audio racks and power amps

I was in a similar situation with my Krell KAV-250a. It's definitely better to not let it get ANY hotter than it does when outside a rack, even if it has no sides or back. (Mine is that way as well...)

More air circulation will most likey be needed. However, you can be the judge by checking that the heat build up is not too much. Too much would be significantly more than its normal operating temp when it is in an open space. I was running a rather warm amp in a similar arrangement and ended up removing the amp from the rack. In my opion its not worth shortening the life of your amp or possibly burning your house down. John