Okay, here's what I've currently got: Sennheiser HD 598s, being powered by a generation 1 (Jan 2013) Astro Mixamp Pro. I'm absolutely keeping my 598's - I love them to death. I'm debating what the best solution to upgrade my audio is. I'm upgrading my SFF computer, which is my primary listening device, and unfortunately my choice is between either not having a Toslink optical out, or spending $100 more for 4 fewer USB ports. Double-Edit: Never mind, guys. I've been doing some research, both online and with samples, and what it really came down to is when I looked down at the shelf my mixamp is on and realized that Dolby was off... and probably has been for a year. The soundstage on the 598's is just good enough that I assumed it was using surround. Original question for posterity: Spoiler I talked to Astro already, and unfortunately, my mixamp absolutely requires the optical cable to support surround. Their newest offering at $130 can do it just through USB. The important factor here is that I would very much like to keep Dolby Surround. It's pointless for music, but awesome for gaming. So, the question here, I suppose is this: 1) Live with fewer USB ports, save $30, keep my mixamp. 2) Get the new mixamp, give mine to a friend. 3) Get a DAC & Amp or combo unit that gives me surround and good performance for less than the mixamp Budget: Up to $130 Source: USB type A on a desktop. (Sound card not an option, sadly.) Isolation, type, ect - N/A Tonal balance and music tastes: Balanced. I listen to pop, rock, folk, swing, and a lot of Enya. Thanks for the advice, guys! EDIT: Oh, and I can't have a USB dac that just sticks out of the computer, unfortunately. My computer is on one side of the desk and my headphone line comes off the other side - and if I have the line crossing my body, I've learned that I WILL fiddle with it until I destroy the cable. After doing some testing in games, I greatly prefer using my headphones without surround - so unless there's a highly cost effective DAC/Amp that will improve my sound, I'll be keeping what I have, just without the optical cable.