Originally Posted by Fruit
The hiss may not be due to ground loop issues nor coming from the Marantz receiver.
Experience tells me that hiss noise is a characteristic of amplifiers with less control of (more distortion at) higher frequencies and/or perhaps poor power supply and/or poor PSRR.
The symptom your setup is experiencing could have been excited by your environment and poor shielding of your RCA audio cables. I think this because RCA connections go to un-balanced circuits.
Other than modifying your amps, ensure you have the best quality RCA cables to minimise unwanted stray signals reaching and exciting your amps.
I'm pretty sure I tried using my high quality RCA cables that are driving my LCRs in this experiment, but I might try again.
The minuet guy's post has got me wondering if I've got an issue like his. This is a refurbished unit after all. And another thing about that hiss. It's noticeable from the MLP mostly because I have the subs pointed directly at the MLP, and fairly closely too. I can probably re-arrange them so they're not pointed directly at the listener and I imagine that will help a lot. The sound they emit is VERY directional.
This and a few other issues have me debating stepping up to full separates because I realized I could just add another Behringer amp and use the Emotiva for the remaining channels that the monolith doesn't cover, but then I noticed that the 7704 pre-amp uses much of the same architecture as the 7012 (same DAC anyways, and not a top-tier one at that) and (as mention below), I'd essentially be paying twice as much to go to the pre-amp. Can't quite decide if that's worth it, but I would get XLR outputs and all of my amps have XLR inputs (not fully balanced designs, but the XLR design inherently reduces line noise anyways, right?)
I do have a 90 day return policy on the 7012, but I think I may have really scored on a deal with this thing. Didn't really think about it much but I did get it on Prime day and it was last one like this (refurbished, "renewed" as per Amazon) available. So far every other one I've seen has been selling for almost twice as much. Think I might just count my blessings and live with small inconveniences.
But if there's a significant SQ difference between the 7012 and the 7704....