Originally Posted by lithium1085
I have been looking at the hifiman EF2A with great interest but my concern is the lot of people who complain about it in the forums. I can see that you have it in your amp list, so maybe you can answer a few of my conerns.
1) Does it work on 64 bit windows?
2) I heard a lot of people complaining about too much gain on it, is this true?
3) did you get it from the head direct website or from amazon or somewhere else?
4) Do they have a good enough customer support thing if something goes wrong?
5) Have you had problems with the power supply?
There's 2 models, EF2 and EF2A, i'm running Windows 7 64bit and i can confirm EF2A works, i can't vouch for 64bit Vista or XP but it should be the same, people reported the earlier EF2 had compatibility problems with 64bit.
The amp is indeed very loud, driving a low impedence headphone like my 25ohm denons you only need to turn the volume knob a fraction to drive them to a listenable level, but that's not a major concern, the HD598's are 50ohm so won't be as sensitive.
Got mine from http://www.ampcity.co.uk/dacs/dac-amps-2/head-direct-hifiman-ef2.html with 1 year collect and return warranty, only place in the UK to buy it as far as i know, after a year you'd have to go through head direct i'd imagine.
The power supply works fine for me, it's a 2 pin one though so not compatible with UK plug sockets, but a travel adaptor from amazon fits the bill perfectly.
All in all i'm very pleased with it, the stock chinese tubes were terrible but after upgrading them i can say the sound is amazing. If you wanna try some other tubes have a look at the following.
Raytheon 6AK5W http://www.ebay.co.uk/itm/1955s-Matched-Raytheon-JAN-CRP-5654-6AK5W-Strong-NOS-/230664773037?pt=Vintage_Electronics_R2&hash=item35b4b11dad#ht_672wt_1139
Mullard M8100 http://www.ebay.co.uk/itm/M8100-CV4010-6AK5W-MULLARD-NOS-MATCHED-PAIR-/310282214423?pt=UK_Consumer_VintageAudio_RL&hash=item483e42dc17#ht_500wt_1156
There's many more tubes but you can get into that later.
*Edit* i've been assuming you're from the UK, dunno why lol, whichever country you're from look for the relevant power adaptor.
Edited by ilikepooters - 8/28/11 at 2:25am