Tube pre-amp is fine to remove lid. Solid State amp is a very bad idea. The SS amp bias is set according to temperature. Remove the lid and the amp will be all over the map in regards to stability/performance due to too much heat loss.
You must have a verified phone number and physical address in order to post in the Audiogon Forums. Please return to Audiogon.com and complete this step. If you have any questions please contact Support.