Those scales don't mean anything out of context. On my older Yamaha (currently used to power my M22s in my writing room), going to -40 is scary-loud as the 0 is at the end of the dial! My Onkyo (like Denon) makes it 0=dolby reference (exactly, actually). Old Yamaha at -40 is like new Onkyo at +8 (I measured when I switched receiver).

See Mojo's signature