[Musica Amantem]

I believe, based on my own experience with the KT-88 Triode-strapped Inspire amp (20 watt trannies and long chassis), that the Gold Lion KT-77 works wonders because it is a distant relative of the EL34 Pentode, the only tube which can be strapped in Triode mode naturally, given its internal configuration. A quote from Steve Deckert (Decware):

"... [I]In a pentode such as the EL34 where the screens are not tied together internally, it is possible to wire it as a "true triode". It is the only pentode I know of that is. The other ones have internal connections on the screens that can't be changed so you end up with a ´Pseudo triode´"

Although one would think using EL34 would theoretically beat the KT-77, hands-on experience from others have testified to the contrary, making that special combination of KT-77 (a "hybrid" between the EL34 and the KT-88) the best approach short of a real Triode. The cited KT-88 is really an excellent tube in the Inspire, on its own merits (again, referring to the Triode-strapped mode), so best-of-both-worlds, as they say.

Mind you, I have NEVER heard a 45, 300B or 2A3, so I cannot judge the midrange quality in my amp relative to those others, but at least I get to use different tubes and cheaper replacements with an outstanding midrange and highs, along with some higher SPLs. With a sub crossed anywhere between 50 and 100 Hz (in my case), these also have outstanding bass. Just my $0.02, YMMV.

Other than keep improving the source side on my gear, a technologically ever-evolving field, the best upgrade after the Inspire Lp-27a and HO amp is definitely a finer set of loudspeakers, which would ultimately do justice to that amplification and sourcing setup gem.