The M6's are a very nice speaker. There is a lot of slick tech and materials used for its manufacture.

You could look for a AC200 (think preamp) it allows you to add a number of sources and gives you access to a number of set-up features as well as control of bass & treble etc. Meridian just dropped the price to $1500 this past spring. You might contact some Meridian dealers as they may have a used one or a demo for even less.

818v3, DSP7200SE, F80, Roon Nucleus Titan.