Personally, I am a friend of tube amps --> but only in tube radios of the 50ties and 60ties.   For my headphones I prefer transistor amps.   By the way: Is the tube amp sound really "warm" because the tubes are getting warm/hot and are glowing?  

Yes - go for the Q701 - with an amp like Schiit you will not be disappointed. You have made a dicission for a very good head-fi gear!

@vaibhavp   Instead of the Q701 you could consider the K701. The K701 is round about 100 $ / 100 € less expensive than the Q701. Here are a lot of discussions, if the Q701 is better than the K701. Some say that they hear a difference (Q701 better) others say there is no difference.   I have...

  Sorry - I guess we have a misunderstanding here. Developng a complete new high quality DAC chips IS exepensive. But as long as the already existing DACs are already technically fully developed items, there is no technical need to develop new ones. And the already existing DAC chips are not...

  One remark, please: After having read tons of reviews, I had understood that there are basically no differences between DACs of different manufaturers. If I got it right, DACs are technically fully developed items. And a DAC chip only costs some cents - so there is no need for manufacturers...

  100% ACK.   And for those who don't want to diy: Head'n'HiFi is also selling ready-to-use O2 amps.   I ordered an O2 in the beginning of this year at Head'n'HiFI and I am still satisfied.     ---- edit: typo corrected