I’m using a Marantz HD CD-1 to drive my new-to-me Rachel and I find that I don’t need a gain stage to fully drive the amp but it'd be real nice to have single knob device to control for the different levels on the CDs. I had intended to use a Schiit Modi 3+ DAC as a switcher but I’ve found today that I prefer the sound of the analog output of the Marantz to the coaxial input of the Modi. This Rachel came with variable outputs and they are HOT, just as Steve had told me they would be, so the input control to my sub is barely opened. Still, the character of the tube output thru the sub is wonderful and I’m very pleased.
I'll be manually changing the input cables when I get the desire to listen to my music library but so far running CDs top to bottom has been enough to satisfy me.