Hello everyone,
This is a review and measurements of the Denon DCD-655 CD player and Transport:
Denon DCD-655 - Presentation
This relatively affordable CD player was released in 1999. It reused the conversion architecture of the much more expensive Denon DCD-1650AR, without the specific Denon (ALPHA) filtering.
The elements of interest are :
This Denon DCD-655 had a big brother, the DCD-755AR which lost pitch control but offered CD-Text as well as some improvements, especially in the filtering that went from the SM5841 to the SM5845 (of which I can't find the datasheet).
Here were the published specs:
It is likely that the few dBs of improvements seen with the DCD-755AR were due to the better digital filter having a lower noise floor in audio band. Difficult to confirm in the absence of a datasheet.
On the back of the Denon, we find the standard RCA outputs and a single digital output in Toslink optical SPDIF format:
That’s enough to perform all my tests
Let’s have a look at the inside:
We find the power supply on the top left, mech in the middle and the audio board on the right. Zoom on the latter:
And I said I’d come back to the selected PCM-1702 stamped with an "L":
Not much information are available on the web about these, besides the fact they were specific and undocumented selected chips for Denon.
Some said they were better than the "J" even "K" selections that BB offered, but I very doubted that since that would have made no sense to find them in low value CD players, and Denon would have heavily marketed that.
Before I tell you what made this "L" grade a little more than the non-labelled PCM1702, allow me to come back to these nice BB PCM1702. I already described in great details how this colinear conversion works, it was state of art for R2R conversion, first implemented in the Denon DCD-3560.
In a nutshell, each 20bits PCM1702 is equipped with two internal 19-bit DACs because each one takes care of the positive and negative part of the signal separately, so the first bit (which indicates the sign, aka MSB) is not necessary. So the PCM1702 accepts a 20-bit stream but its internal DACs run at 19bits. That allowed BurrBrown to remove bi-polar zero crossing distorsion (when all bits flip from 0 to 1 in the PCM code). This massive change of bits was generating low level distorsion in R2R DACs. In the colinear conversion, BB had to change the PCM code to be correctly processed by the two internal DACs. That was clever and reason why these DACs were appreciated, at least on an engineering perspective.
Back to the PCM1702 datasheet, and about the different qualitative grades proposed, we find this table of raw performance in terms of distortion, that distinguishes them:
There are therefore 3 qualitative grades based on distortion performance at different levels (0dBFS, -20dBFS and -60dBFS). I guess the respective PCM1702 had to have the performance described in this table, for the three levels, to receive the corresponding grade.
On the picture of the DACs, you will notice that the small "L" seems handwritten, which could have been possible from Korea at the time, maybe?
So, what were the required performances for the DACs to receive an "L"? Certainly not to exceed the maximum performance of the J or K ones, like I assumed before. Since all of my blah blah above was too long, let me cut directly to the measurements of these:
The "L" grade from Denon preserves the hierarchy at full scale (0dBFS), but it would have been eligible for the "K" grade at the lowest level. So that was the selection criteria by Denon, maximum performance with lower levels. In other words, this grade "L" is barely of lower quality than the "K" one, which is very interesting for the consumer. Indeed, if the performance at 0dBFS allows vendors to shine in commercial brochures, it is much less important than a reduced distortion with lower level signals, especially with R2R converters since this is where they suffer most. I say well done Denon!
This Denon is very pleasant to use with the mega fast KSS. And I don’t know who’s the genius who thought about adding a knob to select tracks, instead of the standard next/previous buttons, but it is convenient and very precise. I had a lot of fun, with my 40+ tracks test CDs, testing the speed of the KSS to its limits by jumping 10s of tracks at once in all directions. I got to appreciate the real speed that the KSS-213 is capable of: nothing else but impressive!
Listening to this player was an equal pleasure, like so many others.
Denon DCD-655 - Measurements (RCA outputs)
All measurements performed with an E1DA Cosmos ADCiso (grade 0), 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.
The Denon outputs a low 1.59Vrms, that is 2dB less than the standard 2Vrms. It means when directly compared to another player, it might not shine unless you increase the gain by the same 2dB with your preamplifier.
The tow channels matched at 0.08dB, which is good. The unbalanced outputs invert absolute polarity.
