I had this exact issue with a client who supplied his own Denon. I think it was a 3802.

The Denon's remote has a button for 6 channel input, one called mode, another called analog.

I found that if I issued a "6 channel input" command followed by a "mode" command, the receiver put itself into "Auto," no matter what mode it had been in before. Since he has ONE place where he wants to go into 6 channel, I use that macro as part of EVERY input choice. For his 6 channel input, I use that macro followed by "6 channel:"

6 channel
mode
6 channel

Sounds dumb, but the dumbth* really belongs to Denon.

The Marantz might have something like this, where a particular sequence will put you where you want to be.


*"Dumbth" is a brilliant book written by Steve Allen almost twenty years ago, talking about the totally stupid things people do because we have not learned to actually think.