I've never seen anybody say a word about the KT77 around here - or anywhere apart from Dave Green when I used to bob into Matamp headquarters whilst he was still there - and his opinion was that it was a great bottle - but no one would wear it... shame is - not many people recognise Dave for his superb engineering - apart from maybe happy Matamp owners, Joel at Electric, my erstwhile bench partner John and myself... but he was right - it's an awesome bottle...
If you own a HRDv and want a bottle - besides a Sovvie 5581 WXT - that'll take the stupid plate voltages that they produce this is a real solution - you just have to carefullly bend the bottom of the tube cage out a bit to fit 'em in - but they pee on Sovvie 5881WXT's...
I've stumbled upon these (despite DG telling me about them about a year ago) because I've been peeved that I've had to 'reign in' the B+ on my Dv conversion (which I hasten to add sounded just fine at 450V plates/Sovvie button base 5881WGC's - just couldn't get any more than 35W RMS/4Ω out of it) because generally speaking - most 6L6's can't take the constant pounding of 500V+ plates at flat out volume (if you bias for 70% with a straight HRDv PT/FWBR it winds up around 504V) - about the only tube that'll take it is the aforementioned 5881WXT - I can tell you for nothing that a perfectly matched pair of Winged C's'll last about 3-4 months in that situation and will just drift further and further apart... the KT77 - OTOH - is built to take all that and more, are less expensive than WC's, and I've just biased 'em for 70% of 30W each and it's like they've said 'yeah - so what's yer point...' and sound really huge effortlessly...
I know we're all tryin' to stay outta tinitis territory - and I really dig my 5E3 clone and it's big brother (thanks again Kap!) but I'm just wonderin' - anybody else ever give 'em a try?