I'd also be curious to know if someone has tried to drive headphones with the speaker out of a new T-AMP? This new generation of amplifiers seems to be very hot, but I can't find one with a headphone jack...
I am a total cynic when it comes to headphone amps - indeed, amps of any kind. Over 30 years, I've had a string of low/medium/"lower high end" amps in my system, and I subscribe to the prevailing view at uk.rec.audi0 - all half decently disigned amps (which includes most on the market) sound the same. So don't get me started on cables