Best isolation under a big receiver ?

I found Herbie's Tenderfeet made a nice difference under my tube integrated. If your receiver is over about 45 pounds you'll need something more heavy-duty though.

Receiver weighs 60 lbs, and my cables are already off the floor. I am a little leery of hardwood slabs due to reports of dynamics being killed.

I've been using Brightstar under my Integrated and my CD player with (IMHO) spectacular results since day one use and it is sonic improvements that you can hear!

Just picked up am AVR 307
I'm a newb, so what I'm gathering is I should put a large wooden block under this receiver and it will improve the sound along with getting the cables off the ground?

Timtim, there's not hard & fast rule for isolation. different solutions work for different people. For example, I have my amp sitting on its factory feet but I've got the amp sitting on my home-made amp stand which is a sandwich of hard maple & granite.
What I might also suggest is that you open up the amp & apply vibration damping sheets (can get these at Parts Express or a local car audio shop) to as much of the internal metal chassis as possible - vertical inside walls, underside of top plate, any exposed metal on the bottom plate. This damps the chassis & prevents it from ringing.
Try different isolation platforms - hardwoods are better (hence my choice of hard maple). Granite is also good but make sure that it is not suspended in air where it can ring (as it rings pretty good!). Damp the underside of granite with a cork sheet.
FWIW. YMMV.