----
As usual, let's start with my standard 999.91Hz sine @0dBFS (without dither) from the Test CD (RCA out):
The distorsion is higher than the best in class, but at -90dBr RHD+N, I’d still say good luck to hear that. The level of THD is what limits the ENOB, but the calculated SNR is very good with that full scale test tone (97.7dB). Note some side rays around the fundamental, they are due to an interaction with the power supply. At -120dBr, they will remain hidden to your ears, of course.
Let's run the same test at -6dBFS as I'm used to:
The distorsion (THD) is the same, which means the PCM1702-L is less at ease with full scale test tones, and that was part of the selection process (better at lower scale).
----
I guess you saw some power supply leakage:
We see 50Hz (Europe) spike and several harmonics, but they are below -110dBr so they will be easily masked into music.
----
Next is the bandwidth:
This is very flat but we get some ringing due to the low performance of the digital filter. And so, let's have a look at how it performs beyond 20kHz:
Yeah, this is low performance with an attenuation of -54dB at worst, just like in the published specs. This filter is relatively sharp, and fully effective before 24kHz.
----
Let's have a look at the multitone test that a lot of you like very much:
This is a very good trace for an R2R converter, and besides a small increase of distortion/noise above 10kHz, it has no issue to stay distortion free beyond 16bits in this complex test. And again, it would have done better with few dBs less, since this "L" grade converter behaves better when below full scale.
----
Let's move on to the jitter test:
I’d say nailed! The red trace is from the digital output of the Denon and the blue one from the RCA outputs.
Note the very low level blue spikes in between that we get to see only because of the very low noise floor, which was advertised this was by BurrBrown in their datasheet:
"More recently, DACs employing a different architecture which utilizes noise shaping techniques and very high over-sampling frequencies, have been introduced (“Bitstream”, “MASH”, or 1-bit DAC). These DACs overcome the low level linearity problem, but only at the expense of signal-to-noise performance"
----
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 mean that it has no headroom in its interpolator oversampling filter, which is not a surprise, unfortunately.
----
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:
The trace is very good, proof of a good analogue section, very silent. Nevertheless, we notice an imperfect symmetry around 0, which means a small lack of linearity at this low level, of exactly 0.86dB. This is rather a good performance for an R2R converter, the Philips TDA1541A deviated by several dB at this level, for instance.
And by the way, this is the strength of delta-sigma conversion, which solved this problem. But it is to be noted that, here, it was no longer a problem either since with "dither" (Random low-level noise that improves linearity by decreasing quantization errors), this Denon is linear down to almost -110dBFS, according to my measurements. So dither (and shape dither) saved 1bit and delta-sigma DACs from high level of quantization errors, but it would have been equally efficient with R2R conversion.
EDIT: By the way, since I'm onto linearity and quality of that CD Player, I add a view of 999.91Hz @-100dBFS of both the DCD-655 and the much higher-end Denon DCD-S10 which was using two PCM1702-J per channel:
Red trace is the DCD-655 and the green one is the S10. Besides the two small spikes at 50Hz and 100Hz, they are the same.
----
Other measurements (not shown):
The DR is at the max of Audio CD format, that’s again an advantage of the type of conversion and proof this player runs silently.
The clock is precise, with only 17.5ppm deviation.
----
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 with the Denon DCD-3560, and the Sony CDP-557ESD to compare:
The sensational Denon DCD-3560, after fine adjustment of the 2MSB, does much better, but the Sony, with one of the most linear standard R2R conversion fine tuned (by me) of the 4MSB, is only a hair ahead.
That means this little Denon competes with some legendary players, and allow me to add another comparison with the very well built Marantz CD-80 and its crowned TDA1541A(S1) converter:
Nice job that the Denon DCD-655 is doing, thanks to the selected DACs.
Denon DCD-655 - Measurements (Digital Optical Out)
Several of you are interested to use CD players as transports only. Let’s check that.
Let's start with my standard 999.91Hz @0dBFS (No dither):
It looks perfect, from what I can tell.
The 3DC levels are equally well represented, meaning no digital attenuation:
Perfect symmetry and that see, as we should (ringing due to Gibbs Phenomenon).
And I thought of one additional test to add to the digital section, and to verify the data are not modified. It is simply reusing the intersample overs test at 5512.50Hz, with a phase shift of 67.5°. This signal generates a theoretical 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 Denon and via the optical out:
The two traces are the same and, to me, all of the above mean "bit perfect" digital output.
