Overheating? Turn off lights and look at tubes for red plating.
The volume of my speakers going down by itself and going back again in a minute or two
I just upgraded a used Audio Research tube Preamp and a power amp. I found that the The volume of my speakers going down by itself and going back again in a minute or two. What could be wrong? Both amp and preamp are used. I had my speakers for 20 years. Never had the issue before. Help!