Using Headphone amp as a Preamp ? Any good ??

Some of them are quite good. Check with the folks at Headfi.com or headwize.com for more details. Of course, it would have to have rca outs, controlled by the volume. some headphone amps have RCA pass-thru, don't know if that one has a pre-amp out, but it is suppossed to be one of the best headphone amps.

I'm in agreement with Swampwalker that Head-fi is the best place to find a lot of well informed opinions on this question. I've tried my Sugden Headmaster as a preamp and was not terribly impressed, but I don't have experience with other preamps in the same general price range. As compared to the Bel Canto SEP1, well, there was no real comparison - the Bel Canto was leagues ahead in every respect.

I am using my Linn Majik as a preamp. I tried swapping in my Headroom Maxed Out Home to serve as a preamp (which the Headroom literature says can be used as a preamp), and the headphone amp did not come close to the Majik. This is a pretty darn serious headphone amp vs. the pre section of a one-step-above entry level integrated, so I think that's instructive, albeit it's only one data point.

I almost bought a McCormack Micro Integrated Drive (one is listed in the classifieds now), which is designed for both headphone and preamp use. I'd be very curious about that piece's preamp performance, although I wouldn't be inclined to expect too much unless the optional, heavier-duty power supply were part of the mix.