Denon DCD-655 - 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 Denon was able to read without generating typical interpolation digital noise with dropouts up to 1.5mm. Beyond that, not only "digital clicks" could be heard but it dropped few seconds.
This is similar to what I measured with other KSS-213 head, and not too bad.
Conclusion
The performance of this R2R conversion is superlative (for what it is) especially on smaller amplitude signals. It features a linearity that a Philips TDA1541A-S1 DAC did not dream of.
The Denon selection of BurrBrown DACs demonstrated tangible benefits. With that, the transition to 1bit or delta-sigma was not really required. In any case, if one is concerned about micro-details in a recording, this Denon will not hide them!
The nice look and ergonomics, together with the super fast drive provide a very satisfying user experience.
As a "transport", this simple CD player is perfect and resistance to scratched CDs is more than decent to make it the ideal companion of a modern external DAC.
I hope you enjoyed this review!
This is a review and measurements of the Denon DCD-655 CD player and Transport:
Denon DCD-655 - Presentation
This relatively affordable CD player was released in 1999. It reused the conversion architecture of the much more expensive Denon DCD-1650AR, without the specific Denon (ALPHA) filtering.
The elements of interest are :
- Advanced Super Linear Converter (ASLC): Denon has often advertised the linearity of R2R BurrBrown DACs. There’s been an obvious very long term partnership between the two companies. The advanced version here refers to the colinear conversion of BurrBrown, first released in the PCM63 and reprised in the PCM1702 in use in that CD player.
- Selected BurrBrown PCM1702-L: one more proof of the partnership, Denon had the possibility to select DACs based on their own specs and they were labelled with an undocumented "L", on top of the standard "J" and "K" selected which were based on THD+N performances at various levels. I’ll talk more about this later.
- Sony KSS-213C laser head: the cheap but still very good and very fast KSS is in use here, as in so many mid-range CD players, sometimes even some higher end too.
- NPC SM5841A/B filtering: It is a 4x or 8x oversampling filter, which also provides digital filtering. I measured that it runs at 8x. It is relatively underperforming with an attenuation of 54dB and ripple of 0.03dB in the audio band, as in the NPC specifications (see the measurement report below).
- Pitch Control: it allows to change, by very precise steps of 0.1%, the reading speed. I’m sure what was the intended use.
This Denon DCD-655 had a big brother, the DCD-755AR which lost pitch control but offered CD-Text as well as some improvements, especially in the filtering that went from the SM5841 to the SM5845 (of which I can't find the datasheet).
Here were the published specs:
It is likely that the few dBs of improvements seen with the DCD-755AR were due to the better digital filter having a lower noise floor in audio band. Difficult to confirm in the absence of a datasheet.
On the back of the Denon, we find the standard RCA outputs and a single digital output in Toslink optical SPDIF format:
That’s enough to perform all my tests
Let’s have a look at the inside:
We find the power supply on the top left, mech in the middle and the audio board on the right. Zoom on the latter:
And I said I’d come back to the selected PCM-1702 stamped with an "L":
Not much information are available on the web about these, besides the fact they were specific and undocumented selected chips for Denon.
Some said they were better than the "J" even "K" selections that BB offered, but I very doubted that since that would have made no sense to find them in low value CD players, and Denon would have heavily marketed that.
Before I tell you what made this "L" grade a little more than the non-labelled PCM1702, allow me to come back to these nice BB PCM1702. I already described in great details how this colinear conversion works, it was state of art for R2R conversion, first implemented in the Denon DCD-3560.
In a nutshell, each 20bits PCM1702 is equipped with two internal 19-bit DACs because each one takes care of the positive and negative part of the signal separately, so the first bit (which indicates the sign, aka MSB) is not necessary. So the PCM1702 accepts a 20-bit stream but its internal DACs run at 19bits. That allowed BurrBrown to remove bi-polar zero crossing distorsion (when all bits flip from 0 to 1 in the PCM code). This massive change of bits was generating low level distorsion in R2R DACs. In the colinear conversion, BB had to change the PCM code to be correctly processed by the two internal DACs. That was clever and reason why these DACs were appreciated, at least on an engineering perspective.
Back to the PCM1702 datasheet, and about the different qualitative grades proposed, we find this table of raw performance in terms of distortion, that distinguishes them:
There are therefore 3 qualitative grades based on distortion performance at different levels (0dBFS, -20dBFS and -60dBFS). I guess the respective PCM1702 had to have the performance described in this table, for the three levels, to receive the corresponding grade.
