I have both the Audio Alchemy DDP-1 and the PS Audio Directstream DAC. Both are darn good. I think the PS Audio sounds significantly better (as it should given the price difference and the absence of features like analog inputs and a headphone amp). The Audio Alchemy has an analogue preamp and a decent headphone amp built in. The PS Audio DAC has just a volume control on it's output, but it is a very good volume control that did not degrade the sound in any way that I could detect. I used the PS Audio direct to my power amps for several months and thought it quite wonderful. Still, when I swallowed hard and shelled out for the PS Audio BHK preamp, the improvement was undeniable and well worth it. It sounds more life-like, real, organic, etc. So my experience supports what ricred said above. That said, you can always get a preamp later, if you start with a DAC with volume control.
