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Sony CDP-557ESD/707ESD (CD Player)

NTTY

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Hello Everyone,

This is a review and detailed measurements of the Sony CDP-557ESD CD Player, also known as the Sony CDP-ESD707 in US and Canada.

Sony557ESD_001.jpg



I already reviewed the little brother Sony CDP-337ESD, so that will be interesting to compare the two. Did Sony achieve to create a better CD player with BurrBrown conversion instead of best in class implementation of the Philips TDA-1541A DACs? Let's find out.


Sony CDP-557ESD - Presentation

If the 337ESD was already playing in the heavy weight category, this one adds a lot more, reaching 18kg (40lbs)! This is more than many amplifiers.

The Sony CDP-557ESD was released in 1987, that is 37 years ago, and I think it still looks absolutely gorgeous. The available information about this player, on the web, are limited and partially wrong. Let me correct that.

The elements of interest are:
  • Impressive built: Massive Gibraltar chassis, copper plated, with mechanical separation between (the two massive) transformers, and the beautiful all metal meh (rare KSS-190 head). When doing well and at no cost consideration meant something...
  • D/A architecture: Very rare BurrBrown PCM64 (R2R) DACs, with parallel inputs. This DAC is not so well documented but was intended for "low distortion frequency synthesis and very high end consumer and professional digital audio applications". This DAC is based on the DAC729 of which purpose was to be used to provide very accurate signals in dedicated measurement devices.
  • 4 MSB trimming: What attracted my attention is the fine tuning of the first 4 bits, which is rare and not easy to use (and not documented in the datasheet I could find). This is not a first for BB (the PCM58 also offered this feature), but it’s not easy to find a player where it was implemented.
  • 8x oversampling: we get the famous CXD1144, which is found in the CDP-337ESD, followed by a CXD1305 which is a serial to parallel converter to feed the BB DACs.
  • Superb full metal drive with the ultra fast KSS-190 laser head.
The back of the player is relatively standard:

Sony557ESD_002.jpg



We have only RCA outputs for the analog (one variable and controlled by the phones volume), and coax + toslink for Digital. What you see on the left is an additional coax output. Someone thought they could do better than Sony, and an army of engineers, to improve the digital output :facepalm:

This is the inside of the beast:

Sony557ESD_003.jpg



The two BB PCM64 are hidden below some ceramic pads. And here are the 4 MSB adjust per converter (RV401 to RV404 for right channel):

Sony557ESD_004.jpg


Notice the beautiful power copper rails, like in the Teac VRDS 25x.

And, oh, yes, horror show:

Sony557ESD_005.jpg


This is were someone picked the digital signal to create a second digital output. Wanna know what? It's crap output, surprise...

In fact, I suspect there was an attempt, by the same person, at making this player "sound better", playing with the 4 MSB trimming. This was the result:

1743182084856.png


Shame, barely 14 bits of resolution for one of the best player ever made, come on...

Let me (try to) fix all of this and show you how this player can truly perform. My reference to beat, in terms of R2R conversion, is the Denon DCD-3560. The fight will be interesting.

Other than that, the drive is faster than light, it's a pleasure to use.


Sony CDP-557ESD - Measurements (Analog Out)

All measurements performed with a Cosmos E1AD (grade G).

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 Sony CDP-557ESD outputs a very precise 2Vrsm from its RCA outputs. The two channels were perfectly balanced (0.00dB), rare... The single-ended outputs are non-inverting.

After a quick adjustment of the 4 first most significant bits, I got a much better result than what I showed above. I think with more time and attention, I can do better. I'll certainly publish a "How to" later in this thread, when time allows.

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

SonyCDP557ESD_999.91Hz_0dBFS.jpg


Hell yeah, compared to when I first measured it, we see nearly 20dB less in distortion and 11dB in noise!
With a THD of -103.4dB, the Sony gets very close to the dual BB PCM58 of the Denon DCD-3560. Well done Sony. I'll update if I achieve to do better.

Next is the same view but at -6dBFS, as I usually show:

SonyCDP557ESD_999.91Hz_-6dBFS.jpg


THD is still impressively good (very close to -100dBr), and noise is limited by the one of the format. As a matter of fact, these two measurements are very close to those of the Denon DCD-3560.

The power supply is quiet, with spuriae below -120dBr:

SonyCDP557ESD_PS.jpg


We see them because I use a 512k FFT size and average 32 times. So that's good result from the Sony.

