Music suddenly sounds wrong, no dynamics

Hi All,

Happy for your input on the following. Running an Ayre V5 and K5, source is an old original Musical Fidelity V Dac wired over USB to an even older Macbook, music is stored on an external harddisk.

System has to date sounded very very good. Saving to upgrade to an Ayre QB9.

As of last night, my system can no longer play "complicated" music as it used to do. Diana Krall / voice only is sounding good as always, but with multiple instruments like classical concerts and Coltrane Live in Birdland are completely....wrong. Shallow tones, shallow mid bass, rhythm seems off, very weird. Can't listen to it, so much wrong with it.

Before this happened, I noticed that the speakers were no longer as "pitch black silent" as they used to be.

Any ideas what component has died on me / is fading out here?

Warm regards,

Arie