I have a Theta Ds-pre that I purchased new. How much of an improvement in sound could I expect by using something like an Arcam Avp-700 as a processor. Currently I have BW 804's, Bryston 4bsst, Denon 2900 and I am using the Theta as a transport and as a pre-amp pass thru. I dont think I want to upgrade the Theta- 8500.TIA