Marantz DV6500 Audio RightMark Test Results

I tested the production player on both the modded 5.1 channel Front Left/Right analogue outputs, as well as the unmodded 2 channel analogue output, using Audio RightMark 5.5 and an E-MU 1212M as the capture card.

First off, the results on the unmodded 2 channel analogue output, at 24 bit resolution and 44.1, 48 and 96 kHz sampling rates:

Unmodded player test results

As you can see, the unmodded 2 channel output measured reasonably close to spec, with a dynamic range of around 98-100dB, and a THD+N of around 0.0015-25% (which is slightly better than published specs). IMD+N and Stereo crosstalk figures are good. The output voltage was very close to the 2Vrms reference.

Unfortunately, the player did not fare as well on the modded 5.1 Front Left/Right outputs:

Modded player test results

First of all, the output voltage is around -3dB below reference (no doubt due to the op amp analogue stage being bypassed), resulting in a slightly higher noise floor and correspondingly lower dynamic range, plus higher THD+N, IMD+N and stereo crosstalk.The following graphs are all based on measurement of the player playing back test tones at 96kHz 24-bit. In these graphs, the cyan plot is the modded Front Left/Right output, the green plot is the unmodded 2ch output, and the white plot is the E-MU 1212M measuring itself in loopback mode.The modded Front Left/Right outputs seem to attenuate both high and low frequencies more aggressively than the unmodded 2ch output, with the frequency response down -1dB at 30 Hz, and also -1.5dB at 20kHz:

By contrast, the unmodded 2ch output is flat to 20Hz, and only down -0.75dB at 20kHz.In a conversation with Joe on these results, Joe indicated that the slightly more aggressive high frequency attenuation for the modded output was intentional, and deliberately tuned by ear for euphonic playback. Joe suggested the attenuation at low frequencies was due to the E-MU 1212M having an input impedance of 10 kohms, and would be a lot less for a normal pre-amp input at 100 kohms. If this is correct, it would suggest that the player needs to be matched with an appropriate pre-amp, and is not recommended for use with passive pre-amps.Looking at the noise level, the JLTi has a noise floor at least 10-20dB above the E-MU 1212M capture card. The most significant contributor to noise is residual 50Hz (fundamental plus harmonics) from the power supply. In addition, there are significant spikes at around 5kHz, plus several out of band spikes clustered around 30kHz.

And this graph shows THD+N (at -3dB FS):

Intermodulation distortion for a standard 60+7000 Hz signal:

As can be seen, stereo crosstalk is uniformly good across the whole frequency spectrum:

Unfortunately, the modded 5.1 Front Left/Right analogue outputs seem to exhibit a problem with the intermodulation distortionsweep above 1kHz:

In contrast, the intermodulation distortion for the unmodded 2ch output appears normal:

Finally, switching the player into “Audio Exclusive” mode (by pressing the “Audio Ex” button on the front panel) improves the audio characteristics slightly: dynamic range is increased by about 0.1dB, THD and IMD+N improve by 0.0001% and stereo crosstalk improves by just over 1dB. These improvements are unlikely to be detectable by the human ear.