Hello Everyone,
This is a review and detailed measurements of the Denon DCD-720AE CD player and Transport.
Denon DCD-720AE - Presentation
This player was available from 2012 to 2017 and was the second entry line model, above the 520AE. As you can see on the front face, it has a phones output, which is always nice and also a USB input. It will play MP3 and WMA files.
It features the now famous "Alpha" oversampling filter from Denon, in a 32bits version. The buttons have a luxury touch, I liked that.
The back shows the standard RCA outputs, together with one optical SPDIF output:
This is the inside:
Power supply on the left and filtering in the back, drive in the middle, with the servo/decoding board on the right. The conversion board is that small card on the top right of the player:
And it is written on it, the DCD-520AE receives a BurrBrown(TI) PCM5102 and the DCD-720AE gets the PCM5142. This latter chip offers a miniDSP, which is probably used by Denon for the Alpha filtering.
This player is pleasant to use, and if the drive is not as fast as old ones, it's very close. The buttons on the front face
Denon DCD-720AE - Measurements (Analog out)
All measurements performed with a Cosmos E1AD (grade G) and the Cosmos Scaler (100kohms from unbalanced input).
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.
The Denon output 0.39dB less than the standard 2Vrsm form the fixed RCA outputs, that is 1.91Vrms. The channel imbalance was of 0.14dB. The single-ended outputs are non-inverting.
----
As usual, let's start with my standard 999.91Hz sine @0dBFS (without dither) from the Test CD (RCA out):
This is the left channel only, the right is identical. The ENOB is limited by the THD, which in "only" -91.5dB.
Let's see if things get better at -6dBFS:
Yes, the distorsion went down, the Denon does not like playing full scale tones. From the above view, we get very close to the full resolution of CD Audio, so that's good.
I think you already spotted power supply spuriae:
We see here leakage at 50Hz (Europe) and multiple harmonics. But they are low enough not to be a concern.
----
Next in the list is the bandwidth:
This is flat, and you can see ringing at the upper range, which is what I usually get from very old CD players, not modern ones. So let's have a look at that beyond the audio range.
And voilà, this is a low performer. The out of audio band attenuation is only 60dB, and we see the ringing, from 24kHz. In this overlay with the AES-IMD 18kHz+20kHz test tones, we see that their artifacts (mirror copy at 24.1kHz and 26.1kHz) are attenuated by only 60dB. That said, and as opposed to other Denon players, this AL32 filtering does not cheat on that test. The attenuation of the AES-IMD test corresponds to the filter's behavior with white noise, that means no selective filtering here. You can also see that the subsequent artifacts (copies of 18kHz & 20kHz) of the conversion are poorly attenuated too
----
Let's have a look at the multitone test that a lot of you like very much:
This is a good trace, you can ignore the few spikes. We get more that 18bits free of distorsion.
----
Let's move on to the jitter test:
Besides the higher than usual noise floor, we see two side bands, far from the fundamental but low enough to of no concern.
----
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 Denon DCD-720AE mean that it has nearly no headroom in its oversampling filter.
----
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:
Ah! This is interesting. It is a relatively good sine that we see, and that is only possible if there is an increase of the bit-depth through intelligent processing. This is what the early versions of the ALPHA filtering of Denon were doing. This processing might partially explain some of the low level noise I spotted here and there.
In the past, Denon was advertising this as an increase of the resolution beyond 16bits, and yes it is, but the original digital signal must be modified to get there. It is useful to shine on that specific test, but beyond that, I'm not sure. That said, as we can see, this means small level signals get better resolved through this processing. But with modern masters done with (shape) dither, this advantage is somewhat cancelled.
----
Other measurements (not shown):
The pitch error test shows a precise clock with only 9.5ppm deviation.
----
You might know that it is now possible to go below the theoretical resolution of 16bits of the CD Audio, using a technique that is called noise shaping. This a mathematical process to reduce the quantization errors due to the format (only 16bits) and spread these errors in a smart manner so the actual resolution can be increased where it matters for our ears.
Like I recently did in the review of the Sony CDP-X333ES, the below is an FFT of the same 999.91Hz Sine test tone at full scale (0dBFS), with shape dither. To process and calculate what the player is capable in terms of resolution, I reduce the span to 20Hz - 6000Hz, instead of the standard 20Hz - 20kHz, to prevent adding the noise generated at the higher frequencies. I added the result with the Denon DCD-900NE as a reference:
From that direct comparison, we can see that the Denon DCD-720AE does not like playing 0dBFS test tones, as the noise floor is higher than the one of the Denon DCD-900NE. ENOB is dominated by the distorsion, at 26db more than with the Denon DCD-900NE.
Lowering the test tone at -6dBFS helps the DCD-720AE to distord less and so I could compute 16.6bits of resolution, the limit being the Noise in that case.
----
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. The below is an overlay of the left and right channels of the Denon DCD-720AE with one channel of the more recent Denon DCD-900NE:
This result is still good, but shows 20dB more distorsion than the "best is class" Denon DCD-900NE.
