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Onkyo DX-7355 Review (CD Player)

NTTY

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Hello Everyone,

This is a review and detailed measurements of the Onkyo DX-7355 CD Player and transport.

Onkyo DX-7355_001.jpg



Onkyo DX-7355 - Presentation

This entry level CD Player from Onkyo was released around 2007, nearly 20 years ago. I've already reviewed the Onkyo C-733, which was released two year before.
There some common elements between thee two players:
  • VLSC (Vector Linear Shaping Circuitry): This seems to be proprietary and refined analog filtering post DAC, see more from the post of @Scytales.
  • DAC Wolfson 24bits/192kHz: This time no mistakes from the brochure, I indeed fond a Wolfson 8716 DAC in the player :)
  • Sony KSS-213CL: as opposed to the KSS-213C which was used in many CD players, the CL version found its way into higher end players, including four Accuphase. I could not find reliable information about the differences between KSS-213C and KSS-213CL.
As you can see from the font face, we get a headphones out, which I always appreciate. Rest is basic and standard. The "Next/Previous" buttons also perform FFW/REW (pushing them longer).

The back shows the essential too:

Onkyo DX-7355_002.jpg


We get two digital outputs. which is cool. And its published specs were:

Onkyo DX-7355_007.jpg


Inside, it's pretty neat:

Onkyo DX-7355_003.jpg


Sorry, the close up of the main board is a little fuzzy:

Onkyo DX-7355_004.jpg


The headphones dedicated card:

Onkyo DX-7355_006.jpg


Laser head Sony KSS-213CL:

Onkyo DX-7355_005.jpg


When it comes to using the Onkyo, the fast drive is always a pleasure, like good old classic and legendary KSS magnetic heads.
The buttons on the front have an entry level touch and feel, but I guess you use them often.
I listened to it via the headphones out, with a Beyer DT-770Pro and I could not spot any obvious issue.

As you could see on the picture, mine got a rough life, it seems, with several scratches and bumps, so time has come to see how it measures after some 20 years of service.


Onkyo DX-7355 - Measurements (RCA out)

All measurements performed with a Cosmos E1AD (grade G) and the Cosmos Scaler (100kohms from unbalanced input) for analog outputs, and a Motu UltraLite Mk5 for digital.

I am now consistent with my specific measurements for CD Players, as I described them in the post “More than we hear”, and as I reported them for the Onkyo C-733 review. Over time, this will help comparing the devices I reviewed.

As per its specs, the Onkyo outputs 1.31dB less than its specs, that is 1.72Vrms, so when directly compared with another CD Player that output 2Vrms, it will not shine, unless the operator adjusts the level.. The two channels were well balanced with a small 0.05dB difference, which is very good. The unbalanced outputs are non-inverting.

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As usual, let's start with my standard 999.91Hz sine @0dBFS (without dither) from the Test CD (RCA out):

Onkyo DX-7355_999.91Hz_0dBFS.jpg


We get a little more distorsion than with the best, but that will be easily masked by music since it is primarily made of H2 and H3. We also have a 10dB more than usual random noise at very low frequency, which we can ignore (at -130dBr) especially in that area of low sensitivity of our ears.

Let's have a look of the same at a lower level, and that is -6dBFS:

Onkyo DX-7355_999.91Hz_-6dBFS.jpg


The distortion has very much decreased compared to full scale, which means the Wolfson DAC is less at ease with very high level test tones. The above is a very good for a CD Player.

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I think you saw the total absence of power supply related spuriae (from 999.91Hz @0dBFS test tone without dither):

Onkyo DX-7355_PS.jpg


We can't find the 50Hz (Europe) nor its harmonics. This linear scale shows that the little higher than usual low level noise from 20Hz to 100Hz is negligible. All of this is very good so far.

----

Next is the bandwidth:

Onkyo DX-7355_BW.jpg


You see the channel imbalance of 0.05dB. This view is very zoomed and so the trace is near flat, with only a +0.1dB deviation.

