Hi,
This is my first post once i just found this amazing website.
I'm currently looking for an amp to use with my Grado SR60. My sound sources are an Iriver H340 and a Cowon A2.
I was looking at warehouse123.com to the Audio-Technica AT-HA2 Headphone Amp because i live in Brazil and they ship it here.
Can somebody tells me if these is a good amp? Is any other store that i should consider looking before buying at warehouse123?
Thank you in advance, epaludo !!!!!!

It's not great... 85 dB of SNR is quite low, especially for headphones, but hey, it does the job.

I'd suggest you build your own headphone amp.

Good luck,
T.

A S/N ratio of 85dB is quite good. That is well below almost all music. Mine is rated at 89dB. I have to turn it up all the way, far above where I could listen to any music, to hear anything at all of the amplifier. There is never any suggestion of amplifier noise when listening to any music. Of course, S/N ratio isn't the only aspect to consider, but 85dB should never be a problem.

what andy said.

Andy, which amp do you have ?

Graham Slee Solo

It depends on the headphones. If their impedance and sensitivity are such that their output is extremely loud, the amplifier noise can be annoying because it will be 85 dB below a signal of 120 dB SPL, while it should have been 85 dB below a signal of 100 dB SPL.
Usually, the noise of an amplifier is permanent and doesn't depend on the volume setting. But I don't know if this applies to headphone amps.

I'm sure that the basic amplifier noise itself is constant; its the full system I am listening to as I turn up the volume. With the volume all the way down, which most likely means the input shorted, I can detect nothing through my (according to the manufacturer specs) most sensitive headphones, which are a fully closed design.

I have a number of devices with headphone outputs and a variety of headphones with various (manufacturer claimed) impedances. I can't really notice any difference in background noise that depends on the headphones but I obviously can't try all possible headphones. I suppose it is possible that some transducer might produce a high enough sound level for me to actually hear something of this headphone amplifier's background, perhaps if I were in a sound isolated location, but I find it hard to imagine it ever becoming a factor when listening to music.

I love Audio-Technica. Try http://www.audiocubes.com/

Also consider frequency-response. Usually 5-22khz is good. 44khz is great if you can afford it.

Thanks for all your help guys.
With a few search i decided and ordered a Pocket Amp 2 Version 2 from Electric Avenues. It costs me U$60 and looks like a pretty good amp, one of the bests in the price range ...