Amplifier Pairing with Coherent 15s

Hello all,

About to finalize an order for a pair of Coherent 15s (yay!) and now I'm starting to look at possibilities for amplification for them. Since they are very efficient (I believe 106db efficiency), they can work well with flea amps+, so there's a wide range of possibilities.

I have a few criteria though: I would prefer an integrated amplifier vs separates/mono blocks, both for cost and space reasons, so something like AirTight is out (plus, a bit too expensive anyway). Looking around the $10k range at the higher end.

I don't listen to things super loud, and tend to prefer tube amplification. Music tends to lean majority Jazz, with some other things throw in here and there, but Jazz is the most important genre to get right.

Frank (from Coherent) recommended a couple -

Tektron Two 2A3/50S-i
Mastersound Compact 300B

Some others I've looked into:

Tektron Two 211-i
LTA ZOTL Ultralinear Integrated

I do have a few concerns with hand-crafted, more 'custom' made amps, especially by manufacturers overseas (I'm in the US) - mainly inability to demo them and ease of service/warranty. They also tend to be more difficult to sell in the case of deciding to go a different route, though this is of a lesser concern.

Anyone have any experience with any of these, have any other suggestions to explore, or any other comments?



From what I've seen, The o/96 is 10ohm and 96db (though, seems like they test closer to 91db, at least from Stereophile review), so they aren't as efficient as they're made out to be. I looked at the O/96 as an option around the same price point, but I just am not a fan of that type of speaker - they are similar to Audio Note and both are 'inspired' by Snell. I feel like they might need a push-pull or parallel 300b to really sing, but I know there are folks out there using SET with the O/96 and are happy. Diff'rent strokes!

I believe the room with the Coherent 18 was 'best of show' in the Montreal show you are referring to, @alexberger?

Hi @mmcgill829 ,

Yes. To my taste this room was the best on this show.

I liked this Coherent Model 18 room sound 2 years ago with the Allnic Audio T-1500 integrated 300B SET. A year ago Model 18 was drived by Allnic Audio monoblocs. It still sounded good, but I liked the more warmish sound with the Allnic Audio T-1500.


I double checked.

On Montreal show last year Allnic Audio M-2500 monoblock power amplifiers derived Coherent model18 speakers.

Yeah, I believe the dealer Frank shares a room with deals with Allnic so they get paired together a lot. The M-2500 is a bit overkill for these speakers, I think.

But really, if you are in the market for over 100db efficient speakers, it's usually because you want to run low-power SET. 😅

There are many great amps that will drive your Coherent speakers well. I had a pair of Coherent 8s for years and finally settled on an EL-34 amp and 4P1L preamp by Raul Tarta. Made in CT (as I recall). I know, you prefer an integrated solution but these are great, unsung products and a great value. Made in the USA. Simple Pleasure Tube Amps

I'm surprised that no one has mentioned Decware. Steve Deckert is a legend in the (mostly off Audiogon) audio community and he offers several integrated amps, of different configurations. FYI I believe that all of the Decware amps use a passive preamp section. But they are very well made, sound great and seem to retain phenomenal resale value.