Denon DCD-720AE - Measurements (Optical Out)
Many of you like to know how a CD player behaves from its digital outputs.
The little imprecision of the clock (9.5ppm) forced me to reduce the number of averages I usually performe to only 4, because my digital interface does not re-clock the incoming data. Here is the 999.91Hz sine @0dBFS (without dither):
This is what is on the WAV, as far as I can tell.
Since I had a doubt about potential processing, so I used the 3DC levels test file (997Hz @-9031dBFS) which much show the smallest 16bits symmetrical signed signal:
Yes, no issue here, he get the 3 basic levels, forming a square wave at this min level.
By the way, and I think I'll run that test more often, I connected the Denon to the SMLS PS200 DAC, and did some measurements. I give you two. The first one is the standard 999.91Hz @0dBFS without dither:
As usual with the SMSL, this is very close to the WAV file. So let's try with shape dither:
The THD+N calculation is limited to 6kHz in that view so we can see the true achievable resolution, and that is 18.5bits with the SMSL.
All of that means the digital output of the Denon is "perfect".
Denon DCD-720AE - 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 2.5mm. It continued to play, while generating clicks with the max dropouts of 3mm and failed (stopped playing) with 4mm dropouts. The Denon had no issue with variable linear velocity and/or track pitch, as well as with HF detection. These results are very good, and to be appreciated
Conclusion
The Denon DCD-720AE does not like high level signals, and has a little more distorsion than what I see with many other CD players, from its analog outputs.
The touch and feel, a stable clock, a fast drive that can read heavily scratched CDs, and a "perfect" optical output make this player the ideal companion of an external DAC, for best in class Audio CD experience. The CDA has still a lot of pleasure to deliver to you, and this is a very nice drive.
Enjoy your day!
This is a review and detailed measurements of the Denon DCD-720AE CD player and Transport.
Denon DCD-720AE - Presentation
This player was available from 2012 to 2017 and was the second entry line model, above the 520AE. As you can see on the front face, it has a phones output, which is always nice and also a USB input. It will play MP3 and WMA files.
It features the now famous "Alpha" oversampling filter from Denon, in a 32bits version. The buttons have a luxury touch, I liked that.
The back shows the standard RCA outputs, together with one optical SPDIF output:
This is the inside:
Power supply on the left and filtering in the back, drive in the middle, with the servo/decoding board on the right. The conversion board is that small card on the top right of the player:
And it is written on it, the DCD-520AE receives a BurrBrown(TI) PCM5102 and the DCD-720AE gets the PCM5142. This latter chip offers a miniDSP, which is probably used by Denon for the Alpha filtering.
This player is pleasant to use, and if the drive is not as fast as old ones, it's very close. The buttons on the front face
Denon DCD-720AE - Measurements (Analog out)
All measurements performed with a Cosmos E1AD (grade G) and the Cosmos Scaler (100kohms from unbalanced input).
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.
The Denon output 0.39dB less than the standard 2Vrsm form the fixed RCA outputs, that is 1.91Vrms. The channel imbalance was of 0.14dB. The single-ended outputs are non-inverting.
----
As usual, let's start with my standard 999.91Hz sine @0dBFS (without dither) from the Test CD (RCA out):
This is the left channel only, the right is identical. The ENOB is limited by the THD, which in "only" -91.5dB.
Let's see if things get better at -6dBFS:
Yes, the distorsion went down, the Denon does not like playing full scale tones. From the above view, we get very close to the full resolution of CD Audio, so that's good.
I think you already spotted power supply spuriae:
We see here leakage at 50Hz (Europe) and multiple harmonics. But they are low enough not to be a concern.
----
Next in the list is the bandwidth:
This is flat, and you can see ringing at the upper range, which is what I usually get from very old CD players, not modern ones. So let's have a look at that beyond the audio range.
And voilà, this is a low performer. The out of audio band attenuation is only 60dB, and we see the ringing, from 24kHz. In this overlay with the AES-IMD 18kHz+20kHz test tones, we see that their artifacts (mirror copy at 24.1kHz and 26.1kHz) are attenuated by only 60dB. That said, and as opposed to other Denon players, this AL32 filtering does not cheat on that test. The attenuation of the AES-IMD test corresponds to the filter's behavior with white noise, that means no selective filtering here. You can also see that the subsequent artifacts (copies of 18kHz & 20kHz) of the conversion are poorly attenuated too
----
Let's have a look at the multitone test that a lot of you like very much:
This is a good trace, you can ignore the few spikes. We get more that 18bits free of distorsion.
----
Let's move on to the jitter test:
Besides the higher than usual noise floor, we see two side bands, far from the fundamental but low enough to of no concern.
----
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) |
| Denon DCD-720AE | -44.1dB | -29.6dB | -19.2dB |
I kept some references and will keep the same for other reviews, so you can quickly compare. The results of the Denon DCD-720AE mean that it has nearly no headroom in its oversampling filter.
