Some of the CDs that I own are from the early days of CDs, the days when recording engineers were very careful not to approach the 0dB level. This was a good thing, given the level of experience at the time, but it also means that I have a number of MP3s that are fairly quiet.

My current work machine unfortunately has an inadequate amp on the sound card, so even with all the volume control sliders on 11, I can't get enough volume.

I have a set of Altec Lansing speakers on my desk that can achieve impressive levels of sonic masking, so using the headphone jack on those isn't really a solution.

Does anybody know of a nice headphone amplifier with good sonic performance, preferably with volume control?

Or should I just stuff a decent sound card in the machine, and get better volume and performance? Or use a USB sound card?