He's probably talking about this
"After speaking with Denon we got clarification that the A110 does give you a specially tuned receiver by Denon Master Engineer Takahashi, Yuuki, a 5 year warranty (up from 3 years on the X8500H), and upgraded components in key areas that affect sound quality like specialized capacitors, lower impedance traces, and a more rigid chassis"
Yep, each of the Denon and Marantz's "sound engineers" (wonder if they are licensed?) apparently tuned their products using some sort of PEQ and/or tune control modules, and/or harmonic injection/mixers to achieve the intended "sound signatures" of their own, such as punchier, brighter for Denon, warmer, more musical, for Marantz. They presumably have done extensive studies to find out how many people would prefer the Denon sound and how many the Marantz sound..
. I guess I am just guessing though..
.
If I guess wrong then I have no idea how they could come up with such unique sound signatures for each (never mind comparing to other brands such as Yamaha, Sony and Pioneer's, when D and M's have virtually identical power amps, and preamp/processor section except one has the HDMI unity gain buffer stage that is just a buffer, not an equalizer.