----
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:
Ah! This is interesting. It is a relatively good sine that we see, and that is only possible if there is an increase of the bit-depth through intelligent processing. This is what the early versions of the ALPHA filtering of Denon were doing. This processing might partially explain some of the low level noise I spotted here and there.
In the past, Denon was advertising this as an increase of the resolution beyond 16bits, and yes it is, but the original digital signal must be modified to get there. It is useful to shine on that specific test, but beyond that, I'm not sure. That said, as we can see, this means small level signals get better resolved through this processing. But with modern masters done with (shape) dither, this advantage is somewhat cancelled.
----
Other measurements (not shown):
- IMD AES-17 DFD "Analog" (18kHz & 20kHz 1:1) : -69.9dB
- IMD AES-17 DFD "Digital" (17'987Hz & 19'997Hz 1:1) : -72.7dB
- IMD AES-17 MD (41Hz & 7993Hz 4:1): -84.2dB
- IMD CCIF (19kHz & 20kHz 1:1) : -71.8dB
- IMD DIN (250Hz & 8kHz 4:1) : -78.5dB
- IMD SMPTE (60Hz & 7kHz 1:4) : -78.3dB
- IMD TDFD Bass (41Hz & 89Hz 1:1) : -98,2dB
- IMD TDFD (13'58Hz & 19841Hz 1:1) : -84.5dB
- Dynamic Range : 97.6dB (without dither @-60dBFS)
- Crosstalk: -115dBr (100Hz), -114dBr (1khz), -81dBr (10kHz)
- Pitch Error : 19'997.19Hz (19'997Hz requested) ie 9.5ppm
- Gapless playback : Yes
The pitch error test shows a precise clock with only 9.5ppm deviation.
----
You might know that it is now possible to go below the theoretical resolution of 16bits of the CD Audio, using a technique that is called noise shaping. This a mathematical process to reduce the quantization errors due to the format (only 16bits) and spread these errors in a smart manner so the actual resolution can be increased where it matters for our ears.
Like I recently did in the review of the Sony CDP-X333ES, the below is an FFT of the same 999.91Hz Sine test tone at full scale (0dBFS), with shape dither. To process and calculate what the player is capable in terms of resolution, I reduce the span to 20Hz - 6000Hz, instead of the standard 20Hz - 20kHz, to prevent adding the noise generated at the higher frequencies. I added the result with the Denon DCD-900NE as a reference:
From that direct comparison, we can see that the Denon DCD-720AE does not like playing 0dBFS test tones, as the noise floor is higher than the one of the Denon DCD-900NE. ENOB is dominated by the distorsion, at 26db more than with the Denon DCD-900NE.
Lowering the test tone at -6dBFS helps the DCD-720AE to distord less and so I could compute 16.6bits of resolution, the limit being the Noise in that case.
----
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. The below is an overlay of the left and right channels of the Denon DCD-720AE with one channel of the more recent Denon DCD-900NE:
This result is still good, but shows 20dB more distorsion than the "best is class" Denon DCD-900NE.
Denon DCD-720AE - Measurements (Optical Out)
Many of you like to know how a CD player behaves from its digital outputs.
The little imprecision of the clock (9.5ppm) forced me to reduce the number of averages I usually performe to only 4, because my digital interface does not re-clock the incoming data. Here is the 999.91Hz sine @0dBFS (without dither):
This is what is on the WAV, as far as I can tell.
Since I had a doubt about potential processing, so I used the 3DC levels test file (997Hz @-9031dBFS) which much show the smallest 16bits symmetrical signed signal:
Yes, no issue here, he get the 3 basic levels, forming a square wave at this min level.
By the way, and I think I'll run that test more often, I connected the Denon to the SMLS PS200 DAC, and did some measurements. I give you two. The first one is the standard 999.91Hz @0dBFS without dither:
As usual with the SMSL, this is very close to the WAV file. So let's try with shape dither:
The THD+N calculation is limited to 6kHz in that view so we can see the true achievable resolution, and that is 18.5bits with the SMSL.
All of that means the digital output of the Denon is "perfect".
Denon DCD-720AE - 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) | Up to 2.5mm. |
| Combined dropouts and smallest pitch | From 1.5µm & 1mm to 1.5µm & 2.4mm | 2.4mm. |
| Successive dropouts | From 2x0.1mm to 2x3mm | 2.4mm. |
The drive was able to consistently continue playing, without generating typical digital clicks, with dropouts of up to 2.5mm. It continued to play, while generating clicks with the max dropouts of 3mm and failed (stopped playing) with 4mm dropouts. The Denon had no issue with variable linear velocity and/or track pitch, as well as with HF detection. These results are very good, and to be appreciated
Conclusion
The Denon DCD-720AE does not like high level signals, and has a little more distorsion than what I see with many other CD players, from its analog outputs.
The touch and feel, a stable clock, a fast drive that can read heavily scratched CDs, and a "perfect" optical output make this player the ideal companion of an external DAC, for best in class Audio CD experience. The CDA has still a lot of pleasure to deliver to you, and this is a very nice drive.
Enjoy your day!
Last edited:
