I've not posted on this thread before - part of me wonders what I might be able to add given the volume of information that is here (I skim read all 155 pages last night during a wonderfully monster listening session until the very wee hours of the morning, knowing that today is day off!)
HeiHei, who I know personally, loaned me his KR242s to try in my VC GG1. I'd only listened to them for an hour or so before I concluded I really didn't like how 'shouty' they were (too forward, too bright, too harsh) and at times they were simply distorting at the higher end of the frequency range. HeiHei suggested I turn down the volume on Roon to prevent the pre-amp - a Concert Fidelity CF 080 LSX - from becoming over saturated. This works well but turning the volume down on the DAC itself works better.
Once I did this the whole thing snapped into focus; the results were quite special and orders of magnitude different to my thus far preferred 300Bs.
On that point, I have always run my GG with 300Bs and a RK 5u4G rectifier. I started out with cheap Chinese tubes that came with the (reconditioned) DAC, but then moved to PSVANE Acme 300Bs, which I liked very much. I then tried the reissue WE300B (also courtesy of HeiHei) and liked those even more, but the cost to buy was twice what i paid for the PSVANE and I didn't really see the value.
But then Greg at G-Point offered me a set of well used (50% measured life left) original Western Electric 300Bs for a very good price, so I part exchanged my PSVANEs for those and have been enjoying their magic for six months. In the end, after PXing the PSVANEs they cost me ~EUR1200
It's churlish to talk about which are better, the WE300Bs or the KR242s, that would be like arguing over whether a Hasseblad 503 is a better camera than a Mamiya RB67; they aren't even the same aspect ratio for a start!
The differences are stylistic and personal preference will dictate which you enjoy more; the WE300Bs offer much more openness, spaciousness and transparency. The soundstage is larger with more depth and 3D imaging. The sound is fluid and effortless and very easy to listen to for long periods without any fatigue. These original tubes sound better than the reissues but they are very like the reissues (or rather the reissues are like the originals).
The KR242s are fast, focused and full of energy. They drive the music along with tempo, pace and verve, injecting a considerably amount of what I like to call 'hurry up', a phrase that occurred to me when listening to a pair of 2watt Thomas Mayer 211 power amps driving a pair of Pnoe speakers; the music sounded diaphanously, pellucidly transparent, gossamer thin and gorgeous but ultimately I was left feeling impatient, like trying to coax a small child into putting on their shoes – ‘would you just get a bloody hurry up on!’
I love the energy of the 242s; love the emphasis and edginess they give to the music, something that a 300B could never hope to achieve. In the context of my system, which comprises Silvercore 833 MKII SET amps and Horns FP10s down the chain, that energy and drive is very welcomed, but if I had to only have one pair, it would be the WE300Bs, my originals, not the reissues. Fortunately this is not an either or situation, but rather a ‘yes and’ one. Interestingly, I also find that I don’t switch depending on the music I am listening to, but rather the mood I am in. All styles of music benefit from the qualities of these two vastly divergent tubes, and it’s rather the mood of listener that determines preference on any given evening. Vive la difference etc.