36 Australian Hi-Fi
ON TEST Arcam CDS50 SACD/CD/Network Streaming Player
˹˹˹ƖŘˁʊǒǔǞƖƋɁȧCONTACTDETAILSMANUFACTURER’SSPECIFICATIONSBrand: Arcam
Model: CDS50
RRP: $1,499
Warranty: ThreeYears
Distributor: AdvanceAudioAustralia
Address: Unit8,509–529ParramattaRoad
LeichhardtNSW 2040
T: (02) 95610799
E: [email protected]
W: http://www.advanceaudio.com.au̴ Outstandingconnectivity
̴ Outstandingperformance
̴ Outstandingoperability̴ Bluetooth
̴ Headphoneoutput
̴ RearUSBinputusing48kHz/24-bittestsignals.There-
sponseswereexceptionallyflat,asyoucan
seefromthegraphedresults.FortheCD
section,theresponsewas20Hzto20kHz
±0.13dB.Inter-channelphasewasalso
exceedinglylow.Thephaseerrorresults
fortheDACsectionhavebeengraphed,
soyoucanseeforyourself.FortheCD
section,therewasa 0.02°errorat16Hz,
noerroratallat1kHz,anda 0.05°errorat
20kHz.Theseerrorswouldbetotallyinau-
dible,evenunderidealcircumstances.
Graph1 showsTHDat1kHzfora 0dB
recordedsignalfromCD,andalthough
therearesomedistortioncomponents
visible,they’reallmorethan100dB
down(solessthan0.001%)andthisis a
‘worstcase’signal,sincenocommercially
recordedCDswillhavesignalsrecorded
onthematsucha high(0dB)level.In
fact,mostofthesedistortioncomponents
werecausedbytheArcam’sownoutput
stagebeingpushedtothelimitbythe0dB
signal,becauseyoucanseeinGraph2,
wherethelevelofthetestsignalhasbeen
reducedto–10dBthatabsolutelyallthe
distortioncomponentshavedisappeared
exceptforthethirdharmonic,whichis
a converter-relatedcomponent,andthis
harmonicis sittingdownat–117dB(0.
0.00014%THD).
Ata recordedlevelof–60dB,theoutput
oftheArcamshowedtheusualgranula-
tionnoiseonewouldexpectwhena DAC
was converting a low-level undithered
signal. Granulation noise is also present
in Graph 4, where the test signal is an
even-lower –80.59dB (again not dith-
ered) and you can see that in addition
to the granulation noise, the DAC has
introduced some odd-order harmonic
distortion. So what happens when the
test signal is dithered? You can see this in
Graph 5, which shows the Arcam CDS50
reproducing a dithered 1kHz test signal
recorded at –80.70dB. There’s just the test
signal at the left of the graph, then no dis-
tortion whatsoever, just a clean noise floor
down at –140dB. Excellent performance.
The same effect is demonstrated in
Graphs 6 and 7 which show an undith-
ered signal at –89.46dB (Graph 6) and a
dithered signal at –90.31dB (Graph 7).
You can see the distortion that’s visible
in Graph 6 disappears completely in
Graph 7. However, you can also see that
when the test signal is not dithered, the
noise floor is lower than it is when the
signal is dithered. This is the ‘penalty’
you pay for dithering a digital signal—an
increase in the level of the background
noise—but when that background noiseLABORATORY
TEST REPORT
Frequency Response: 10Hz–20kHz ±0.5dB
Harmonic Distortion: <0.0008%
Signal/Noise Ratio: 122dBA (balanced)
Output Voltage @ 0dB: 2.2V (unbalanced)
Output Impedance̵ ̨˞ί͒ƯŢċðŗðŢČěē͓
DAC: ESS9038 32-bit/192kHz Delta-Sigma
Supported sample rates
Optical: 32kHz, 44.1kHz, 48kHz, 88.2kHz,
96kHz
Coaxial: 32kHz, 44.1kHz, 48kHz, 88.2kHz,
96kHz, 176.4kHz, 192kHz
Bit depth: 16-bit – 32-bit
USB: USB 2.0 High Speed (480Mbps)
Ethernet: 10/100Mbps
Wireless: 802.11b/g/n
Power Consumption: 20W (max)
Dimensions (WHD): 433×87×283mm
Weight: 5.3kgis 140dB down, as is the case here with the
Arcam CDS50, the increase is not important,
because even at the higher level it will be
totally inaudible. Remember that it’s only
test CDs and digital test signals that are not
dithered, precisely so they can show DAC
performance—all digital music signals will
be dithered. You can read an excellent article
about what dither is and how it works at
http://www.avhub.com.au/dither
Graph 8 shows the output of the Arcam
CDS50 when it’s reproducing a 20kHz signal
recorded at 0dB. You can see there’s a little
interaction with the sampling frequency that
results in unwanted signals up around 24kHz,
36kHz and 40kHz, but all the signals visible
on the graph are close to or more than 100dB
down and at frequencies that are in any case
so high they’re inaudible (and most especially
at these low levels!). The same was true when
the Arcam CDS50 was reproducing a CCIF
IMD test signal (Graph 9), however due to
the lower recorded level, the sidebands and
sampling artefacts are even lower in level,
more than 110dB down (0. 0.00031% THD).
The unwanted signal that’s regenerated down
at 1kHz (being the difference signal between
the 19kHz and 20kHz test signals) is sitting
118dB down (0. 0.00012 % THD).
Arcam is using a very steep high-cut filter
on the output, which is shown in Graph 10,
which uses a 630 pulse per second test signal
to look at the filter slope.Newport Test Labs measured the output of the
Arcam CDS50 as being a bit more than 2.23
volts from the unbalanced outputs, and a bit
over 4.45 volts from the balanced outputs, so
it’s a true balanced output. Channel balance
was an outstanding 0.0001dB, which is excep-
tional, while channel separation was also out-
standing, with a best result of 148dB at 1kHz,
and a ‘worst’ of 133dB at 20kHz. I’m not sure
that I’ve seen any CD or SACD player (or DAC)
have such good channel separation at 20kHz. It
shows excellent circuit engineering.
The frequency response of the Arcam
CDS50 was measured for the CD section using
a 16-bit/44.1kHz test signals and for the DAC