peniku8
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With the recent price drops of Denon AVRs in Germany (349€ for this particular model) I decided to upgrade my current stereo setup to a surround system.
This is the EU model, which, unlike the US version, does not have pre-outs for front left and front right. I have active mains however, so I will be modding the AVR with impedance balanced, 18dBu capable XLR outputs. More on that later.
In all tests I fed the AVR via HDMI and used the pure-direct mode. A notable observation was that it starts clipping beyond -1.5MV.
Amplifier Tests:
8 Ohm power: 140W
Dynamic Range: ~107dB
2ch 8 Ohm power: 110W
4 Ohm Power: 205W
2ch 4 Ohm Power: 150W
2 Ohm Power: 245W
I did not test more channels at 2 ohm since the manual only specifies 8 and 6 ohm and I was afraid to damage something.
I have a seperate 'power over time' test outside of REW:
Burst headroom 1ch driven:
Burst duration: ~20ms, dropping in level from the very beginning.
Sustained power is the power at the end of the test duration (3s). Burst power shown here is the power at the beginning of the test (which is not super useful, since it's so short). Highlighted region (white) is 20ms (after which it's already 1dB down). Power is calculated RMS from the peak voltage value, which means eventual distortion is not taken into account. Sustained power figures here are similar to the measurements in REW (a little lower since this does not allow any distortion with my method to derive power from the peak values).
Typically I also include power over time graphs but it's not very interesting for this amp so I'll skip that.
Some amplifiers reverse the polarity of the second (or every other) channel internally (and than reverse it back to normal again at the output) for better stability in the power supply, so I wanted to test if I could measure a difference in the first channel if I reversed the polarity of channel 2.
For reference, here is the normal 8 Ohm test with 2 channels driven again:
Now with the 2nd channel inverted:
Interesting! The distortion hump around 15W disappears entirely. It seems like Denon doesn't use this trick in their AVRs, unlike many pro audio manufacturers do. To me, it would make sense to do so on the 2nd channel of every channel pair, altho it doesn't matter in terms of fidelity. With regular music content, this kind of distortion will not be audible. Still, if additional performance could be had by swapping two cable pairs then why not?
Frequency response: -3dB from 1Hz-60KHz
Load dependency (none) and output impedance (0,17 Ohm):
THD vs Frequency:
THD vs level XLR out (@18dBu max; Zout 200Ohm):
Spectrum @-88dB THD+N:
Dynamic Range: 109dB
IMD: no anomalies
Schematic to convert amp outputs into impedance balanced XLRs and convert the amp's maximum output voltage of ~43V to 18dBu (~6V):
I haven't used the amp yet as my decision to get a 5.1 setup was a little spontaneous, so I have to build a center and two surrounds first before I will listen to it. Sadly only the 3x00 and up models come with Audyssey XT32, but my mains have a flat in-room profile on their amplifiers so I'm not very concerned about this being an issue. They also go down to 16Hz in my room so I will be using them as a subwoofer replacement.
And happy new year everybody
This is the EU model, which, unlike the US version, does not have pre-outs for front left and front right. I have active mains however, so I will be modding the AVR with impedance balanced, 18dBu capable XLR outputs. More on that later.

In all tests I fed the AVR via HDMI and used the pure-direct mode. A notable observation was that it starts clipping beyond -1.5MV.
Amplifier Tests:
8 Ohm power: 140W
Dynamic Range: ~107dB

2ch 8 Ohm power: 110W

4 Ohm Power: 205W

2ch 4 Ohm Power: 150W

2 Ohm Power: 245W

I did not test more channels at 2 ohm since the manual only specifies 8 and 6 ohm and I was afraid to damage something.
I have a seperate 'power over time' test outside of REW:
Burst headroom 1ch driven:

Burst duration: ~20ms, dropping in level from the very beginning.

Sustained power is the power at the end of the test duration (3s). Burst power shown here is the power at the beginning of the test (which is not super useful, since it's so short). Highlighted region (white) is 20ms (after which it's already 1dB down). Power is calculated RMS from the peak voltage value, which means eventual distortion is not taken into account. Sustained power figures here are similar to the measurements in REW (a little lower since this does not allow any distortion with my method to derive power from the peak values).
Typically I also include power over time graphs but it's not very interesting for this amp so I'll skip that.
Some amplifiers reverse the polarity of the second (or every other) channel internally (and than reverse it back to normal again at the output) for better stability in the power supply, so I wanted to test if I could measure a difference in the first channel if I reversed the polarity of channel 2.
For reference, here is the normal 8 Ohm test with 2 channels driven again:

Now with the 2nd channel inverted:

Interesting! The distortion hump around 15W disappears entirely. It seems like Denon doesn't use this trick in their AVRs, unlike many pro audio manufacturers do. To me, it would make sense to do so on the 2nd channel of every channel pair, altho it doesn't matter in terms of fidelity. With regular music content, this kind of distortion will not be audible. Still, if additional performance could be had by swapping two cable pairs then why not?
Frequency response: -3dB from 1Hz-60KHz

Load dependency (none) and output impedance (0,17 Ohm):

THD vs Frequency:

THD vs level XLR out (@18dBu max; Zout 200Ohm):

Spectrum @-88dB THD+N:

Dynamic Range: 109dB

IMD: no anomalies

Schematic to convert amp outputs into impedance balanced XLRs and convert the amp's maximum output voltage of ~43V to 18dBu (~6V):

I haven't used the amp yet as my decision to get a 5.1 setup was a little spontaneous, so I have to build a center and two surrounds first before I will listen to it. Sadly only the 3x00 and up models come with Audyssey XT32, but my mains have a flat in-room profile on their amplifiers so I'm not very concerned about this being an issue. They also go down to 16Hz in my room so I will be using them as a subwoofer replacement.
And happy new year everybody