Well, I am happy to report that I think the T-amp does a more than acceptable job driving the HE-6. My set up for this test was Denon CDP digital out > Yulong D100 DAC > Ray Samuels Audio Stealth (as preamp) > T-Amp > HE-6. The T-Amp drives the HE-6 to much louder than I can stand with no distortion, and sounded really very good doing it. This is potentially an easy and inexpensive way to add a speaker-amp for driving the HE-6, and could potentially be driven right off of a source.
I was actually very impressed with this combo - much better than I expected. The sound is better off the speaker taps of the T-Amp than it was via the headphone out of any of my amps except the Leben. I'm going to have to try the HE-6 directly off of a Rotel 100 WPC power amp I have and see how that sounds.