Like the Grado PS1000, the T1 has boosted upper-bass and trebles, and a recessed mid-range on a relative basis. With the wrong amp, regardless of price or quality, you could end up with a tonal imbalance with the T1, i.e. a bloated bass that muddies up the mid-range and a screeching treble that will drill holes through your ear drums.

If the T1 is your only headphone, I would recommend the MAD Ear+ HD ($750), a modest tube amp with forward and liquid mid-range and rolled off bass and trebles, that would produce a tonally balanced and very musical sound with the T1. I have had this combination for a few years now and cannot find anything that could top it at three times the price. The Woo WA2 may be a better amp, but it will not sound better with the T1.

If you plan on getting other headphones beside the T1 (and the Grado PS1000) in the future, then the MAD Ear+ HD will not be versatile enough to adapt to all headphones. For most currently popular cans like the HD800, LCD2/3, HE-560/HE-6, TH-900..., there are several very versatile amps that can drive them very well. They ain't cheap. The ones I know will work based on my own experience are: HeadAmp GS-X Mk2 ($3,000) and Bakoon HPA-21 ($2900) for SS amps; for tube amps, the Woo WA5-LE (~$4500 with good tubes) and EAR HP-4 ($5,000). I was told that the Eddie Current 2A3 and the Apex Teton, both at around $5000 are also great choices but I do not own them so I can only recommend that you check them out. Ah, I forgot: the new McIntosh MH100 ($4,500) with a strong claim to versatility may be worth checking out as well.

If you can accept some sonic compromise, the more moderately priced Eddie Current Super 7 ($1,400) and the Apex Peal/Volcano ($?) will also work well with a large number of headphone. But if you plan to have only the T1 (and the Grado PS1000), which is a very picky headphone, it will be very hard to beat the MAD Ear+ HD.