Has anyone heard or have thoughts on this headphone amplifier? I want to purchase it as a secondary amp in another room for my Grados. Already have the Ming Da - what an amp, BTW, I put on the score from "Chicago" and I swore the bass drum was right in the room with me and right in front!! I...

All: I was wondering what the best tubes were for the DAC 60 and/or the DAC 68. I am currently using the Sovtek 6N1P in my PVC modded DAC 60 and have left the JJ Teslas in the DAC 68. Pacific Valve changes the awful sounding EH 6922 to Sovtek 6922 tube for their modded DAC 60. Anybody...