Loss of Bass voice-

This problem occurs when a bass voice (usually Super Bass) is triggered (played) sixteen or more times in a row, one note will be muted every sixteenth time. There have been no successful corrections found except to swap out the PCB boards until a working set is found. A minor incompatability exists between different software versions that have had updates misapplied.

Hi freq noise-

See Yamaha Service News E608 on the website. This modification also reduces the hi freq noise present on the audio outputs.