When you visit Head-Fi.org, take a look at the review I wrote on Consonance Cyber 20. The review is a few years old. I've not actively looked into the headphone scene for the past two years so things may have changed quite a bit.
I had started out looking at the Earmax Pro. Then I got really involved with Head-Fi.org and organized several local meets. I brought all my front end gear to these meets so I could try out different amps. But ended up buying this one, and two other amps, Cyber 30 (using 2A3s) and Rudistor RP-5.1cav (tube hybrid). Each amp has it's own special personality. I have both HD600 and HD650. I especially enjoy the HD600 w/ Cardas headphone cable and the Cyber 600 combo for Jazz and female vocals.
I believe there's also a review of the Cyber 20 at Soundstage as well.
FrankC
I had started out looking at the Earmax Pro. Then I got really involved with Head-Fi.org and organized several local meets. I brought all my front end gear to these meets so I could try out different amps. But ended up buying this one, and two other amps, Cyber 30 (using 2A3s) and Rudistor RP-5.1cav (tube hybrid). Each amp has it's own special personality. I have both HD600 and HD650. I especially enjoy the HD600 w/ Cardas headphone cable and the Cyber 600 combo for Jazz and female vocals.
I believe there's also a review of the Cyber 20 at Soundstage as well.
FrankC