Marantz 6000 OSE direct to amp?

I think a passive preamp, basically a box with a volume knob and and a pair of in/outputs, would be the right solution for you. The English brand Creek makes a good, affordable one, and I've heard some good things about Jolida.
I only wonder about the digital variable output on the Marantz. Normally, sound quality deteriorates with most digital volume controls at low outputs. My own Marantz (63 KI) sounds better with the output at max through the preamp than directly plugged in in the poweramp, so I'm a bit baffled that the preamp in the Classé sounds worse.
Just make sure, if you run the Marantz into a passive preamp, you turn the output to the max and use the preamp for levelcontrol.

You could try something like an in-line 10db attenuator from Rothwell. It would lower the volume across the entire range of your volume control.

Enjoy,

TIC

Thanks for your replies. Satch, I will try your suggestion first as I have not used the player in that fashion. Obviously the cost of that solution is very appealing.
Cheers,
DG