PMA-900HNE
amplifier
$1,049
Used market: $755*
Specifications
3 of 5 values have a recorded sourceExpert Audio Engineering Commentary
Headroom Notes
Both published figures are kept because only together do they mean anything. 50 W is into 8 ohms across 20 Hz - 20 kHz at 0.07 % THD; 85 W is into 4 ohms at a single 1 kHz tone and ten times the distortion. Denon's own product page leads with the second one: 'this amplifier delivers 2x 85W'.
Thermal Behavior
The manual splits the load allowance by terminal: 4 - 16 ohms on speaker set A or B alone, but 8 - 16 ohms when A and B run together. Two pairs of 8 ohm speakers wired to both sets is the case people actually hit, and it is the case the 4 ohm figure does not cover.
What the datasheet actually says
Quoted verbatim from the manufacturer’s own page, with the date we checked it. We state what is printed, not what anyone intended by it.
«Rated output power: 2-channel driving (CD → SP OUT) 50 W + 50 W (8 Ω/ohms, 20 Hz - 20 kHz, T.H.D. 0.07 %) 85 W + 85 W (4 Ω/ohms, 1 kHz, T.H.D. 0.7 %)»
One amplifier, two power figures, three measurement conditions changed at once: the load halves from 8 to 4 ohms, the signal shrinks from the whole audio band to a single 1 kHz tone, and the permitted distortion rises from 0.07 % to 0.7 %. Denon's own product page for the same unit prints '50W per channel (8 ohms)' in the feature list and 'delivers 2x 85W' in the body text, so both numbers describe this amplifier and only one of them is comparable with a full-band rating.
checked 8/5/2026* Estimated with the depreciation fallback (~72% retained value). · checked on 8/5/2026