Verbose? Not at all. We're just freely exchanging some ideas about our shared passion, and, that, my friend, is what Head-Fi is all about.
Hmm... Since I rarely listen while on the go, I have never attempted to learn much about portable amps, and, thus, am not well-versed on the portable amping options that are available. However, considering that the HE-6 does need about two watts per channel, it just isn't suited to any ordinary portable solution. There may be some extant high-powered portable solutions out there, and, if so, perhaps a fellow Head-Fier can weigh in on the issue.
I really feel as though you should try to get your hands (and ears!) on a pair of the HE-500, for they are a nice cross between my re-cabled T1 and my LCD 2.2. To my ears, the HE-500 has greater musicality than the HE-6, which, on the other hand, has a bit more clarity. Complicating matters is that you are a bit unhappy with the graininess that you are hearing with your T1, and, therefore, this gives me pause when recommending the HE-500 to you. I absolutely love my HE-500, but they are in no way clearer than the T1.
Although I think the HE-500 would be a nice cross between your HD650 and your T1, another idea is to re-cable your T1, for this would likely send all graininess on a first class ticket to oblivion. (Re-cabling certainly did that for mine.)
By the way, don't be fooled by the HE-500's $699 pricetag... It is truly a world-class headphone. You may already know this, but, just in case you do not, the HE-6 used to be priced at $1099 and the HE-500 was priced at $899; later, for the sake of market separation, the HE-500 was dropped to $699 and the HE-6 was raised to $1299. They actually use the exact same magnets, and many (like me) actually prefer the HE-500--even if the prices were the same. (Steve Guttenberg of CNET and Srajan Ebaen at 6moons also prefer the HE-500 to the HE-6. Mr. Guttenberg summed up his HE-6 / HE-500 review thusly:
"The HE-6 is the top-of-the-line HiFiMan headphone, and it certainly had superior resolution to the HE-500 and the Audeze LCD-2, but for my taste the HE-500 is more fun to listen to than the HE-6. Resolution isn't the be-all and end-all quality for me, but it might be for you."
Resolution is clearly (pun intended) not the be-all and end-all quality for me, either, but one look at my signature line makes that evident... That you, like me, chose the T1 over the HD800 tells me that this also holds true for you (not to mention the fact that you own a pair of of HD650's.)
So, in the final analysis, if you want improved clarity, just re-cable your T1. If you want to find something that blends the desirable traits associated with your T1 and your HD650, try the HE-500. For the price point, they are a preeminent bargain, and even if they were $1000, I think that they would still be worth every penny.
(I hope that David can weigh in soon... Just as Dan Quayle "was no Jack Kennedy" in the realm of politics, I am no David Solomon in the realm of headphones. )