The EF2A is a great little usb dac/amp and has mullard tubes installed. I confess, I know little about them, but I can find out more if you are inquisitive. No drivers are required to use it with your computer, just plug it in and enjoy :) This is a fun amp/dac and I think a pretty cool way to dip your toes into the world of tube amplification. The EF2A will also come with the stock tubes that it was shipped with.
I'm open to any combination of trade and cash, shoot me an offer and I'll get back to you asap. I'm pretty quick about responding, except during the day because...well work is a pain, but it pays the bills ya know :)
EDIT 1: I think $100 is a little low, unless you would like me to remove the mullard tubes and just send the stock tubes with the amp. I have had a few offers around this mark.
Edited by TheNewCanMan - 4/2/13 at 7:26pm