Advice on Setting Up A Laptop-Based Audio System?


Hey, I'm looking to set up a workspace audio system based around my Apple Powerbook G4. I've got about 100 GB of uncompressed audio on an external hard drive. I currently have Monsoon planar speakers and matching subwoofer hooked into the laptop through the 1/8" audio out, which soundsokay, but I think I could do better.

I don't have a PC card slot in the Powerbook, so I'm limited to a USB audio connection. I'm not looking to hook this system up to my "big rig" -- it's just for my workspace. I was looking to bypass getting an amplifier, unless it's fairly small.

I was thinking of going with some powered mini-monitors and maybe some kind of adapter/DAC in between, but I'm space-constrained and not looking to spend more than say, $600 total.

Any suggestions?
marc_dc
I have about 160gb of uncompressed CD/AIFF music, and I was NOT impressed with the Transit, terrible drivers, and the output via optical was sub-par compared with my rotel RDV-1060 dvd player. We're not talking about a 'subtle' difference either, my non-audiophile friend who was over with the Transit was like "wow, that really SUCKS in comparison." This was after we spent almost 2 hours getting the stupid thing to output at 44.1/16 since it INSISTED on trying to go to 48khz (sounded even WORSE). From reading a lot on HeadFi and elsewhere, I too recommend the Firewire Audiophile (supposedly better drivers) or look into Edirol (Roland) such as the UA-25. Too bad you don't have a pcmcia / cardbus slot, as I've also heard very good things about the Echo Indigo card.

I'm looking to do the same, with my 15" G4 Powerbook - I may just go with the Echo Indigo - but my only worry is being partially internal to the computer, that it might pick up hard-drive / processor noise. If that's the case I'll try something like the Musical Fidelity X-DAC v3 and find a decent digital out via PCMCIA or external, via FW or USB, similar in function to the Transit, but a Transit will surely NOT be part of the system. I used to use a G5 w/ built-in optical but now I need the portability of the Powerbook, dammit if only Apple put optical on the PB, and it's too bad the Airport Express has mini-1/8" optical as I've yet to see a quality TOSLINK (boy is THAT an oxymoron) cable in that format...
The Transit that I use is modded and outputs coax S/PDIF. It is superb sounding. I use Foobar and ASIO4ALL plug-in to avoid Windows mixer.
I fount the roland ua-1d works better than the m-audio. no drivers necessary, fuller sound, coaxiaql and toslink in and out. the airport express sounded better than the m-audio, the roland beats them both
The ua-1d samples only at 48kHz. The M-Audio transit will pass 44.1 bit-perfect and 96.
audioengr, i found the oposite to be true re: the m-audio on my powerbook, stupid thing kept going up to 48k no matter what i set in the driver.....

i gave up and picked up an apple airport express... signal as follows:

CD ripped to AIFF via iTunes -> Airport Express -> optical -> MF TriVista -> MF X-CAN -> Grados

i'm lovin' it ;)