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
Thanks to all for the advice.

I settled on the Karans based upon several people who have actually heard them with the Isis. Roy Gregory from HiFi+ used Karans for his Isis review, and I thought that review was very accurate. I find most reviews to be quite vague in lathering-on the praise, but this one was consistent with my own listening. Roy also has separate reviews of the Karan 1200 and 650s.

For tube amps, I think the choices are basically CAT, BAT, and VTL.

For other SS amps, I think the choices include Boulder 2000 series, Ayre, and Spectral. Gryphon may be good, but no one heard this combination. I think the key with solid state is to have something that is powerful, and with a full mid-range.
Rtn1,
re. the Karan 1200 amp 16A fuses - *if* the amp is 1200W/ch into 8 Ohms (I assumed from the model # that it's 1200W/ch into 8 Ohms. I could be way off the mark!) then it seems that it has a +/- 98V rail. It also seems that it could be drawing 12+ Amps from the wall when providing its full 1200W/ch into 8 Ohms. So, I can see why it needs a 16A fuse.
The other thing is that the power supply caps must be huge in their capacity. So, when the power amp is switched on, there is a huge in-rush current that the fuse needs to withstand. There is probably an in-rush protection ckt but despite that you will need a large value fuse to ensure that it does not blow during switch-on.
However, all this does not tell us whether the amp is class-A or class-AB. All it really tells us is what the amp will draw from the wall -it's a large wattage power amp & it has the potential to draw some serious current!
You can get hint of whether it's traditional class-A or not by seeing if the output power is 1/4 the power consumed from the wall & whether it's sliding class-A or not by seeing if the power consumed goes up with increasing input signal amplitude.
I just heard Isis with the Stratos & Odin

beautifull but a little bit slow for my taste

source was dCS Scarlatti, preamp also Howland
I suspect the amp can make a big difference in how these sound.

The similar Avalons I heard were on a very expensive Boulder amp and sounded quite sweet! I seem to hear this pairing come up often it seems.