Onkyo TX-NR801 Receiver "turn music sounds becomes distorted" Questions

...music on zone 2 speakers has become distorted at all volume levels. Just started happening, could the zone 2 amp be going bad. Sound from the main speakers is perfect. if you have a main speaker ...

...turn them up. If the sound is getting extremely distorted, the Receiver is attempting to operate above it's maximum output. The scale is an average, but because music recordings are often mastered at ...