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Marantz CD-73 Review (Vintage CD Player)

NTTY

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Hello Everyone,

This is a review and detailed measurements of the Marantz CD-73 stereo player.

CD73-006.jpg



In my previous review of the Marantz CD6007, I said I was into older CD players, here is the proof :)


Marantz CD-73 - Presentation

Do I really need to present this one? Let's be quick, there's already so much on the web about this player.

Released in 1983, it was my first CD Player, and I must say I still love the look 41 years later! Of course, it's still spinning CDs, and it reads burnt CDs too, which allows my to share this review with you. The Marantz only required fixing the power supply to be as good as new. So let's torture a bit this vintage dinosaur.

It hosts two mono DACs from Philips, the TDA1540 that some believe to be magical, if not legendary. They run at 14bits only, when Sony went 16bits DACs at the same time. But, but, but, Philips (and therefore Marantz) had a trick in their hat, a 4x oversampling filter including noise shaping! The noise shaping is what restrict quantizing noise when going from 16bits to 14bits. Much later, this technique was used to save the 1bit DACs from generating too much quantizing noise in the audio band. It's still the same today.

Back panel has only analog outputs:

CD73-007.jpg


At it is so much fun to see the CD spinning though the top window:

CD73-008.jpg


In terms of utilization, it’s really obsolete and relatively slow. It's possible to skip forward a track, but not backward, and it's really annoying. Beyond track 15, it goes blind (there are only 15 led to show the current track being played), so on my 44 tracks test CD, I had to stay concentrated on what track it was possibly reading.

The specs of the time were the below:

CD73-010.jpg


Time has come to verify.


Marantz CD-73 - Measurements (Analog out)

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 for the Onkyo C-733 review. Over time, this will help comparing the devices I reviewed.

The Marantz CD-73 outputs 2.09Vrsm, no surprise here. The RCA outputs do not invert polarity and there is a 0.1dB imbalance between the two channels.

Here you go with my new standard 999.91Hz sine @0dBFS (without dither) from the test CD (RCA out) :

CD73_999.91Hz_0dBFS_LR.jpg


Both channels are represented but only one gets evaluated in that window. Left channel is a little less performing, but both are very similar, which is not always the case with mono DACs from separated chips.

You see that despite the 14bits resolution of the DAC, the dashboard reports an ENOB 14.7bits. Distortion is low, for the format, at -89.3dB (0.0034%), but real limitation is the noise floor which is raised because of the 14bits/noise shaping of the conversion. And the SINAD is only 87dB.

From now on, I add the same view but at -6dBFS:

CD73_999.91Hz_-6dBFS_LR.jpg


You probably already noticed too, this is a relatively quiet CD player, with minimum power supply–related spuriae in its output (below -120dB at 50Hz) :

CD73_PowerSupply02.jpg


There's little spike at around 640Hz, per the insights of @bramjacobse is the Wobble Generator used for Tracking. It's at -110dB, very unlikely to be heard in the raised noise floor of the CD-73. In the end, this is very good.

Now, let's have some fun with the bandwidth :

CD73_BW.jpg


First, the mismatch between the two channels is only 0.1dB which is good. What you see, at the frequency end, is the oversampling filter ringing because of lack of power (at the time).
And I thought it'd be funny to compare this result with the Philips CD 104 which hosted the same technology:

1729176966806.png


You see that the Marantz adds some gentle roll off at lower end of the bandwidth. It could have been intentional. Check out Cambridge Audio CD1 CD player Measurements from Stereophile, you will find resemblance between the filters selection that this player offered. Other than that the Marantz and the Philips are the same since they share the exact same conversion.

Staying the oversampling filtering effect, let's have a look at wide band (up to 96kHz) :

CD73_BW_TripleTones_L.jpg


This an overlay of periodic white noise (pink) and triple tomes (9kHz, 19kHz and 20kHz). It shows the ringing of the filter. Out of band attenuation is only 55db (see the green spikes of images form the triple test tones), but better than what the Marantz CD6007 achieves with CD Audio, if you ask me.

Let's continue with the multitone test (1/10 decade) :

CD73_MT_LR.jpg


Both channels are shown and again left one is a little noisier. We see it's difficult for the Marantz to clear more than 90dB of free distortion range. But it's not too bad for a 14bits DAC!

The CD-73 showed reasonable amount of Jitter (measurement to update with new file). It adds a little amount of Jitter around 7kHz and 15khz, so that are sidebands at +-4kHz. Hopefully, they are at very low level, impossible to hear way below -100dB.

