I found the HDMax in the end, but was a bit mystified when I typed in 'hdmax' into the search box and eBay converted it to a search for 'humax'.

Meridian owner since 1992
Prime & PSU, Focal Elear headphones, Roon (ROCK 8Gi5 NUC), Explorer 1 & 2, F80. 200/203, various Sonos (via Roon).