Pre Amp Help

Hi guys. I am wondering if it is worth the switch to a dedicated pre-amp or a pre-amp/tuner. I currently use my Onkyo Integra A/V receiver as the pre-amp/tuner. I have an Arcam 8SE hdcd/cd player, an Adcom GFA-555II amp, and KEF Reference 103/4 loudspeakers. I use Audioquest interconnects and solid Audioquest bi-wire speaker cables. The Integra receiver is better than most, with a pre-out (obviously), and gold-plated rca connections for the cd, pre-amp out, etc. I like the receiver because of the nifty remote, display etc, but I'm wondering if I'm compromising sound quality. There is presently a reasonable B&K pre-amp/tuner on ebay, as well as an Adcom GTP-500. Any strong opinions??