I simply cannot recommend using tube amps of due frequently hard wired tubes as well as poor total harmonic distortion.
If you are using the amp exclusively on a computer with a USB connect then I would recommend the CENtrance DACport. It is $400, but has both a DAC and amp stage in it. It would drive your Q701 just fine and has much better total harmonic distortion than the Little Dot MK II.
The Matrix M-Stage is the better of the two amps. The M-Stage does not appear to be USB fed so keep that in mind.
The Headroom Total Bithead is what I use in that price point which works tremendously well and has been with me for over 7 years. It runs only $150 and less used.
Edited by NA Blur - 10/30/11 at 5:03pm