And now let's have a look at the job of the oversampling filter:

Onkyo DX-7355_OS.jpg


This a good -80dB minimum of attenuation, out of audio-band. No noise shaping can be seen, even up to 80kHz like shown above, so that is nice (I think). The VLSC specific analog filtering might be the reason why we get good results here. Thanks again to @Scytales for more insights on the matter.
The digital filter is fully active at 24kHz, so that's good too.

----

Let's have a look at the multitone test that a lot of you like very much:

Onkyo DX-7355_MT.jpg


We see an increase of low level noise at higher frequencies, but this player guarantees from 16.5bits to 18bits music reproduction free of distortion.

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Let's move on to the jitter test:

Onkyo DX-7355_JTest.jpg


Nailed! The red trace is from the digital output of the Onkyo, and the blue one from analog RCA.
It's difficult to do better than that, but there are two very low lateral bands at -118dBr, so I have so I have something to show but you won't have anything to hear :)

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Started with the Teac VRDS-20 review, and on your request + support to get it done (more here), I'm adding now an "intersample-overs" test which intends to identify the behavior of the digital filtering and DAC when it come to process near clipping signals. Because of the oversampling, there might be interpolated data that go above 0dBFS and would saturate (clip) the DAC and therefore the output. And this effect shows through distorsion (THD+N measurement up to 96kHz):

Intersample-overs tests
Bandwidth of the THD+N measurements is 20Hz - 96kHz
5512.5 Hz sine,
Peak = +0.69dBFS
7350 Hz sine,
Peak = +1.25dBFS
11025 Hz sine,
Peak = +3.0dBFS
Teac VRDS-20-30.7dB-26.6dB-17.6dB
Yamaha CD-1-84.6dB-84.9dB-78.1dB
Denon DCD-900NE-34.2dB-27.1dB-19.1dB
Denon DCD-SA1-33.6dB-27.6dB-18.3dB
Onkyo C-733-88.3dB-40.4dB-21.2dB
Denon DCD-3560-30.2dB-24.7dB-17.4dB
Myryad Z210-70.6dB (noise dominated)-71.1dB (noise dominated)-29.4dB (H3 dominated)
Sony CDP-x333ES-30.5dB-24.8dB-16.3dB
BARCO-EMT 982-32.7dB-24.5dB-16.3dB
Onkyo DX-7355-82.4dB-80.4dB-30.7dB

I kept some references and will keep the same for other reviews, so you can quickly compare. The results of the Onkyo DX-7355 mean that it has 2dB of headroom in its oversampling filter, and that is very good news, I think. This CD Player will resist very well those too hot masters which are way too common.

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Let's continue with the good old 3DC measurement that Stereophile was often using as a proof of low noise DAC. It is from an undithered 997Hz sine at -90.31dBFS. With 16bits, the signal should appear (on a scope) as the 3DC levels of the smallest symmetrical sign magnitude digital signal:

Onkyo DX-7355_3DC_RCA.jpg


This is a very good trace for an entre level CD Player, which means it offers a very good resolution, and this time much better than the Sony CDP-X333ES.
At this lowest symmetrical level in 16bits PCM, we expect to see a square only, as it is no longer possible to represent a sine. The ringing is due to the Gibbs Phenomenon and the reconstruction filter which is symmetrical, impulse response below (for once):

1751302341164.png


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Other measurements (not shown):
  • IMD AES-17 DFD "Analog" (18kHz & 20kHz 1:1) : -90.4dB
  • IMD AES-17 DFD "Digital" (17'987Hz & 19'997Hz 1:1) : -81.4dB
  • IMD AES-17 MD (41Hz & 7993Hz 4:1): -81dB
  • IMD CCIF (19kHz & 20kHz 1:1) : -81.4dB
  • IMD DIN (250Hz & 8kHz 4:1) : -76.9dB
  • IMD SMPTE (60Hz & 7kHz 1:4) : -77.7dB
  • IMD TDFD Bass (41Hz & 89Hz 1:1) : -118.3dB
  • IMD TDFD (13'58Hz & 19841Hz 1:1) : -98.1dB
  • Dynamic Range : 97.6dB (without dither @-60dBFS)
  • Crosstalk: -106dBr (100Hz), -103dBr (1khz), -79dBr (10kHz)
  • Pitch Error : 19'997.03Hz (19'997Hz requested) ie 1.5ppm
  • Gapless playback : Yes
I now added a gapless playback test, on your request.

