Reddit mentions of FiiO E9 Desktop Headphone Amplifier and Dock for E7 USB DAC

fiio e7+e9 amp combo It's a Headphone amplifier

The HD650's have a really high impedance (650ohm), so it probably wouldn't have enough ooomph to push them.

Fiio has a separate amp that you can dock with, but it's kind of ugly, see here:

http://www.amazon.com/gp/product/B004M172FY/ref=as_li_ss_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B004M172FY&linkCode=as2&tag=nocor04-20

Basically the E7 or E17 would sit in there and get a boost.

I haven't researched the higher-outputting dac+amp combos - you might have to buy separately. I'd post this question on head-fi.org - they are the most useful people around for these matters.

http://www.amazon.com/gp/aw/d/B003N0XDT4/ref=redir_mdp_mobile my preferred amp, and also means that if you upgrade to some high impedance headphones you can always grab http://www.amazon.com/gp/aw/d/B004M172FY/ref=redir_mdp_mobile to attach it to later on.

So, right now Emotiva have a 10% off sale, which makes the AirMotiv 5 tremendous value, at $404. Link here.

While probably not my personal first choice, an amp/DAC combo that does what you want is the Fiio E9/E7. While the new E9K/E17 combo is probably "better", there's a $100 difference that brings it out of your price range. Link here - see "frequently bought together".

Finally, good speakers deserve to be placed properly - if you're planning on using them in front of a computer. If you're tight for floor space, something like these will do nicely, but if you have the floor space, something like this will probably be better.

Edit: Strike my recommendation for the E9. Its 10 ohm output impedance makes it a poor match for your HD 598's. Thing is: There are very few products in a reasonable price range that allows you to use them both as a headphone amp and a DAC - the next step up is the Nuforce Icon HDP, but that's $350.

If you want an amp, the Fiio E7/E9 Combo is really nice.

This will be my second time typing this out, since I hit the fucking Browser-Back shortcut on my mouse.

I wouldn't recommend the Koss Plugs as a set of mixing phones, even while travelling. The clarity is simply nonexistant. My suggestion is just to use them as a second pair to check out your bassline before you finalize a track. For something more balanced, you might want to set aside an hour or two and drag your eyeballs over this thread over at head-fi.

As an off-the-cuff recommendation, Velodyne vPulse have gained quite a reputation in the under-$150 category. they have plenty of bass output, but it's much tighter than the Koss, no muddiness. They also get plenty of compliments on the detail in the midrange/treble.

/r/Audiophile is a great resource, as is /r/Headphones, but to save yourself from shame, I will tell you ahead of time, anything called a soundcard will almost certainly get you laughed out.

Puts on top hat and monocle, raising a cup of tea with the pinky out

>A gentleman uses a DAC with a seperate Headphone Amplifier.

In all fairness a soundcard is nothing but a DAC with a built-on amp, though the integrated amp circuits are terrible, in terms of audio reproduction.

You can get a DAC and feed an amp with it, or you can get a DAC/Amp combo, which is a popular place to begin, and is a great solution for a personal digital studio, especially if you use your laptop as a creative device away from home. The most recommended (for good reason) is the FiiO e7. It performes both the DAC and amplifier functions, as well as including an input jack and a battery so you can stick it in your pocket and connect it to your ipod/phone/whatever and increase the quality of your portable listening as well (This bypasses the DAC and only uses the amp). The only drawback to the e7 is that the amp is kind of puny. Mind you it is still more powerful than whatever is built into your devices, but it can leave you wanting if you have some high-end, high-impedance headphones. To solve that, you can either get a FiiO e9 amplifier to leave on your desk and dock the e7 to when you are at home, or you can pick up a FiiO e17 which is almost identical to the e7, but with more juice to the amp. You mentioned a speaker setup at home, so you would also want a FiiO l7 line out plug so you could run the un-amped output of the DAC to your speakers. Keep in mind, none of this passes as "Audiophile grade" hardware, but it's certainly (digital) studio quality.

All in all, an e7 and a pair of vPulse IEMs would set you back about $150, give you the low-end you need, a full-up system you could pack in your pocket while you're on the move, and also boost the quality of your 8400's, and whatever monitors you choose at home.

I'll get off my soapbox now. Hopefully that gives you a head start on your research.

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^tiny ^disclaimer: I don't work for FiiO, I'm not trying to sell you FiiO stuff, I don't even use FiiO myself. They just have a great reputation, and market at a reasonable price-range.

If your'e looking at portable amps I recommend this.

Edit: Forgot that it was a two piece set, this is the portable that goes a long with it, they work perfectly hand in hand.

I use this
I have the same headphones as you do, they drive them perfectly fine.