The arrangement of the bench where the monitor sits above and the main box stands on the floor beneath doesn't leave any scope for cables to be routed anywhere else other than where they are (and have been for some years!) due to cable length limitations. Ditto keyboard. Wireless mouse is unchanged for a long time. The audio amp stands atop the floor standing PC box. If a completely different sound source (Android tablet) is plugged in using the same amp i/p and cable there is no issue with the sound quality or with the hiss/buzz effects reported yesterday. I have moved nothing knowingly over the weekend so I am still at a loss to figure out what is wrong.
Something inside the PC box is not happy.............
Rans6.........