I would use the fixed output into the integrated and rely on the integrated's remote for volume control. This must be acceptable to Quad or the CD player would not work period. You can even use the variable output but try the fixed first.
How to connect the Quad 99 CD-P to PrimaLuna
I just bought a QUAD 99 CD-P from Audiogon. I have a Primaluna Prologue One. I am not sure how to connect the cd player to the amp. The cd instruction manual says that one should never try and connect the Quad directly to a power amp. But it doesn't mention anything about an integrated amp. So the question is: can I connect this cd player directly to my PrimaLuna using the fixed output(there is a variable output also) feature of the cd )?