Next is the bandwidth (now measured from a long term average of periodic white noise):

SonyCDP557ESD_BW.jpg


This is very flat despite the zooming. No difference in channel balance as I already written. Obviously the Sony oversampling filter does a good job. Let's have a detailed look at how it performs:

SonyCDP557ESD_OS_Filter.jpg


We can't see the aliases of 18kHz and 20kHz, everything is below -100dB. That was best in class at the time.

No noise shaping technique shows here, though, this is good old R2R conversion with "standard" oversampling after all. That said the two spikes above 30kHz are of unknown nature to me. I think I'll have a detailed look and the rest of the electronics and maybe some caps would need a refresh, I'm unsure. I also need to remove that ugly additional Coax output anyways.

Multitone (1/10 decade) shows a happy CD player, not having issue to clear 16bits of data:

SonyCDP557ESD_MT.jpg


This is the Jitter test:

SonyCDP557ESD_JTest.jpg


The red trace is from the digital output (the original one, of course) and the blue is from Analog output. There's minimum noise, it's near perfect. That means Jitter was a no issue 37 years ago...

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
Sony CDP-557ESD-30dB-24.4dB-16.5dB


I kept some references and will keep the same for other reviews, so you can quickly compare. The results of the Sony CDP-557ESD mean that the oversampling filter does not have headroom to prevent intersample-overs. The Yamaha CD-1 shines here because it's old enough not to have an 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:

SonyCDP557ESD_3DC_Fixed_R.jpg


What a beautiful trace! We expect to see the 3DC levels as, at this very low -90.31dBFS, we can only get a square. The ringing is due to the Gibbs Phenomenon as we are in band limited. This is a very silent player.

Other measurements (not shown):
  • IMD AES-17 DFD "Analog" (18kHz & 20kHz 1:1) : -95.2dB
  • IMD AES-17 DFD "Digital" (17'987Hz & 19'997Hz 1:1) : -99.2dB
  • IMD AES-17 MD (41Hz & 7993Hz 4:1): -110.3dB
  • IMD CCIF (19kHz & 20kHz 1:1) : -98.8dB
  • IMD DIN (250Hz & 8kHz 4:1) : -93.3dB
  • IMD TDFD (13'58Hz & 19841Hz 1:1) : -118.8dB
  • IMD TDFD Bass (41Hz & 89Hz 1:1) : -112dB
  • IMD SMPTE (60Hz & 7kHz 1:4) : -93.4dB
  • Dynamic Range : 98.6dB (perfect)
  • Crosstalk: -130dB (1khz), -120db (10kHz)
  • Pitch Error : 19'997.09Hz (19'997Hz requested) ie 4.5ppm
The above are excellent results, we are clearly in the SOTA of the time.

Last and not least, my preferred measurement which is a sweep of THD vs Frequency @-12dBFS:

SonyCDP557ESD_THDvsFreq.jpg


I overlaid with the little brother 337ESD and its staggered TDA1541A, and of course with the Denon DCD-3560, as the one R2R converter to beat. Well, the Sony CDP-557ESD does indeed good, but not equal to the big Denon. I maybe able to do better, allowing myself more time to fine tune the 4 MSB. I'll update if that's the case.


Sony CDP-557ESD - Measurements (Optical 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.

This is one very stable digital output, which I don't see that often. It means I had no issue getting a constant reading without windowing errors in the FFT calculation that I often suffer, due to the absence of PLL to filter the clock deviations. I was therefore able to run the test up to my desired 32 averages.

The digital output is as what we expect it to be, perfect (999.91Hz @0dBFS without dither):

SonyCDP557ESD_999.91Hz_0dBFS_Coax.jpg


I really wonder why one thought they could better than perfection. Well actually, they achieved to do different as my interface could not read anything out of the additional Coax output :facepalm:

Anyways, this is a perfect transport, thanks Sony.


Sony CDP-557ESD - 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 1mm.

The drive was able to consistently continue playing, without generating typical digital clicks, with dropouts of up to 1.25mm. The interpolation effect remained hidden to my ears when it kicked-off but failed to maintain a constant flow beyond 1.25mm. The Sony had no issue with variable linear velocity and/or track pitch, as well as with HF detection. These results are aligned with the other Sony drives I tested.


Conclusion

I was really impatient to play with the 4 MSB trim pots of the BB PCM64. It's only the beginning of fun for me, as I need to look into the details of that player.

This was a crazy device at the time, and it still is, on my perspective. The performances, as is, are already above the CD Audio, so we get to listen to the master and nothing else.

A master piece.

Stay tuned and enjoy your weekend!

