Anybody have any experience with Parasound PHP850 or Parasound pre's in general (modest ones, I'm sure the Halo is wonderful)? How would this compare to an Adcom GTP 500 or Yamaha C series? I'm just getting into separates & haven't had these pre's or been in position to demo them. Really having issues with indecision on this. Trying to stay under $200. (pre will feed into a 200wpc PS Audio amp to Vanderstein 2ce's) TIA.