Best amp for KEF LS50


Looking for best possible amplifier for KEF LS50s. I have tried Parasound Halo A23,  Benchmark's new amp and ,currently the Audio Alchemy DPA-1. So far, Audio Alchemy sounds the best, Parasound next and Benchmark the least satisfying, But, I'm still wanting a better match. I'm looking under $3000, tubes or solid state, new or used, and hopefully not huge and weighing a ton. I would really appreciate recommendations.
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I see I have commented on this thread in the past so I thought I would update.

1) Paraound A23 + LS50 : I thought this was good combo but easily bettered by the next 2 amps I bought.

2) Second best was Peachtree Nova 150 + LS50. Lot of details, not harsh. Can listen for hours. The iPhone USB connection is surprising good with iTunes. I normally listen to FLAC or FM radio.

3) The Benchmark AHB2 + LS50 is my best combo, Just clear and deep view into the music.
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Still love my Rogue Cronus Magnum II with my LS50s, even more so after some careful tube rolling.
I just completed a Pass DIY amplifier project based on using NOS Sony 2SK82 and 2SJ28 VFETs as a complimentary pair in a push-pull Class A amp (https://www.diyaudio.com/forums/pass-labs/276711-sony-vfet-amplifier-2-a.html?). Even though this amp is only rated at a nominal 15 watts per channel into 8 ohms and 20 watts per channel into 4 ohms, this is one of the finest amp pairings I have heard with the KEF LS50s. This amp has a relatively high damping factor of 45, and I believe this contributes to the synergy between this amp and the LS50’s.

With my Audio Research LS7 tube line stage, I have no problems filling my living room with tonally rich music presented in a huge holographic soundstage that I previously thought was only possible with tube amps.

Combined with the spectacular imaging of the LS50’s, I am treated to very engaging music events every time I play analog or digital tracks. I listen to a wide range of music from early choral to jazz to classic rock nd blues. In fact, I was jamming to The Who’s “Live at Leeds” earlier today along with Morton Gould and His Orchestra performing Copland’s “Billy the Kid” and Grofe’s “Grand Canyon Suite.” 

Unfortunately, the Sony VFETs are near-unobtainium, but Nelson Pass does build First Watt Class A amplifiers using new production equivalent (maybe even better) Semi South Static Induction Transistors (SITs). His SIT series of First Watt amplifiers have received excellent reviews and they are worth auditioning with the KEF LS50’s in an appropriately set-up system.