Best Solid State for Avalon Isis


I would appreciate informed comments regarding best solid-state synergy with Avalon Isis. I’m looking for an amp that will maintain absolute control of deep bass, while maintaining a rich and dynamic mid-range, and clarity without sacrificing musicality. It should be transparent, and allow a vast and layered soundstage to appear. Although the Isis appear relatively efficient (90db at 4ohm), the paired 13” woofers are going to need an amp with muscle.

Source is a Wadia 9 series. It runs direct. It does not need a pre-amp.

I listen to big, loud, congested orchestral music (ie. Mahler, Bruckner, Wagner). I like to hear all the detail, including the musician's technique and subtle alterations in tempo. Orchestral sections need to have mass. I want to feel the bass at low in addition to high volumes.

My room is 20 x 30 ft, and has plaster walls/ceiling with wood floors and padded area rugs. Tubes are not an option. Because of the room and source, I am not looking for an amp that is artificially fast or tipped toward the higher frequencies.

A company which is solvent, established, reliable, and with good customer support is important, with preference for an American manufacturer. I plan on trying to home demo some of these, but need advice on where to concentrate and expend my efforts.

These are some I'm considering, and additional suggestions are welcome:
Pass Labs XA200.5
Boulder 1050 Monoblocks
Halcro DM78
Spectral DMA 360
Edge NL Sig One
Hovland Stratos

Thank you,
Rob
rtn1
From europe youi can use:

Symphonic line
FM acoustics
Soulution
Gruensch
Horch

These two last only can be bought in Germany, awesome and with reasonnable price, not very cheap but reasonnable.
Spectral has the reputation for working with Avalon. Jaybo offers good advice.
do the Isis come like the Sentinel with to monoblocks for the bass ?

I have only heard the Sentinel which is working marvelously with Pass electronic; either the big integrated !! (of course because the monoblocks are there) or the XA 200.5 ... extremly beautifull mid-high range, a dream!
Rob
Tubes are not an option. Because of the room and source, I am not looking for an amp that is artificially fast or tipped toward the higher frequencies. I listen to big, loud, congested orchestral music
Likewise. You also want American, so go for Pass 350 upwards (i.e. 600) or the Spectral 360 or 250 stereo or the Boulder Mono. For a more intimate sound & not so loud on Mahler, the Pass 200.5 and the Lamms mentioned above. (The Halcro is great but Australian, afaik.)
In keeping the story short, I strongly advise you to opt for an amp with tremendous output power rather than the quintessential "few golden watts". You can't listen to orchestral music with a few "golden" watts with those speakers.

BTW, the Isis is a serious design, produced by a serious manufacturer. Some other manufacturers are amateurs by comparison.
It also sounds nice. Hold on to it. You may one day purchase (sub)woofers; or you may not.