As well as my headphones guess (DSP powered and input via speakerlink obviously) I will also add the Sooloos dongle that was unofficially anounced a while back then subsequently denied (as if the dealer had his hands slapped by M). This will also make Sooloos available to non M amplification.

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