Stax stax ESL-F81 - please help


I am trying to figure out what amps would drive F81 best. I have a Class A 20W custom made ECC88/MOSFET Amp that works great with high sensitivity speakers but fails badly with Stax, McCormack DNA-1 Deluxe that drives Stax fine but is not as fluid as Aleph 3, Pass Aleph 3 works fine but clips at higher SPL and Symphonic Line RG11 that works nicely but does not bring anything special to the table. These are very demanding speakers.

Frequency Characteristics: 40Hz ~ 20KHz (-10dB)
Impedance: 4Ω or full band
Sound pressure level: 73dB (equivalent 8Ω 1W/1m)
Maximum input instantaneous: 300W (equivalent 8Ω)

With impedance all over the place from 2 to 32 depending on the frequency. Any suggestion for under 2K tube or sand amp?
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When they are found for sale, what do the F-81 speakers go for??
and
Are there any ss amps power them well enough??
FWIW, I had good results with a Marantz 8 or a pair of Dyna 70s. I also used a custom EQ+crossover with a sub because the F81s have a weird FR and impedance curve in the low end

I purchased a pair of these wonderful speakers from @justlisten and absolutely love them.  They are a very difficult load for a solid state amp (even the ones made by Stax) unless you are listening at low to moderate level in a small room.  The reason is the peak up to 512 Ohm impedance while having a 73 dB sensitivity.  They really love a high quality tube amp.  I will probably try an OTL at some point.