The reason I asked about source components is - My bedroom audio system is just an Adcom GFA-545II amp and an Adcom GCD-575 CD player, which has its own volume control. It was cheap, simple and sounds very good with my JBL S38 speakers. Since I have only one source and it has a volume control, I can do without the preamp.

The reason I asked about dimensions is, an Adcom GFA-535 is only 60 watts per channel, but it's a quality 60 watts. It sounds good and it's plenty of power for small rooms. I used to have one in a 12 x 15 x 8 room and it sounded very good. It could save you money as compared to the GFA-545 and leave more room for a GFP-555 preamp. That said, though...I do have a GFA-545II and I like it very well. I got such a bargain I couldn't pass it up.