My question is, would a single channel output stage problem cause attenuated output for headphones as well as the main speakers? Here is some background. I have a Sony STR DE-597 that I am using to play only music through two channels with a powered sub. I have noticed recently that the right channel is playing very quietly and adjusting the balance only serves to attenuate the other (left) channel can't boost the right at all. Here is the crazy part, the problem also shows up when I connect a pair of headphones. A google search reveals that this is a common problem with 12-16 year old sony receivers, but there is no real answer posted anywhere.