LAB REPORT
28 AustralianHi-Fi ˹˹˹ƖŘˁʊǒǔǞƖƋɁȧ
Themeasuredfrequencyresponseofthe
YamahaCD-S300wasextraordinarilyflat,as
youcanseefromthetenthgraphaccom-
panyingthisreport.Thefirstthingtonote
whenlookingatGraph 10 is thateach
horizontallinerepresentsa differenceinlevel
ofjust0.2dB,meaningthatthetotalrangeof
thegraph,fromtoptobottom,is onlyone
singledecibel(1dB).So,althoughtheYamaha
CD-S300’sfrequencyresponseappearstoget
a bit‘squiggly’androlloffabove10kHz,that
roll-offis fromthe0dBreferencelinedownto
just–0.14dBat20kHz.ThisputstheYamaha
CD-S300’smeasured‘normalised’frequency
responseat20Hzto20kHz±0.08dB.Note
alsothattheplayer’slow-frequencyresponse
extendsdownto2Hz...thisjustisn’tshown
onthegraph,whoselowestdisplayfrequency
is 20.56Hz.
AnotherviewoftheYamahaCD-S300’s
frequencyresponsecanbeseeninGraph
7, whichshowstheplayer’sresponsetoan
inputsignalat 630 impulsespersecond.On
thisyoucanseethelow-frequencyexten-
sion,butalsothefrequencyresponseabove
20kHz,whichrollsofftobemorethan80dB
downat25kHz...notanissueasthehighest
frequencythat(theoretically)canberecorded
ona CDis 22.05kHz(i.e.,halfthesampling
frequencyof44.1kHz).
Channelseparationwasexcellent,with
NewportTestLabsreportingmeasuredresultsLABORATORY
TEST
REPORT
Yamaha CD-S300 CD Player — Laboratory Test Results
Analogue Section Result Units/Comment
Output Voltage 2.1105 / 2.1336 volts (Left Ch/ Right Ch)
Frequency Response See Graphs dB (20Hz – 20kHz)
Channel Separation 117 / 124 / 118 dB at 16Hz / 1kHz / 20kHz
THD+N 0.03 @ 1kHz @ 0dBFS
Channel Balance 0.09 @ 1kHz @ 0dBFS
Channel Phase 0.04 / 0.03 / 0.11 degrees at 16Hz / 1kHz / 20kHz
Group Delay 180 / 5.62 degrees (1–20kHz / 20–1kHz)
Signal-to-Noise Ratio (No Pre-emph) 99dB / 102dB dB (unweighted/weighted)
De-Emphasis Error 0.058 / 0.04 / 0.009 at 1kHz / 4kHz / 16kHz
Linearity Error @ –60.00dB / –70.00dB 0.16 / 0.17 dB (Test Signal Not Dithered)
Linearity Error @ –80.59dB / –85.24dB 0.23 / 0.25 dB (Test Signal Not Dithered)
Linearity Error @ –89.46dB / –91.24dB 0.26 / 0.28 dB (Test Signal Not Dithered)
Linearity Error @ –80.70dB / –90.31dB 0.12 / 0.15 dB (Test Signal Dithered)
Power Consumption Not Applicable / 11.3 watts (Standby / Operating)
Mains Voltage During Testing 235 – 246 (Minimum – Maximum)of 124dB at 1kHz, 117dB at 16Hz, and 118dB
at 20kHz. Apart from being excellent results,
these results are far better than would ever be
required to give maximal channel separation
and ideal stereo imaging. Channel phase
errors were also very low, with a ‘worst-case’
result of just 0.11° at 20kHz. Group delay was
typical for an ‘off-the-shelf’ delta-sigma DAC.
You can see from the tabulated figures that
Yamaha has gone to the trouble of imple-
menting the de-emphasis circuit that’s fitted
to the DAC (but often not used by manufac-
turers, due to the added cost of the support
circuitry), which means that the CD-S300 will
correctly add de-emphasis to pre-emphasized
CDs. There can’t be too many of these CDs
around, as manufacturers stopped this prac-
tice in around 1989, but if you have super-old
CDs in your library, you can be assured that
they’ll play back correctly... particularly since
the de-emphasis circuitry that is fitted to the
Yamaha CD-S300 is so precise, not least at
20kHz, where Newport Test Labs measured an
error of a minuscule 0.009dB.
Linearity error was a little below average,
particularly at very low recorded levels, but
these errors would not be audible when
listening to music.
Distortion at 0dB is shown in Graph 1 and
you can see that there’s a second harmon-
ic at –100dB (0.001% THD) and a third at
–95dB (0.0017%). Other harmonically-related
distortion components are also visible, but
they’re all down around –120dB (0.0001%)
and would be inaudible. The overall noise
floor is very low, as you can see, mostly more
than 130dB down, but the noise floor rises at
very low frequencies (extreme left of graph),
which is probably due to some mains-fre-
quency hum (50Hz) and components, andmore than likely responsible for the only av-
erage tabulated overall signal-to-noise ratios
measured by Newport Test Labs of
99dB unweighted and 102dB A-weighted.
Distortion at –20dB recorded level is
shown in Graph 3 and the distortion is
not only a little higher than I might have
expected, but also exclusively comprised of
odd-order harmonics and converter artefacts.
However all the components are sufficiently
low in level that they would not be audible,
even if you play your music at extreme-
ly high volume levels. The highest of the
components visible on the graph is the third
harmonic, and this is positioned at a level of
–108dB, or just 0.0003% THD.
At a recorded level of –60dB, distortion
increases again, related to recorded level,
and is again exclusively odd-order. This time
granulation noise becomes quite prominent,
as it usually does at such low levels. Again,
however, the highest (third harmonic) distor-
tion component is at –101dB (0.0008%), the
other components are down around –110dB
(0.0003%) and the granulation noise is down
at around –130dB.
Down at a recorded level of –90/91dB
(Graphs 5 and 6), the undithered signal
(Graph 5) shows typical converter errors, but
even when the signal is dithered, there’s a
significant second harmonic component re-
maining in the output, which would suggest
an older DAC architecture.
Intermodulation distortion was low for
both tested types, with CCIF IMD shown in
Graph 8. You can see the unwanted regen-
erated difference signal at 1kHz is more
than 100dB down (0.001%), as are the two
sidebands at 18kHz and 21kHz. These are
good results.
The oscillograms showing the Yamaha
CD-S300’s response to a 1kHz square wave
test signal and an impulse exhibit the typical