I seem to recall MrSpeakers talking about how they were working with various amp vendors to make more ESL headphone amps available for their electrostatic headphone. Did anything ever come of that? Anything? So what's out there now besides Stax for electrostatic headphone amps (not speaker/amp combos)? I see HifiMan has a new amp coming out that might be an option for Stax owners. I'm thinking its time to upgrade from my 353X but don't know what's out there that isn't five thousand dollars.