tstan, I am a little confused here, but will offer some comments anyway. I am not clear on what the Yamaha receiver is doing in this chain,...are you using it as a pre-amp? You also mentioned that your Sony player "crapped out",...are you using a different cd player?
To answer your questions, amps DO have significantly different sounds, soundstaging, etc. However, I would not be sure the different sounds are due to the amp. It sounds like you changed rooms, cd players, wires and interconnects, and possibly other factors. The only way to be sure the different sounds are due to different amps are by listening to the exact same system, in the exact same room, and changing ONLY the amps. If your friend will let you, borrow his Adcom and put it in your current system and compare. If you still like his better, sell your Aragon and buy a used Adcom. I personally think Aragon makes a great amp for the money,...but it is what YOU like that sounds "good".
To answer your questions, amps DO have significantly different sounds, soundstaging, etc. However, I would not be sure the different sounds are due to the amp. It sounds like you changed rooms, cd players, wires and interconnects, and possibly other factors. The only way to be sure the different sounds are due to different amps are by listening to the exact same system, in the exact same room, and changing ONLY the amps. If your friend will let you, borrow his Adcom and put it in your current system and compare. If you still like his better, sell your Aragon and buy a used Adcom. I personally think Aragon makes a great amp for the money,...but it is what YOU like that sounds "good".