On the picture of the DACs, you will notice that the small "L" seems handwritten, which could have been possible from Korea at the time, maybe?
So, what were the required performances for the DACs to receive an "L"? Certainly not to exceed the maximum performance of the J or K ones, like I assumed before. Since all of my blah blah above was too long, let me cut directly to the measurements of these:
- THD @0dBFS : -91.2dB
- THD @-20dBFS : -85.9dB
- THD @-60dBFS : -45.8dB
The "L" grade from Denon preserves the hierarchy at full scale (0dBFS), but it would have been eligible for the "K" grade at the lowest level. So that was the selection criteria by Denon, maximum performance with lower levels. In other words, this grade "L" is barely of lower quality than the "K" one, which is very interesting for the consumer. Indeed, if the performance at 0dBFS allows vendors to shine in commercial brochures, it is much less important than a reduced distortion with lower level signals, especially with R2R converters since this is where they suffer most. I say well done Denon!
This Denon is very pleasant to use with the mega fast KSS. And I don’t know who’s the genius who thought about adding a knob to select tracks, instead of the standard next/previous buttons, but it is convenient and very precise. I had a lot of fun, with my 40+ tracks test CDs, testing the speed of the KSS to its limits by jumping 10s of tracks at once in all directions. I got to appreciate the real speed that the KSS-213 is capable of: nothing else but impressive!
Listening to this player was an equal pleasure, like so many others.
Denon DCD-655 - Measurements (RCA outputs)
All measurements performed with an E1DA Cosmos ADCiso (grade 0), 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.
The Denon outputs a low 1.59Vrms, that is 2dB less than the standard 2Vrms. It means when directly compared to another player, it might not shine unless you increase the gain by the same 2dB with your preamplifier.
The tow channels matched at 0.08dB, which is good. The unbalanced outputs invert absolute polarity.
----
As usual, let's start with my standard 999.91Hz sine @0dBFS (without dither) from the Test CD (RCA out):
The distorsion is higher than the best in class, but at -90dBr RHD+N, I’d still say good luck to hear that. The level of THD is what limits the ENOB, but the calculated SNR is very good with that full scale test tone (97.7dB). Note some side rays around the fundamental, they are due to an interaction with the power supply. At -120dBr, they will remain hidden to your ears, of course.
Let's run the same test at -6dBFS as I'm used to:
The distorsion (THD) is the same, which means the PCM1702-L is less at ease with full scale test tones, and that was part of the selection process (better at lower scale).
----
I guess you saw some power supply leakage:
We see 50Hz (Europe) spike and several harmonics, but they are below -110dBr so they will be easily masked into music.
----
Next is the bandwidth:
This is very flat but we get some ringing due to the low performance of the digital filter. And so, let's have a look at how it performs beyond 20kHz:
Yeah, this is low performance with an attenuation of -54dB at worst, just like in the published specs. This filter is relatively sharp, and fully effective before 24kHz.
----
Let's have a look at the multitone test that a lot of you like very much:
This is a very good trace for an R2R converter, and besides a small increase of distortion/noise above 10kHz, it has no issue to stay distortion free beyond 16bits in this complex test. And again, it would have done better with few dBs less, since this "L" grade converter behaves better when below full scale.
----
Let's move on to the jitter test:
I’d say nailed! The red trace is from the digital output of the Denon and the blue one from the RCA outputs.
Note the very low level blue spikes in between that we get to see only because of the very low noise floor, which was advertised this was by BurrBrown in their datasheet:
"More recently, DACs employing a different architecture which utilizes noise shaping techniques and very high over-sampling frequencies, have been introduced (“Bitstream”, “MASH”, or 1-bit DAC). These DACs overcome the low level linearity problem, but only at the expense of signal-to-noise performance"
----
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 |
| TASCAM CD-200 | -73.5dB | -36.3dB | -19.7dB |
| Denon DCD-655 | -34.4dB | -26.8dB | -17.8dB |
I kept some references and will keep the same for other reviews, so you can quickly compare. The results of the Denon mean that it has no headroom in its interpolator oversampling filter, which is not a surprise, unfortunately.
----
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:
The trace is very good, proof of a good analogue section, very silent. Nevertheless, we notice an imperfect symmetry around 0, which means a small lack of linearity at this low level, of exactly 0.86dB. This is rather a good performance for an R2R converter, the Philips TDA1541A deviated by several dB at this level, for instance.
