Hello everyone -

Long-time lurker here --I'd forgotten my original username, but this forum has been incredibly helpful with my Q's in the past, so I figured I'd come to you again.

I've been happy with my home setup for the past 3-4 years, but I'm itching to upgrade. Can anyone recommend like components that would a step-up from what I currently have, namely for the amp? Ideally I'm spending $500-600 or less for each item, preferably purchasing used, but I could go higher if it makes sense.

MY CURRENT SYSTEM:
B&W 601's s3
NAD C320BEE integrated amp
Denon DVD5900 Universal player (for all disc formats)
Channel Islands VDA-1 DAC (for Airport streaming)
Rega P3 turntable (don't need to upgrade)
Kimber speaker cable and interconnects

Some thoughts that may help: 1) This is a NYC apartment setup so levels are typically medium, occasionally loud, and bookshelf speakers are necessary; 2) Listening is roughly 40% CD/SACD, 35% iTunes streaming (via Airport), 25% vinyl; 3) All genres but plenty of jazz.

Thanks everyone!

Best,
Clapton