I have the PrimaLuna Evo 400, and Had the Ayon Triton 3 Gen 4. Both great amps. So lets narrow it down:
Sound: Both sound great. How much power do you need? Spirit, Evo 400 same power, more or less.
LOOKS: Very subjective. As far as exterior finish, it's like the difference between glossy or satin paint. Exterior wise, I personally Lien toward the Ayon Spirit. Interior wise, based on the picture I see here of the Spirit's internals, and the picture of the Evo 400 internals on PrimaLuna's website, winner, PrimaLuna. The Spirit's internals look sloppy compared to the well laid out Evo 400.
TECHNOLOGY: Both very advanced tube amps, but the PrimaLuna by far has the best autobias system. Tube protection done by relays, no fuses need to be replaced if tube craps out. Just turn amp off, remove tube, put new tube in and turn the amp back on. Don't even need to match the tube. Don't know about the Spirit, but biasing the Triton 3 Gen 4 required a few more steps, but it had pretty sophisticated protection circuitry.
Flip of switch for low bias: 6L6, 6L6gc, El34, KT66, KT77; high bias: KT88s, KT90s, KT120s, KT150s ready for use in the PrimaLuna. Spirit, KT88s, KT 90s, KT120s, KT150s. Pretty much that's it.
As far as other advanced features, they both have a plethora of them. You can pretty much check that out on their respective website, of which, PrimaLuna's get the nod there.
Some other notes about technology: Balanced Audio Technology (BAT) pretty much now uses protection circuitry like the PrimaLuna's on their current REX tube amps which sell for new somewhere in the area of $30,000.00. BAT was one of the frist amps companies to use auto biasing, but until at least the 56se, 60se, 75se, they used fuses which had to be replaced if one blew because a tube went bad; Audio Research's VT80, 80se, which I think is the only Audio Research tube amp (I could be wrong here) that has auto biasing, still uses fuses for tube protection. If a fuse blows it must be manually replaced.
So bottom line: If someone reading this is looking for one of the two amps talked about in this thread, my recommendation: If external looks is your most important criteria, for me it would be the Ayon. In most other regards, though, it would be the PrimaLuna. Never-the-less, I don't think you could go wrong with either of these amps. More money might get you more power, but it won't get you better musical sound. And how much power do you need? It really can be a fool's errand sometimes.
Old timer who was partners in a highend, preowned audio store for many years, and pretty much has heard hundreds of amps, speakers, tuners, you name it audio, that was current up until about 2007; now buy and selling for my own pleasure.
