None's required, but many "lesser" products than Meridian processors have HDMI switches already. Some of them are on replaceable modules, which is almost for sure going to be cheaper to upgrade than buying an HD621 or whatever comes after it.
As HDMI switches go, the HD621 is pretty pricey (though yes of course it does more than just select 1 of N HDMI signals), not that Meridian's customers are likely to be that sensitive to that. There's an argument that keeping all the digital video electronics out of the audio processor might be a good idea, however, at least if there's any analog stuff.
From what I understand, Marc Koval is now also a dealer as well as repair. Gary
My Kit: Trinnov Altitude 32,Oppo BDP 203, Sony 600es, Martin Logan Neoliths Mains with VTL Siegfried II's, ML CLX's, ML Renaissance, 5 ML Theaters,13 ML Vanquish, 6 ML Edges, 6 ML Axis' 8 Velodyne DD-18+'s, Pass Labs 600.8,Pass Labs 160.8, Pass labs 160.5, Bryston 14B-SST, 6B-SST,6 Bryston 9BSST^2's, 14' Stewart Screen, Berkely Alpha DAC RS
Well I tried the store locater, called a few, most not carrying Meridian. Saw the note about Marc being a dealer and everything started moving quick. Marc delivered an HD621 quickly, took my 98 in trade for parts and helped complete the install.
I am very happy with the result. One item I am not sure about are the settings in the Oppo. For audio, the choices are LPCM, bitstream and Auto. Currently running in Auto mode and the sound it is at least as good as the G98. Another confusing issue is the DVD Audio selection is greyed out on the Oppo setup menu even though it sounds great.
G68J, HD621, Oppo 103d, 3xDSP5000, 2xM60 Rears, D2500, Linn LP12, Nova Phenomena phono amp Brad
I use LPCM on the Oppo as I run a satellite and cable boxes thru it which output bitstream. I understand bitstream is decoded but not up sampled/apodised downstream in HD621 or processor. Also you need to output hires Bluray output LPCM to play these codecs.