I agree with you, except OP’s need to turn the volume up so high, and I cannot find any specs for MM and MC gain.
The difference of MC S/N 72db to MM S/N 84db is substantial.
Denon specifically mentions their DL-A110 cartridge with 0.3mV signal strength.
Perhaps OP errantly had his MC button in the MM position which skips pre-boost for weak MC signals, that would explain the need for max volume.

