Look for a used Dennis Had Inspire KT88 Firebottle on audiomart sites. He hasn’t built many, but for $2k you get the performance of a $10k SET amp. He built me one last summer, it blows away my Willsenton R800i and Oldchen EL34 for texture, tone and layers of holographic imagery.
Inspire:
Hey, FYI - as a former owner of Dennis’ Cary and Inspire amps both, I would NOT strongly recommend the Inspire SET or SEP amps to someone with 90db speakers unless they were at least 8ohm nominal impedance, and only wanted to listen at lower volume levels. I ran my custom 93db speakers with Dennis’ Inspire Hot Rod KT150 amp, 10wpc and it was simply NOT enough drive for even low volume level listening. I moved to Quicksilver Mono amps and it was like somebody turned the light on the room by simply having bigger transformers and a bit more power.
Speaker matching is critical with the little mighty Inspire amps, imo.
Great amps with Inspire, yes, but I’d be running 96-100db or more speakers with the little Inspire amps. Some of the higher impedance Proac speakers, 8ohm+ do okay, but you still have to crank it up a bit much.
My audio buddy (SETDude) in FL has two Inspire amps (SEP KT88, SET 45) amps in rotation right now - he’s replacing both with a Cary SLI-80 integrated amplifier which runs 30wpc Triode into his Klipsch Hersey IVs at 96db. Told me this week it is more effortless drive than his little Inspire amps have. Worth noting for someone who is looking for an Integrated amp for 90db sensitivity speakers like the OP with Triangle speakers. Maybe some better options out there for the OP imo. Opinions vary.
Black Ice Audio:
Jumping on the bandwagon, I would also like to put in a good word after helping two friends who had 89/90db 4 & 6ohm speakers and wanted an integrated. While the parts are made overseas and final build in the USA is the case, the folks at BIA are to be commended for their service and support. It’s as close to dealing with the MFG as you can get, in the USA. If you are good with the looks of their amps, you’ll be hard pressed to find a better value for the price and sound - and if you want USA direct service. A few friends have tube rolled new production tubes in their amps too and done well. I’ve been helping friends since old Jolida days, and the new Black Ice Audio amps are another great option to consider, nice integrated amps for the $.
