Just read through this entire thread again. It's clear that the output signal clips at 1.4 volts with any combined use of internal and external amps.
Here is the question I think a lot of people have about the Denon 4700 (and other Denon's as well)
Based on this graph, is it a safe assumption or can it be assumed that with internal amps off the SINAD of the output voltage remains as high or near the curve on this graph with 5 channels connected to an outboard amp? Another way of asking: It appears to me that it's SINAD is 97 @2.3 volts with internal amps off. How would the SINAD of that signal be affected with 5 or 7 channels out? Amir? Others?
- Graph Omitted -
There is no way to turnoff the internal power amplifiers.
OK my bad, but I'd bet you know what I mean. Using the 4700 as a preamp/controller only, with 5 or 7 preamp channels out to an outboard amp what would the SINAD be at 2.3 volts?
The forum has science in the name. Making chains of assumptions that are unlikely to be verified and then betting on what other people think doesn't fit well with science. It isn't even clear what "Safe assumption or can it be assumed," means.
Without measurements or at least schematics of the X4700H, the characteristics of preamp channels that have not been measured is guesswork.