Philip:
Sorry I don't have time just now to give an exhaustive description of my recommendation, but I suggest you try to hear a Purity Audio Design preamp. I believe that the 'Reference' model is in that price range. My experience with the Ultra GT version is astonishing. I use large-scale symphonic music as one of the more stringent tests, and this preamp is 'it' for me. It has all the imaging qualities that one would expect, along with slam, separation, definition, and yet, grace, that one would hope for in one unit. Overall, the realism and 'presence' of this preamp will grip you. An additional benefit is the ability to tweak the sound by using different tube manufacturers for the (2) 12AU7 tubes. Another huge benefit is that Bill Baker, designer and owner of Response Audio, is one of the great guys in the business. You have been given many options here. If you are seriously interested in learning more about my experiences with my Purity Audio Design preamp, I will offer you my cell phone number for greater details of sonics. Good luck.