And by the way, this is the strength of delta-sigma conversion, which solved this problem. But it is to be noted that, here, it was no longer a problem either since with "dither" (Random low-level noise that improves linearity by decreasing quantization errors), this Denon is linear down to almost -110dBFS, according to my measurements. So dither (and shape dither) saved 1bit and delta-sigma DACs from high level of quantization errors, but it would have been equally efficient with R2R conversion.
EDIT: By the way, since I'm onto linearity and quality of that CD Player, I add a view of 999.91Hz @-100dBFS of both the DCD-655 and the much higher-end Denon DCD-S10 which was using two PCM1702-J per channel:
Red trace is the DCD-655 and the green one is the S10. Besides the two small spikes at 50Hz and 100Hz, they are the same.
----
Other measurements (not shown):
- IMD AES-17 DFD "Analog" (18kHz & 20kHz 1:1) : -69.6dB
- IMD AES-17 DFD "Digital" (17'987Hz & 19'997Hz 1:1) : -70.9dB
- IMD AES-17 MD (41Hz & 7993Hz 4:1): -79.3dB
- IMD CCIF (19kHz & 20kHz 1:1) : -70.5dB
- IMD DIN (250Hz & 8kHz 4:1) : -76dB
- IMD SMPTE (60Hz & 7kHz 1:4) : -76.8B
- IMD TDFD Bass (41Hz & 89Hz 1:1) : -97.3dB
- IMD TDFD (13'58Hz & 19841Hz 1:1) : -84.8dB
- Dynamic Range : 98.2dB (without dither @-60dBFS)
- Crosstalk: -108dBr (100Hz), -108dBr (1khz), -90dBr (10kHz)
- Pitch Error : 19'996.67Hz (19'997Hz requested) ie 17.5ppm
- Gapless playback : Yes
The DR is at the max of Audio CD format, that’s again an advantage of the type of conversion and proof this player runs silently.
The clock is precise, with only 17.5ppm deviation.
----
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 with the Denon DCD-3560, and the Sony CDP-557ESD to compare:
The sensational Denon DCD-3560, after fine adjustment of the 2MSB, does much better, but the Sony, with one of the most linear standard R2R conversion fine tuned (by me) of the 4MSB, is only a hair ahead.
That means this little Denon competes with some legendary players, and allow me to add another comparison with the very well built Marantz CD-80 and its crowned TDA1541A(S1) converter:
Nice job that the Denon DCD-655 is doing, thanks to the selected DACs.
Denon DCD-655 - Measurements (Digital Optical Out)
Several of you are interested to use CD players as transports only. Let’s check that.
Let's start with my standard 999.91Hz @0dBFS (No dither):
It looks perfect, from what I can tell.
The 3DC levels are equally well represented, meaning no digital attenuation:
Perfect symmetry and that see, as we should (ringing due to Gibbs Phenomenon).
And I thought of one additional test to add to the digital section, and to verify the data are not modified. It is simply reusing the intersample overs test at 5512.50Hz, with a phase shift of 67.5°. This signal generates a theoretical 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 Denon and via the optical out:
The two traces are the same and, to me, all of the above mean "bit perfect" digital output.
Denon DCD-655 - 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 1.5mm |
| Combined dropouts and smallest pitch | From 1.5µm & 1mm to 1.5µm & 2.4mm | up to 1.5mm |
| Successive dropouts | From 2x0.1mm to 2x3mm | up to 1.5mm |
The Denon was able to read without generating typical interpolation digital noise with dropouts up to 1.5mm. Beyond that, not only "digital clicks" could be heard but it dropped few seconds.
This is similar to what I measured with other KSS-213 head, and not too bad.
Conclusion
The performance of this R2R conversion is superlative (for what it is) especially on smaller amplitude signals. It features a linearity that a Philips TDA1541A-S1 DAC did not dream of.
The Denon selection of BurrBrown DACs demonstrated tangible benefits. With that, the transition to 1bit or delta-sigma was not really required. In any case, if one is concerned about micro-details in a recording, this Denon will not hide them!
The nice look and ergonomics, together with the super fast drive provide a very satisfying user experience.
As a "transport", this simple CD player is perfect and resistance to scratched CDs is more than decent to make it the ideal companion of a modern external DAC.
I hope you enjoyed this review!
Last edited:
