Advice for a choice

Thanks larry5729.
I will take into consideration your illuminating answer

Not so on Marantz. I've examined their schematics. They pay very close attention to important details.

Many of their products use op-amps made from discrete components designed for the purpose rather than generic OTS parts that require far too much feedback.

They also pay particular attention to power supplies. Instead of generic 7xxx regulators which have HORRIBLE impedance curves, they use well designed purpose built circuits.

IMO, Parasound and ARCAM are nice but over-rated. I found the Parasound [?model?] to vary a fair bit over temperature as the heatsink bias temperature coefficient was not well matched to the driver circuitry.

If you buy used, you won't have to worry about Sound United. If you are looking to stream your music, I would highly recommend the Marantz NA6006 Network Audio Player/DAC. I have the NA7004 which I found on US Audio Mart several years ago, and I would never go back to a tuner.

Read the information about the NA6006. Not only can you stream with Spotify Connect, Pandora, SiriusXM, Amazon Music, TIDAL, but you will have access to Internet Radio via V-Tuner, which will give you over 20,000 channels from around the world.