Atma-Sphere Class D… Amazing

I have a pair of these coming next week for evaluation at my home.

Can we please move the measurement vs perception distraction to another thread so we can focus on Atma-Sphere's new amp here.  FYI, I am picking up a demo pair in a couple hours. 

Just popped the lid as I do on everything according to my wife and since I'm an engineer and do tend to disassemble everything she is right.   

OK I have the Atma-Sphere-D's in my system and have started listening.  "Subjective" report out later but for now some pix and a description of my humble system. The system sounds much more complex in words that it actually is.

Speakers: 1) BD-design horns @ 112dB sensitivity (utilizing the BMS-4592ND coaxial compression drivers w/ custom phase plugs) FYI I have a pair of the new Celestion Axi2050 drivers coming mid-Oct to check out).  Both the BMS and Clelstion have roughly the same frequency response in my horns of ~300Hz-21kHz. 2) The base cabinets are the BD-design Compact Reference w/ 15" drivers running from 38Hz-800Hz.  3)Not shown in the picture is an SVS-16-Ultra for ~15Hz-40Hz.  NOTE: in the pic you will see a sub but that is just part of my JBL soundbar and is only used for TV.

Amplifiers: 1) Coincident Frankenstein Mk-2 300B monoblocks driving the horns (shown sitting in the floor) OR the Atma-Sphere-D's on top of the cabinet where the 300B's normally sit. 2) Crown-XLi-1500 driving the base cabinets utilizing a mini-DSP for xover & volume matching duties. 

Preamp: Don Sachs custom 

Dac: Holo Audio May-KTE

Streamer: Innous Mini-Mk3 + LPS power supply

Cables: Grover Huffman end to end

All... my initial report out of the Atma-Sphere-D compared to my Coincident Frankenstein Mk-2 300B amps. I listened for 11 hours yesterday deep into the night using a pattern of 2 hours between swapping then repeat. One thing to remember is in my system these amps are only driving my mid/high horns so from 300Hz to 21kHz thus I cannot speak to low frequency performance.

I generally listen to blues and classic rock so Etta James, The Commitments, BB King, Marsha Ball, Boney James, Diana Krall, Greg Porter, Eagles, Joe Walsh, Lenny Kravits, Los Lobos, Prince, Stevie Ray Vaughn, Van Morrison, 38 Special, ACDC, Beck, Boston, Chicago, Etc.

The AP-D frankly sounded very good and has a number of strengths as compared to my Frankies. First and foremost, the grip they had on my speakers was immediately apparent with mush improved transients and leading-edge crispness. High frequencies are clean and extended without being sharp and had more energy than my Frankies but the surprise for me was the increased power in the lower midrange to the point where I had to adjust my miniDSP xover for my LF amp to dial down the output curve in the 200Hz to 950Hz range. Of special note is the APD amps are dead quite even with my 112dD efficient horns.

The downside was that the 300B Frankies spanked the APD in the midrange as one would expect since this is the strength of 300Bs with a fuller more textured presentation with bloom and air. While the APD had good soundstage depth & width again the 300B Frankies are king of the road here as well.

In summary: I think the APD is much more accurate than the Frankies and would accel in most any system and I suspect they have authoritive base given the additional low extension power they provided with my mid-high horns. As for me, I think I may have been in the 300B world too long to walk away from the luscious midrange even with their shortcomings in ultimate accuracy. Special thanks to my dealer Koby at HiFi Logic in NJ for his flexibility for working me in.

The Atma-Sphere D's are in good company with the FirstWatt F7, FirstWatt SIT3, Cary 805C, PS-Audio M700, Benchmark AHB2 that have challenged the Frankies.  I will continue to search from time to time for a suitable solid-state tube amp replacement. 

Follow Up... While it sounds like I will never leave the 300B world please note that there is no turntable in my system after 25 years the Innuous streamer enabled divesting vinal 2 years ago and I’m perfectly happy with streaming.

@j-wall

Unfortunately, no I have not tried the PS M-1200 it would be severe overkill for my horn application as was the M-700. That being said I did hear it back to back with the PS-BHK300 on Wilson Sasha DAW and my preference was the M-1200. If you need the power might be a solution especially with the tube rollable input stage.

@williamdc

Funny you mentioned this as it was on my mind for this morning... I will say the cheapo Crown did spank the PS M-700 previously leaving me shocked. I was so sure the PS would crush the Crown that I dug out the Crown box from the attic before installing the M-700s... then 3 days later took the Crown box back to the attic and sold the M-700s.

One last comment then I’ll sign off. I have not been on AGON for about a year and since I was interested in the new Atma-Sphere Class-D I thought I would check to see what others were saying and stumbled on to this thread at page-2. When I secured a home demo opportunity, I thought I would give input to add to the community. That being said, the fiasco that this thread has become with the measurement vs perception "comments / pissing match" has reaffirmed my worst fears of what AGON has devolved into. Worse that small children. I just cannot understand why stating your position and one possible retort with civility is not possible by some. You may be having fun being the bully of the playground, and smarter than everyone else, and while you may think you are teaching others, you are in fact disenfranchising those that are starting their audio journey and corrupting the social space this platform can enable and frankly killing the hobby.

Done & out for another 6 to 9 months.