Originally Posted by Skylinestar
I wonder which has a cleaner RCA pre-out? The Marantz SR6010 or Denon X4200?
My usage will be mainly movies with an AVR with a stack of Crown XLS2002 amp.
Is the advantage of 32bit DAC (in X4200) over a 24bit DAC (in SR6010) clearly audible in movies?
This seems to be a popular comparison. If your priority is zone 3 or dual video (TV + projector), then the Denon 4200 is likely to be the better choice. The Denon also has a bit more amp power, but if you're using external amps then that wouldn't matter.
However, if audio playback is the highest priority, then the Marantz 6010 might well be the better choice. You've asked about the pre-outs and the Marantz has HDAMs rather than IC based op-amps and also has multichannel analog in, which is rare in the 2015 models (only the Denon 7200WA or the Denon pre-pros have it, I think).
Put simply, for the Marantz HDAMs, someone measures individual components with a meter and bins them, and then they populate the HDAM section with these discrete components which match up closely with each other rather than using an IC chip.
I don't know whether they hand-populate the HDAM section of the circuit boards or whether they bin components and wave solder them in batches. Anyway, here are pretty pictures of the difference between the two circuit boards from earlier in this thread:
You can chase the link to a more detailed review if you like. (Note, review was against 2013 models, but the preamp board holding the RCA connections hasn't changed much in 2015 AFAICT; although the HDMI boards got reworked, of course.)