Right then guys...a week of the dual GEC TT21/GU50 power combo per channel, driven by 2x GU50s, has highlighted perfectly the merry-go-round that is rolling tubes from a similar family - and others that perform at a high level, once a certain standard is reached in the rest of one's system...ie. they generally do in fact only bring different 'flavours'/characters and
perceived variations due mainly to the differences in emphasis of certain sections of the frequency range, along with the effects of distortion ('color') - total and intermodulation - depending upon degree.
But
major differences in performance then require other factors to come into play, and which usually mean massive upgrades to some or all of the rest of one's system, and/or another amp entirely lol! However, such a leap has now come from the aforementioned dualled power tube combo...much more so than from just one tube to another, and has me realising that the progression of tubes I have been fortunate enough to discover until now has, in fact, been only
minor in comparison. And this is a realisation that is hitting me harder than I ever imagined...truly a double-edged sword! But reality has a nasty habit of doing this alas
.
And so to repeat, it is now as if I'm listening to a totally different amp, not just one with a few improvements/changes here and there. I shall, therefore, most certainly not be looking to try different tubes any more, simply to achieve further
minor changes...I have finally learned my lesson lol!
Mind you, the journey has at least had the benefit of providing a larger selection of tubes from which to choose according to personal
taste, even if not actually
better!!...which is no bad thing...
.
Finally, although
original tubes undoubtedly give superior performance, I'm quite sure that dualling a reissue KT88 (or one's preferred KT) with a GU50
per power channel will bring similar leaps in performance...and at a fraction of the cost of a high-end amp. And if I remember rightly xulingmrs have in fact already made a dual 6SN7/6AS7G adapter, into which both tubes could of course be put, using their own respective adapters. When they get back on line after their New Year hols I shall check the sockets' spacing to make sure those big boy 88s will fit next to a GU50!!...CHEERS!...CJ