S
LAB REPORT Denon DCD-2500NE Super Audio CD Player
32 Australian Hi-Fi http://www.avhub.com.auAll measurements made on the DCD-2500NE SACD player
were obtained using a standard Philips test CD (SBC-429)
so all data was 16-bit/44.1kHz. Using this disc, Newport
Test Labs measured distortion at 0dB recorded level, the
results of which are shown in Graph 1. You can see that all
distortion components are at or more than 100dB down
(0.001% THD), so detailing the levels of the individual
harmonics is essentially an exercise in technicalities, with
the second harmonic coming in at –105dB (0.00056%), the
third at –100dB (0.001%), the fourth at –120dB (0.0001%),
the fi fth at –113dB (0.00022%), the sixth at –135dB
(0.00001%) and the seventh at –128dB (0.00003%).
Obviously, the results at 0dB were excellent, but musical
discs are not recorded at 0dB, because there needs to be
some headroom for peaks, so it’s instructive to look at
the distortion results at lower recorded levels that refl ect
what would be on a music CD. Graph 2 shows the Denon
DCD-2500NE’s performance at –10dB recorded level and
you can see there are just two harmonics visible in the out-
put—a second harmonic at –135dB (0.00001%) and a third
harmonic at –111dB (0.00028%). This is an exceptionally
good result.
But exceptionally good got even better at a recorded
level of –20dB, where Newport Test Labs measured just
one single harmonic distortion component in the DCD-
2500NE’s output at –121dB (0.00008%). I don’t recall any
CD player—or SACD player—or DAC, delivering such good
performance at this level.
The performance at –60dB was about standard for a
high-quality player, with all the ‘grass’ on the noise fl oor
being due to the fact that the –60dB signal on the test CD
is not dithered, unlike all music CDs, which are dithered.
Nonetheless, all the ‘grass’ was more than 120dB down
(0.0001%). The remarkable effect on distortion of dither-
ing is shown graphically in Graphs 5 and 6, which both
show performance with a 1kHz signal at a recorded level
of around –90dB, but with one test signal dithered and the
other not. In Graph 5, when the test signal is not dithered,
you can see third, fi fth, seventh and additional harmon-
ics. The second harmonic is at a real level of –110dBLABORATORY
TEST RESULTS
Graph 1. THD @ 1kHz
@ 0dB recorded level.
[Denon DCD-2500NE
SACD Player]Graph 2. THD @
1kHz @ –10dB re-
corded level. [Denon
DCD-2500NE SACD
Player]Graph 3. THD @
1kHz @ –20dB re-
corded level. [Denon
DCD-2500NE SACD
Player]Graph 4. THD @
1kHz @ –60dB re-
corded level. [Denon
DCD-2500NE SACD
Player]-140.000.00 Hz 4000.00 8000.00 12000.00 16000.00 20000.00-120.00-100.00-80.00-60.00-40.00-20.00dBFS0.00 .EWPORT 4EST ,ABS-140.000.00 Hz 4000.00 8000.00 12000.00 16000.00 20000.00-120.00-100.00-80.00-60.00-40.00-20.00dBFS0.00 .EWPORT 4EST ,ABS-140.000.00 Hz 4000.00 8000.00 12000.00 16000.00 20000.00-120.00-100.00-80.00-60.00-40.00-20.00dBFS0.00 .EWPORT 4EST ,ABS-140.000.00 Hz 4000.00 8000.00 12000.00 16000.00 20000.00-120.00-100.00-80.00-60.00-40.00-20.00dBFS0.00 .EWPORT 4EST ,ABS