Some of the results above are below what I usually measure, even though not a concern, but we already saw some of that with the multitone test, so not a big surprise to get a little more distortion than usual with IMD tests involving high frequency test tones. Note all the above are from the left channel which was a few dB more distortion than the right one, so you get the worst case scenario.

The clock is very precise with a very small 1.5ppm deviation. This is very good and I'd like to see such a result more often, even if not really useful (even at 70ppm, our ears would be more than happy).

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Last and not least, I like to run a THD vs Frequency sweep at -12dBFS as it shows how the conversion has evolved over time. I am currently using the beta version of REW and I discovered that this sweep gives better and more reliable results than before. I overlaid the results of the two channels with one from the Onkyo DX-7355 and one channel of the Onyko C-733 that I often like to use as an exemple:

Onkyo DX-7355_THDvsFreq.jpg


Very good results of the Onkyo DX-7355 here. The right channel performs a little better than the left one, which concurs with what I saw with all other tests.


Onkyo DX-7355 - Measurements (Digital Coax Out)

I've seen several of you reviewing CD players using their digital outputs, in case the results could be improved from an external DAC.

So let's go with the 999.91Hz @0dBFS:

Onkyo DX-7355_999.91Hz_0dBFS_Coax.jpg


This is as good as it gets from digital output. The 3DC level test (997Hz @0dBFS) shows no modification either:

Onkyo DX-7355_3DC_Coax.jpg


But I think that from now on, I will just use the intersample overs test at 5512.50Hz, with a phase shift of 67.5°, like I did for the TASCAM CD-200 review. This signal generates an overshoot of +0.69dB and so if the signal would be modified before being sent, it would show either a reduction of amplitude or we'd see some sort of saturation. So here we go, the below is a comparison between the WAV File directly processed by the PC, and when played by the Onkyo via the coax out:

Onkyo DX-7355_ISO_Coax_vs_WAV.jpg


The two traces are the same, and we get the same "over" of +0.69dBFS. To me, this is as close as "bit perfect" digital output as we can get.


Onkyo DX-7355 - Testing the drive

What would be good measurements if the drive would not properly read a slightly scratched CD, or one that was created at the limits of the norm? The below tests reply to these questions.

Test typeTechnical testResults
Variation of linear cutting velocityFrom 1.20m/s to 1.40m/sPass
Variation of track pitchFrom 1.5µm to 1.7µmPass
Combined variations of track pitch and velocityFrom 1.20m/s & 1.5µm to 1.40m/s & 1.7µmPass
HF detection (asymmetry pitch/flat ratio)Variation from 2% to 18%Pass
Dropouts resistanceFrom 0.05mm (0.038ms) to 4mm (3.080ms)Up to 1.25mm.
Combined dropouts and smallest pitchFrom 1.5µm & 1mm to 1.5µm & 2.4mmUp to 1mm.
Successive dropoutsFrom 2x0.1mm to 2x3mmUp to 1.5mm.

The drive was able to consistently continue playing, without generating typical digital clicks, with dropouts of up to 1.25mm. The interpolation could be heard as soon as it kicked in. That said, the Onkyo never stopped playing, even with 4mm dropouts, but is was skipping few seconds of the track and exhibited massive clock deviation.
The Onkyo had no issue with variable linear velocity and/or track pitch, as well as with HF detection.
These results are in par with many other KSS laser heads I tested, but below the Onkyo C-733 which uses the same KSS-213CL, maybe because of a better servo control?


Conclusion

You now know much more about this player which can be found used for very little money. And it is not only a very good CD Player, but also a "perfect" transport.

Be careful when comparing it with another player, the lower output voltage might give you the feeling it's less performing, so adjust the volume accordingly and it will sound great. The good resistance to intersample-overs (>2dB) is good news, something to appreciate because not common, I think.

With a modern DAC, it will perform better, should you be able to hear a difference.

I hope you enjoyed this review!
 
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Great review, and it confirms my experience with this fantastic player. It was long considered an exceptional player and was also a popular tuning object among commercial tuners.

I use it together with the Cambridge CXC as a player and transport. I can confirm that it benefits from a good DAC; in my case, it's a 31-year-old Cambridge Dacmagic 1.
 
Thanks a lot for another great test @NTTY !!

The graph of the 3DC level test at the end is either misslabeled as from the Onkyo C-733 or is actually the one from the C-733?

Looks like Onkyo has produced some great CDPs!
 
Oops, mislabeled indeed. I’ll correct that but since I did not keep the original measurements, I’ll have to do it again

I think Onkyo did great players indeed. I’m eager to test more!
 
It's nice to know that this Onkyo model reads a disc quickly, the newer one's take about 10-12 seconds. (TOC)
 
  • VSLC (Vector Linear Shaping Circuitry): This is proprietary noise shaping which was featured on a number of CD Players from Onkyo, kind of the Alpha filtering from Denon.
Thank you for another great review!

As for the feature named VLSC by Onkyo, I doubt it's a digital process. The explanation from Onkyo is very evasive:

Onkyo_DX7355_VLSC.png

This VLSC is obviously illustrated as an analogue circuit.

Moreover, this acronym is mentioned by Onkyo in a patent describing a kind of analogue low-pass filter (see column 1, lines 13 to 29 of the description).

I was not able to find the service manual of the DX-7355, but the one of the DX-7555 which, I suspect, is a somewhat similar higher end model than the DX-7355. It shows the following circuit, where the portion circled in red must correspond to the VLSC. It appears to be a simplified implementation of the general circuit idea described in the above-mentioned patent:

Onkyo_DX7555_VLSC.png


Through simulation, this circuit works well as a low pass-filter, with better HF attenuation than some simpler recommended circuits straight out of the datasheet of some DAC chips such as the AK4493 or CS4392. An out of band resonance might manifest itself depending on the value of C4017 (not disclosed), but with 910 pF or more, I have found that the frequency response above 20 kHz begins to become reasonably flat, with a cut-off frequency of about 40 kHz.

Perhaps other members will provide more insightful comments, but this VLSC seems to be a fancy name for an analogue low-pass filter design with better than average out-of-band attenuation.
 
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Any observations on disc reading noise?
None At least I just don’t remember it making any noise. And I spent many hours with it running at 50cm from my hears (when performing measurements). Maybe I could add a standardized measurement of that. I’ll think about it.
 
Thank you for another great review!

As for the feature named VLSC by Onkyo, I doubt it's a digital process. (…)
Interesting, thanks! I probably read too quickly the description :)
 
think Onkyo did great players indeed. I’m eager to test more!
Yeah, more Onkyo would be great!

As I said, I would love to see a review of the compact C-721 that I inherited from my parents, and looking so similar to your reference C-733, nudge, nudge! ;)

 
Yeah, more Onkyo would be great!

As I said, I would love to see a review of the compact C-721 that I inherited from my parents, and looking so similar to your reference C-733, nudge, nudge! ;)
That's a much older one with early 1bit from NPC (only 16bits data input) with an included 4th order noise shaper and relatively low performing digital filter, but that would be interesting to test anyways! I'd be curious to see the difference with the Philips 1bit offering (TDA1547 + SAA7350) of the same period.
 
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