It's been a long time coming, but I finally purchased my first headphone amp this week, the luck device in question being a JDS C421 with the OPA2227. I didn't really think that I would need a headphone amp considering my current collection is fairly low impedence-wise (highest being 44 ohms), but because I'm at the office for a good portion of my day or on the go, I was left feeling that my cans could benefit from an external amp since my iPod seemed to have great difficulty driving my 440's.
Well, finally got the amp in on Friday so I've been putting it through its paces. I immediately noticed the sound open up a lot as opposed to my iPod's amp section. It's really nice finally having my headphones properly driven now! The soundstage seems to have open a lot, and the highs don't seem muffled like before, really helps during busier sections of music. The low end seems to benefit as well, much smoother sounding all around. Even my IEMs get a noticeable boost in sound quality, which was a great surprise.
On my desktop setup, I noticed a similar difference in audio quality. The Xonar DX sounded better than any other source I had on hand by far because of its very solid DAC, but it does seem to open up quite a bit when paired with a headphone amp via lineout. I again noticed that busier sections of music (dense parts of rock/metal especially) had greater clarity than before. Maybe it's just placebo, but oh well. I'm going to throw it my signal chain from now on.
I did mess around with the bass boost switch a wee bit. I'm not a huge fan of these kinds of eq options, but this one did not seem all that bad compared to some software solutions I've heard. I won't be keeping it on all of the time, but it'll be cool for a change of pace once in awhile.
In the end, considering that the C421 benefits my music listening for both portable and home usage, I'm very happy with this investment. It's a bit more expensive than some other options and it doesn't have a DAC, but I decided to invest a bit more in the amp section because that's what I'll be using the most anyway. I'll probably be investing in some higher impedence cans later this year, so it'll be interesting to see how the high gain section can handle those loads. From my research, I think this little guy is up to it.
The only issue I've noticed so far is that I'm experiencing a bit of hiss if I were to max the volume out on the amp with my iPod plugged in (no music playing of course!). Though I have a feeling that's more of an issue with my source, since without anything plugged in, I noticed no hiss from the headphone jack. This hiss is noticeable on both my IEMs and full sized cans
Edited by TheChillburger - 8/6/12 at 7:25am