening setup with the Utopia for the way it handles the upper mids. There's a nuance and refinement in its overall presentation of sound that is both enveloping and not up-front, if that makes sense. Excellent layering and imaging.
RK KR 5u4g Anniversary edition - my preferred tube before it randomly died. Very similar to the KR non-anniversary edition but with superior imaging and even more soundstage depth. I'd recommend except that like others I've been burned by their poor QC.
Elrog 5u4g - coming soon.