Yeah it does perform nicely beyond specs, so no complaints there, I just find it odd on a technical level.
but I did notice that it basically tops out at about 1-1.2 kW total power even in 7 ch drive, so perhaps it’s just hitting a max PSU limit or something. Would be interesting to see bridged single channel results, though that’s not very relevant for a 16 channel amp anyway
I misunderstood your point initially. Not "odd" as such imo as it is not that uncommon in the real world, there are just practical limits such as PSU related, that you alluded to.
Theoretically, output should increase 2X when the load impedance is halved, and 4X if the voltage doubles (bridged mode). In this case, 500 W is well below the 800 W theoretical limit, so there obviously are some limitations. Whether it is a PSU, heat dissipation related or other issues, would depend in the design, that we are not going to know. Gene could probably find out from Marantz, if he has a way to contact their design team.
As you mentioned, PSU is most likely one of the "limits", especially for multichannel amps, but again, there are likely other factors.
Like the double down thing, the quadruple thing in the case of BTL configuration also would rarely result in the theoretical gain in output if you look through the specs of many such amps. Some amps (example: AHB2) do get very close though, but would also likely be rated at (or measured on test benches) higher distortions at or near those upper limits.
