Assuming the shelf is just a little wider than the amp I don't think that is enough for that amp my friend. It is almost 300W at idle.
Now, if you have plenty of width, say 5" or more on each side then you could be OK.
The 507 is 90W at idle and the 509 is 150W. I own the former and I would not attempt a hotter amp with only 1." I have it on top of a shelf and use riser feet to increase the air flow beneath the unit.
I checked the manual I have for the 507. They do not have minimum distances, but state "... do not install the equipment in a confined space such as a book case or similar unit."
Now, if you have plenty of width, say 5" or more on each side then you could be OK.
The 507 is 90W at idle and the 509 is 150W. I own the former and I would not attempt a hotter amp with only 1." I have it on top of a shelf and use riser feet to increase the air flow beneath the unit.
I checked the manual I have for the 507. They do not have minimum distances, but state "... do not install the equipment in a confined space such as a book case or similar unit."