I guess my amp got a problem , everytime i start playing cd no sound come out from right channel, after 2-3mins the sound come up but on and off for a another 2-3mins and works perfectly after that. Its not cdp since the same problem happen when i select to another input. Fyi, my amp is a hybrid integrated which is using 2x6922 tube at pre-amp side. Is it because of one of the tube failure?