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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If I decide to go with OTL tube amp what should be ideal specs? Any amp suggestions? I just want to see what the market is.
I have F-81's and Stax DA100M Amps which work very well together. The DA100M's were designed and built to drive the Stax F-81's. However, I have found that my Radford TT100 Solid State/KT88 Valve Hybrid actually drives the F-81's better than the DA100M's! In fact the Radford is one of the most amazingly dynamic and staggeringly powerful 100W amplifiers I have ever come across. it's a true audio work of art. The Stax amps can run out of power at higher volumes causing significant distortion on more complex programming which is both annoying and potentially damaging. I have never had this problem with the Radford driving the Stax. My advice would be to truely make the Stax sing you need a powerful Valve amp. OTL would probably work well. Good luck and have fun experimenting.
This thread is out of date but I may as well chime in. First, pay attention to Kentaja, he fixed my Stax F83's (which did indeed have blown resistors and consequent panel damage). This is a man who knows his business. Second, the amps I've been using to drive them are the Futterman OTL3a.s They are a magnificent match, but the amps run out of steam in the bass, where the impedance drops (unusual for an ELS). I ended up using a subwoofer, with a steep crossover at 100Hz. I couldn't be happier now. These amps are still available used if you try hard. An incredible combination.
When they are found for sale, what do the F-81 speakers go for??
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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