You’re Krell has surround sound analog inputs (7.1) from what I can tell.
Those inputs were made so that your Krell wouldn’t become completely obsolete.
Now is the time to utilize those inputs (in my opinion).
You would need a Blu-Ray Player that performs internal decoding and that has analog outputs.
Looking at Crutchfield.com here is one option: The Panasonic DP-UB820
You should be able to connect the analog outputs from the Panasonic to your Krell 7.1 analog inputs and get the latest surround sound format, like DTS HD-Master and Dolby True HD (except for Dolby Atmos).
If by chance you are interested in Dolby Atmos, you would need to get a new AVR and additional Dolby Atmos Speakers.
That is probably the cheapest way to go that I can think of.
Hope that helps.
Jay