————
Flo
 
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Dang. Why is it that I never managed to find any of the Sony "ES" series CDPs on the swap pile at the good ol' Harvard, MA town dump transfer station - only the non-ES morphs? :( ;)

Thanks for sharing the post, the review, and the data!
 
Every new NTTY's review is a joy to read. :) :p

I just want to address that technical point :
  • 8x oversampling: As opposed to what's written in many places, the digital filter is not the CXD1144, which is found in the CDP-337ESD, but one that has a parallel output to go with the BB DACs. And that is the Sony CXD1305 in mono mode (there's one per PCM64).


View attachment 439873

From what can be seen in the relevant service manual and on the above quoted photo, there is indeed a CXD1144 digital filter (middle lower chip). The CXD1305 appears to be a serial to parallel data converter whose function is to drive the DACs inputs from the CXD1144 serial data output.

I am curious to see if the signal out of the added digital output is as horrible as the mod looks.
 
@Scytales Merci! I was too fast and got it wrong. I updated the text from your input.
I can’t show you anything out of the additional coax output. I see only noise coming out of it, when I see something. It’s a first. I might analyze it with a scope, but I don’t think it’s worth my time. Better to spend time removing that abnormality :)
 
:facepalm:

The best of this SONY somehow did not get a prominent mention.
The drawer mechanics is just awesome.
 
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If only noise comes out of the added digital out, it's an horror show indeed! Or perhaps a failed attempt or a defect.

I see in the service manual that the analogue post-dac filter is a generalized impedance converter (GIC). I wonder if the CDP-557ESD is the first CD-player in which Sony has implemented that type of filter.

I quickly simulated the filter with Caneda: it appears to have a -3 dB corner frequency at around 70 kHz with an attenuation rate of 6dB/octave.
 
:facepalm:

The best of this SONY somehow did not get a prominent mention.
The drawer mechanics is just awesome.
Indeed, some of the text got dropped, I made mistakes before publishing. Thanks for telling me, I added a mention.
 
If only noise comes out of the added digital out, it's an horror show indeed! Or perhaps a failed attempt or a defect.
Maybe an issue in 800km that separated it from me. But I doubt.
The previous owner sent me a video of this output being connected and it played music. That said, on this video, he switched between the stock coax output and this one. And I saw he had to turn twice the connector to get sound, which I suppose indicates only difficulty for the DAC to sync on the incoming data. I can’t be sure. I might try to connect it to a DAC. Maybe the PLL can filter out all the garbage I saw.

I see in the service manual that the analogue post-dac filter is a generalized impedance converter (GIC). I wonder if the CDP-557ESD is the first CD-player in which Sony has implemented that type of filter.

I quickly simulated the filter with Caneda: it appears to have a -3 dB corner frequency at around 70 kHz with an attenuation rate of 6dB/octave.
Interesting, thanks for the information!
 
This is a draft.

The BurrBrown PCM64 is a rare R2R 18bits DAC that was found in few high-end CD players at the end of the 80s'. It is deviated from the DAC729 which was intended to be used in instrument type of devices because of its high precision (claimed distorsion at max 0.0009%). The PCM64 is a lower cost version of it, retaining the basic principles and allowing for a less stringent operational stability. As the DAC729, the PCM64 features a 4 MSBs optional trimming, which was not offered on all CD players were it was implemented. It makes this Sony 557-ESD even more unique as we find the 4 trimming pots to play with (Bit1 to Bit4). By the way, the DAC729 was never implemented in a CD player.

The PCM64 does not feature a zero-order hold function which must be done outside the DAC, and the schematics of the Sony show this is done with couple of NE5534, yes the (very) good old one. If you search for the datasheet of the PCM64, you'll find it's incomplete, maybe it remained as a draft forever. But we can partially complete the missing information from the DAC729 and also looking at the way it's implemented in that Sony player.

All of that means we are looking at the SOTA of the time.

The 4 bits adjustment procedure is not described in the PCM64 datasheet. But there is one described in the DAC729 and it is based on 18bits codes to send to the DAC, which is not possible from an audio CD. That being said, this procedure provides us with interesting information as to how to best perform it, and what to expect. This is it (extracted from the DAC729 datasheet):

FOURTH MSB ADJUSTMENT (Pin 36)
I. Set Code = 11 1100 0000 0000 0000
2. Measure VOUT
3. Set Code = 11 1011 1111 1111 1111
4. Measure VOUT and record the difference.
5. Adjust 4th MSB potentiometer to make difference +38µV.
6. Repeat steps I through 5 to confirm.

