when i put my ARC sp3a1 into my system, i never looked back at the adcom gfp565. what you need in a preamp is transparency. the line stage is the HEART of the audio system. so jolida, cj, vtl, arc, whichever, tubes in the preamp will make your system, even with a ss amp such as my adcom 555II.
This is where I am at Tommy. I have the GFP 565 in front of the GFA 5500 and keep thinking the next step up has to be going tube pre. So you like the ARC that much more? Did you try others?