Mark Levinson 5805 underpowered?

Hi. I have a 5805 but have 3 issues. In simple terms:
the amplifier feels like it lacks power by comparison to other amplifiers. For instance the naim supernait 3 rated at 80w is noticeably more potent than the 5805 rated at 120w into 8 ohms. So I’m pushing it harder. The naim is at 9 on the clock to achieve 80db whereas the 5805 is in excess 50 on the 80 limit, say 2 on the clock. This was measured as an A/B comparison in the same room. The analogue moving magnet amplification is woefully low as is the headphone output although acknowledged that is class a. Does anyone know what is going on? Is there a setting that can be adjusted or is this just a poorly performing amp in terms of power, it sounds wonderful by the way.