Originally Posted by akwok I'm torn between a Headroom Micro DAC (My Onkyo already does a fine job I think), and the DPS.
IMO you get a lot more sonic improvement/dollar with a source upgrade than a PS upgrade. However, I've never heard the Micro DAC or your Onkyo, so I don't know how much upgrade we're talking about here. Headroom has a 30-day money back guarantee, so if the Micro DAC doesn't meet your expectations you could always send it back and spend the money elsewhere.
Since (according to your sig) you don't have the Lite yet, why not get it and enjoy it for a while before worrying about upgrading?
I have a Lite with the Elpac, and it simply rocks. The way I look at it, I'd need to spend $500 to get an amp of equal quality to the Lite with dedicated PS. So, someday when I'm dying to drop that kind of money on a new amp, I'll get the PS instead and save $300.