THIRD MSB ADJUSTMENT (Pin 37)
I. Set Code = 11 1000 0000 0000 0000
2. Measure VOUT
3. Set Code = 1101111111 1111 1111
4. Measure VOUT and record the difference.
5. Adjust 3rd MSB potentiometer to make difference +38µY.
6. Repeat steps I through 5 to confirm.

SECOND MSB ADJUSTMENT (Pin 38)
I. Set Code = 11 00000000 0000 0000
2. Measure VOUT
3. Set Code = 10 1111 1111 1111 1111
4. Measure VOUT and record the difference.
5. Adjust 2nd MSB potentiometer to make difference +38µV.
6. Repeat steps I through 5 to confirm.

MSB ADJUSTMENT (Pin 39)
I. Set Code = 10 0000 0000 0000 0000
2. Measure VOUT
3. Set Code = 01 1111 1111 1111
4. Measure VOUT and record the difference.
5. Adjust the MSB potentiometer to make difference +38µv.
6. Repeat steps I through 5 to confirm.
Note that the 38µV requested is because this test is based on 10Vpp at 18bits resolution, and so 10/262'144=38µV. It means this procedure allows to fine tune the precision to be below 1/2LSB on the 4 first bits. We could theoretically adjust it for Audio CD, since the last 2 bits could be ignored in that process, as you can see. But because there is the oversampling filter before the DAC, it would modify the digital code, so we have to find another solution.

The Service Manual of the Sony shows a procedure described as below (copy/paste from the SM):

Distortion Adjustment
This adjustment should be made only when replacing D/A converter and components of the -15V system power supply block.

1. Put disc (YEDS-18) in and playback 1kHz, 0dB signal track (second track).
2. Adjust the following volumes in order given by arrows so that the distortion is minimum:
L-CH: RV404->RV403->RV401->RV402
R-CH: RV504->RV503->RV501->RV502
3. Confirm the specification is satisfied. When out of specifications, repeat item 2 and 3 several times
Specifications: 0.003% and below.

As you can see, we are supposed to use a 1kHz full scale sine tone which, to me, is surprising. The reason is that the MSB is the signed bit, and I would not tune this one from a high level signal, quite the contrary in fact. That said, it's interesting to note that the Sony's procedure makes us trim the respective bits in this order: 4->3->1->2. So the MSB (bit1) is to be adjusted after bit3 and before bit2. I think it makes sense, but I'm not sure it's the best way. It might have been a not too complex and too long procedure though, or maybe the available distorsion analyzers of the time could not help better.

Anyways, I went for it as described by Sony, and I got a good result (THD=-103.3dBr, THD+N=-96.6dBr). I did it looking in real time at non-averaged FFT and trying to lower H2 up to H9, also trying to have a good balance of them, I mean preventing high harmonic spikes, even beyond H9, actually:

1743529027810.png


That said, and without surprise (to me), this procedure does not allow for high precision linearity at lower scale. So I added a second procedure, to follow after the one of Sony, and it goes like this:
1 - Play a 997Hz sine at -90.31dBFS
2 - Adjust Bit1 so that H2 can't be seen AND input level is as close as possible to -90.31dBFS
3 - Alternatively, if an FFT analyzer is not available, use a scope and adjust until symmetry is achieved between positive and negative signals, with a crossing level at exactly 0V.

With that complementary procedure, I slightly improved the THD result at full scale:

1743529125787.png


You see that as a result of this additional adjustment, the distortion profile changed and lowered.

More interestingly, I improved THD at all lower levels including the one where I like to compare CD players' performances, and that is -12dBFS. Here you go with the result that you can compare with the one I initially put in the review:

1743528535384.png


Not only that, but doing so, the linearity of the Sony reached 16bits easily without dither (of course since I tuned it for that), and went up to XXbits with dither (TBC). So I think adding my procedure to the one of Sony is not a bad thing :)

In the end, and compared to my "reference" R2R conversion from the Denon DCD-3560 (which uses a very complex conversion architecture), the Sony missed the mark by only 0.5dB on the above test (see the plot at 1kHz). This is very good result since the Sony uses only one DAC per channel where the Denon has two (PCM58 in their most linear version K).

And voilà, this PCM64 is probably the best 18bits R2R DAC that BurrBrown released. The draft of the PCM64 datasheet mentions a J and K version of that chip, but those in the Sony are unmarked, as well as in the other players that used it, as far as I know. I'm not sure of what that means, but maybe that there were not enough differences between them(?).

I'll continue to think about all of that, and maybe you'll have feedback for me to improve via different options.

Cheers
 
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