This is a review and detailed measurements of the Yamaha CDX-393 (MKI) CD stereo player.
By the looks of it, you can guess this is one more old CD player, and you're right, it's from 1999.
My first review of the Onkyo C-733 here contains information about my measurements which I align with the AES standard (to few exceptions). It means that, over time, you can compare the devices I reviewed.
Yamaha CDX-393 - Presentation
Released in 1999, it was a low cost CD player (I think below 200$) featuring the minimum
Back panel shows only RCA outputs:
The MKII version of the same player offered a coax output, at least. So it's a very basic player and I only have to mention the below:
Let's have a quick look at the inside before going to measurements:
The Panasonic DAC is below the card, so we don't see it here.
As with many older players, it's really fast to skip tracks back and forth. Jumping 30 tracks on my test CD is nearly instantaneous, and I love it. It's not as fast as a KKS-151 or KSS-190, but really close.
Yamaha CDX-393 Measurements
From now on, I will be consistent with my measurements as I described them in the post “More than we hear”, and as I reported them in the below review. Over time, this will help comparing the devices I reviewed.
The Yamaha CDX-393 outputs 2.111Vrsm, and there was a channel imbalance of around 0.12dB which is good. The analog output respects polarity.
Here you go with my standard 999.91Hz sine @0dBFS (undithered) from the test CD (RCA out):
Left and Right channels are shown and are nearly identical. THD sits at -97dB and so will clear CD Audio content.
The Yamaha suffers from low level noise preventing the ENOB to reach 16bits.
I think you spotted the deviation from 999.91Hz, as the software sees 999.84Hz. This is a clock issue, even after the upgrade (see later in this thread). Indeed I updated the ceramic resonator by a Xtal but got the associated capacitor wrong, hence a 70ppm precision "only", but still decent for audio.
Let's continue with the same 999.91Hz (still undithered) but @-6dBFS:
THD improves with the lower signal as well as noise floor. Obviously this DAC is not so happy playing at 0dBFS. This is a good performance.
I also add the below which is a new measurement with shaped dither added to the signal and compared to no dither:
This test is useful to know if the internal has a higher resolution than 16bits, even if we are using 16bits PCM files. Indeed, with shaped dither, it is possible to lower the noise floor up to 5kHz. But in the case of the CDX-393 this technique did not generate any improvements. So 16bits max resolution we have.
You probably previously saw a small and negligible power supply leakage (50Hz and 100Hz), but let's zoom:
This actually better than the Teac VRDS-20, eat this big boy
Bandwidth is flat:
We see some ripple, this is unusual and surprising for an 8x oversampling filter. Probably some cost savings had to be achieved. And let's have a deeper look at the filtering behavior with the below overlay of white noise and AES IMD test (18kHz + 20kHz):
So yes, the filter is slow and has a worst case attenuation of -50dB, which is weak. In 1982, the Marantz CD-73 was already doing better.
On that view, we see a slow increase of noise floor beyond 20kHz indicating arelatively agressive noise shaping in action in this DAC.
Multitone (1/10 decade) showed a happy CD player, not having issue to achieve 16bits+ free of distortion:
Let's go with the Jitter test to see if the clock issue shows here:
The red trace is what is recorded on the test CD (taken from the digital output of Onkyo C-733, since this Yamaha does not have one).
Well, I thought it'd be worse than that. We see side bands indeed, but not really of concerns. After all, there might be a deviation but it could be a fixed one on this test. I'll wait for your comments and expertise. There are two resonators in this player, one for the DAC (VJ719800 16.9344MHz) and one for the micro-controller (VJ677200 4.19MHz).
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):
I kept some references and will keep the same for other reviews, so you can quickly compare. The results of the Yamaha CDX-393 mean the oversampling filter has mo headroom. The Yamaha CD-1 shines here because it's old enough not to have an oversampling filter.
Here are other standard measurements:
The results are very good, as I've put the Onkyo C-733 for reference which is near best in class on that measurement. The Yamaha CDX-393 is let down, on more time, by its noise level, which I attribute to the noise shaping conversion technique that I've seen in wider bandwidth analysis.
And since I don't have measurements to show about the digital outputs (because there are none), let me add the below one more to show the noise shaper behavior:
We see the shape to reject quantization noise outside audio band. I do not see that with other DAC as this normally happens below the 16bits resolution. Here it comes to disrupt audio band too, and by 2dB on top of the dither noise of my test CD. I suppose this is where this DAC shows its limitations (as with the oversampling filter), but I doubt this can be heard.
Yamaha CDX-393 - 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.
The drive was able to consistently continue playing, without generating typical digital clicks, with dropouts of up to 4mm (the maximum I can test!). The interpolation effect remained hidden to my ears when it kicked-off (at 2mm dropouts) and succeeded to maintain a constant flow up to 4mm dropouts. The Yamaha had no issue with variable linear velocity and/or track pitch, as well as with HF detection.
Obviously nothing can prevent this drive from reading an audio CD. I guess I could drill a hole into the silver disc and the Yam' would be happy with it. This is to date the best drive I tested!
Conclusion
Thank you if you made it to that point!
To be honest, outside the frequency deviations, these are good performances for a really cheap player of 25 years ago! And I find it amusing to be faced with some sort of frequency wobble, it reminds me of good old times
I'm tempted to replace the resonators (EDIT: done see later in this thread), to see if I can fix the issue, and maybe that would improve all other measurements?
This is good to remember that old players can face issues. Maybe the resonators have aged and that could be the reason. Buying an older player comes with risks. I think it's good to be reminded of that, especially when I see older gears sold at very high price without having been serviced (and of course no measurements to validate their good health).
Last and not least, the drive of this player offers a best in class resistance to scratched and not so well pressed/burnt CD, and this is invaluable.
I hope you enjoyed this review.
By the looks of it, you can guess this is one more old CD player, and you're right, it's from 1999.
My first review of the Onkyo C-733 here contains information about my measurements which I align with the AES standard (to few exceptions). It means that, over time, you can compare the devices I reviewed.
Yamaha CDX-393 - Presentation
Released in 1999, it was a low cost CD player (I think below 200$) featuring the minimum
Back panel shows only RCA outputs:The MKII version of the same player offered a coax output, at least. So it's a very basic player and I only have to mention the below:
- Conversion is from Panasonic, the MN66271RA, and I did test this one yet, reason for my interest.
- Laser head is from Sony, the KSS-213C.
Let's have a quick look at the inside before going to measurements:
The Panasonic DAC is below the card, so we don't see it here.
As with many older players, it's really fast to skip tracks back and forth. Jumping 30 tracks on my test CD is nearly instantaneous, and I love it. It's not as fast as a KKS-151 or KSS-190, but really close.
Yamaha CDX-393 Measurements
From now on, I will be consistent with my measurements as I described them in the post “More than we hear”, and as I reported them in the below review. Over time, this will help comparing the devices I reviewed.
The Yamaha CDX-393 outputs 2.111Vrsm, and there was a channel imbalance of around 0.12dB which is good. The analog output respects polarity.
Here you go with my standard 999.91Hz sine @0dBFS (undithered) from the test CD (RCA out):
Left and Right channels are shown and are nearly identical. THD sits at -97dB and so will clear CD Audio content.
The Yamaha suffers from low level noise preventing the ENOB to reach 16bits.
I think you spotted the deviation from 999.91Hz, as the software sees 999.84Hz. This is a clock issue, even after the upgrade (see later in this thread). Indeed I updated the ceramic resonator by a Xtal but got the associated capacitor wrong, hence a 70ppm precision "only", but still decent for audio.
Let's continue with the same 999.91Hz (still undithered) but @-6dBFS:
THD improves with the lower signal as well as noise floor. Obviously this DAC is not so happy playing at 0dBFS. This is a good performance.
I also add the below which is a new measurement with shaped dither added to the signal and compared to no dither:
This test is useful to know if the internal has a higher resolution than 16bits, even if we are using 16bits PCM files. Indeed, with shaped dither, it is possible to lower the noise floor up to 5kHz. But in the case of the CDX-393 this technique did not generate any improvements. So 16bits max resolution we have.
You probably previously saw a small and negligible power supply leakage (50Hz and 100Hz), but let's zoom:
This actually better than the Teac VRDS-20, eat this big boy
Bandwidth is flat:
We see some ripple, this is unusual and surprising for an 8x oversampling filter. Probably some cost savings had to be achieved. And let's have a deeper look at the filtering behavior with the below overlay of white noise and AES IMD test (18kHz + 20kHz):
So yes, the filter is slow and has a worst case attenuation of -50dB, which is weak. In 1982, the Marantz CD-73 was already doing better.
On that view, we see a slow increase of noise floor beyond 20kHz indicating a
Multitone (1/10 decade) showed a happy CD player, not having issue to achieve 16bits+ free of distortion:
Let's go with the Jitter test to see if the clock issue shows here:
The red trace is what is recorded on the test CD (taken from the digital output of Onkyo C-733, since this Yamaha does not have one).
Well, I thought it'd be worse than that. We see side bands indeed, but not really of concerns. After all, there might be a deviation but it could be a fixed one on this test. I'll wait for your comments and expertise. There are two resonators in this player, one for the DAC (VJ719800 16.9344MHz) and one for the micro-controller (VJ677200 4.19MHz).
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 (Non-Oversampling CD Player) | -79.6dB | -35.3dB | -78.1dB |
| Yamaha CDX-393 | -32.8dB | -27.6dB | -18.3dB |
| Onkyo C-733 | -79.8dB | -29.4dB | -21.2dB |
I kept some references and will keep the same for other reviews, so you can quickly compare. The results of the Yamaha CDX-393 mean the oversampling filter has mo headroom. The Yamaha CD-1 shines here because it's old enough not to have an oversampling filter.
Here are other standard measurements:
- Crosstalk : -114dB (@1kHz)
- IMD AES : -85.6dB (18kHz + 20kHz 1:1 @-5dBFS)
The results are very good, as I've put the Onkyo C-733 for reference which is near best in class on that measurement. The Yamaha CDX-393 is let down, on more time, by its noise level, which I attribute to the noise shaping conversion technique that I've seen in wider bandwidth analysis.
And since I don't have measurements to show about the digital outputs (because there are none), let me add the below one more to show the noise shaper behavior:
We see the shape to reject quantization noise outside audio band. I do not see that with other DAC as this normally happens below the 16bits resolution. Here it comes to disrupt audio band too, and by 2dB on top of the dither noise of my test CD. I suppose this is where this DAC shows its limitations (as with the oversampling filter), but I doubt this can be heard.
Yamaha CDX-393 - 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 type | Technical test | Results |
| Variation of linear cutting velocity | From 1.20m/s to 1.40m/s | Pass |
| Variation of track pitch | From 1.5µm to 1.7µm | Pass |
| Combined variations of track pitch and velocity | From 1.20m/s & 1.5µm to 1.40m/s & 1.7µm | Pass |
| HF detection (asymmetry pitch/flat ratio) | Variation from 2% to 18% | Pass |
| Dropouts resistance | From 0.05mm (0.038ms) to 4mm (3.080ms) | Pass |
| Combined dropouts and smallest pitch | From 1.5µm & 1mm to 1.5µm & 2.4mm | Pass |
| Successive dropouts | From 2x0.1mm to 2x3mm | Pass |
The drive was able to consistently continue playing, without generating typical digital clicks, with dropouts of up to 4mm (the maximum I can test!). The interpolation effect remained hidden to my ears when it kicked-off (at 2mm dropouts) and succeeded to maintain a constant flow up to 4mm dropouts. The Yamaha had no issue with variable linear velocity and/or track pitch, as well as with HF detection.
Obviously nothing can prevent this drive from reading an audio CD. I guess I could drill a hole into the silver disc and the Yam' would be happy with it. This is to date the best drive I tested!
Conclusion
Thank you if you made it to that point!
To be honest, outside the frequency deviations, these are good performances for a really cheap player of 25 years ago! And I find it amusing to be faced with some sort of frequency wobble, it reminds me of good old times
I'm tempted to replace the resonators (EDIT: done see later in this thread), to see if I can fix the issue, and maybe that would improve all other measurements?
This is good to remember that old players can face issues. Maybe the resonators have aged and that could be the reason. Buying an older player comes with risks. I think it's good to be reminded of that, especially when I see older gears sold at very high price without having been serviced (and of course no measurements to validate their good health).
Last and not least, the drive of this player offers a best in class resistance to scratched and not so well pressed/burnt CD, and this is invaluable.
I hope you enjoyed this review.
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