There's a good chance the switches on the back of the Proceed amp would not allow you to switch between sources, but serve to short pins 1 and 3 (assuming pin 2 hot) so as to prevent noise being picked up on the unused side of the balanced input when running unbalanced. Some balanced-input amps use switches, and some use jumpers to accomplish this goal. If this is true of the Proceed, then the balanced and unbalance inputs are not isolated from each other and would not permit switching sources. If you have an ohmmeter, check for continuity between the center conductor of the unbalanced jack with pin 2 of the balanced jack. If there is continuity in both switch positions, then source selection would not be possible. DO NOT do this unless your system is shut down and unpowered!!!Regarding your H/T vs A/O (audio only) dilemma, Sfinnel and Val comsa both explained, in slightly different ways, the best solution I know of to work around our desire/need to have a "pure" two-channel audio system coexist with, and even share some components with, a home theater setup. I suspect there are many audiophiles that want both, and I'm not convinced H/T and two-channel listening are mutually exclusive. When considering the dual preamp scenario, it helps to think of the main front channel outputs of your digital processor as merely another source to the analog preamp. In this way, you're not compromising the integrity of your two-channel system, though you have made the H/T mains secondary to the analog preamp. The negative effect of running your H/T mains through the added circuitry of a quality analog preamp is negligible for movies, and a small price to pay for the integrity of your two-channel system. Having a unity gain input or setting on your analog preamp makes this processor/preamp scheme more elegant, but as Val comsa described, it is not the only way. The unity gain setting allows you to control your H/T levels without having to fool with a second volume control on the analog preamp and, in H/T mode, its only contribution is to select the main channel outs from your processor. If you want to be able to listen to the same source both straight and processed, this can be accomplished if the source has dual outputs, or through the use of a (dare I say it?) "Y" splitter. A graphic block diagram would sure help clarify this whole matter! How about this instead? H/T Mode: Source to be processed > Processor > Analog preamp (set to unity gain) > Stereo amp. T/C Mode: Source NOT to be processed > Analog preamp > Stereo amp. The sources and their signal paths are separate up to the analog preamp, where you switch between modes. I can't think of a way to depict one source available to both modes through a "Y" because of the divergent signal paths, so I won't try! Hope this helps, and good luck.