With a 14bits DAC and despite oversampling + noise shaping, I wondered what would happen with an undithered 1kHz sine at -90.31dBFS. With 16bits, the signal should appear (on a scope) as the 3DC levels of the sign magnitude smallest digital signal, and it should look like this (digital output of an Onkyo C-733) :

Onkyo_C-733_3DC_Opti.jpg


But now, what if we have to drop 2 bits in the DAC. Is our signal completely gone into the noise? Here you go :

CD72-1kHz_-90.31dBFS_L.jpg


Wow, we can still recognize it. I honestly thought it'd be completely buried into noise. We can see lack of linearity here though. The lower part of the signal is not at the correct level.
And by the way, the CD-73 loses linearity at -70dB (by 0.7dB) which again is not so bad considering its DACs runs at only 14bits and it is R2R architecture, less linear than 1bit by design.

This is the Jitter Test:

CD73_JTest.jpg


We see some side bands but they are very low at -110dBr so they will remain masked into music. This is very decent results for the time.

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
Marantz CD-73-50.3dB-52.0dB-27.7dB

I left several other references for you to compare with. The oversampling filter to the Marantz CD-73 has a headroom of around 2dB to process Inter-sample overs, which is very good. The Yamaha CD-1 shines in that test because it does not use an oversampling filter.

And I forgot to add other measurements:
  • DR : 93dB (1kHz @-60dBFS without dither)
  • Crosstalk : -110dB (@1kHz)
  • IMD AES : -87.9dB (18kHz + 20kHz 1:1 @-3.02dBFS)
  • IMD SMPTE: -76dB (60Hz & 7kHz 4:1 @-1.68dBFS)
What else? Oh yes, of course, one of my favorite measurement, the THD vs Frequency at -12dBFS. I already commented elsewhere that I use it especially to test older R2R architectures as it shows their difficulty to be linear below full scale. Below is measurements of the Left and Right channels, overlaid with the previously tested (and near best in class for a CD Player) Onkyo C-733 :

CD73_THDvsFreq_-12dBFS.jpg


There you go with a massive difference. This shows 20 years of DAC evolution in a CD player. That is 15 to 18dB more THD in the Marantz, which is huge. And well, -80dBr harmonic distortion, I know I can't hear. So I'm not really concerned, but I'm happy to witness this evolution over time.


Conclusion

I hope you enjoyed reading this review as much as I enjoyed writing it.

Why are these old players so praised? Because they generate a lot more distortion and noise than newer ones? Maybe, but I doubt.

What I don't doubt about is that this player can still today please my ears. What else?
Of course, it does not imply it would satisfy yours, but you know what? Just ask me to record a track of your choice, I’ll do it and send to you ;)

I hope you enjoyed the review, and again let me know how to improve and if you have questions.

Thank you.

--------
Flo
 
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Fascinating. I love seeing some of this older tech tested. I think your -12dBFS THD test is very informative!
 
Brillant! Thanks a lot for measuring (and publishing) this venerable CD player. I guess it will be promoted to the front page.

Thanks again!
 
Mid 1980's player with 1540 chip and still spinning. Incredible. Have you replaced some of the caps and serviced the unit or all the internals are factory stock ?
 
Yes, power supply needed some caps to be replaced, nothing major.
 
"There's little spike at around 640Hz but I don't what's causing it. It's at -110dB, very unlikely to be heard in the raised noise floor. In the end, this is very good."

640Hz is the +/- 650Hz Wobble Generator used for Tracking, it's added into the Radial Servo Control
 
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@bramjacobse: You may want to revisit trimming on the Elektuur PCM63 DIY DAC, a PCM63P-K is spec'd with -108 dB THD+N typical untrimmed already and I almost can't believe that linearity can't be improved (the best PCM63-based DACs I've seen basically went down to -120 dB, but without having looked those results back up I can't guarantee that there wasn't some PMD100/200 magic involved). The output stage also seems to be a bit unhappy at higher frequencies, but without a schematic it's hard to tell why.
 
Goes to show that the performance even among the very first CD players where very good. Sure not compared to todays standard, but from an absolute audibility level for humans they are still very good which is all that really matters imo!
 
640Hz is the +/- 650Hz Wobble Generator used for Tracking, it's added into the Radial Servo Control
I remember I heard it when listening to the silent gaps between tracks and raising the volume all way up for a second. The CD73 was my first player when prices dropped. Unfortunately I sold it, being unaware of the built quality. All first and seccond generation players use the Sharp-LT022MC laser diode, the only diode that was available at that time. Looks like these diodes were to last.
 
I finally found time to update this review with the latest test set, so I added:
  • 999.91Hz @0dBFS and -6dBFS, that are without dither (because that frequency "self-dithers")
  • Jitter test
  • Inter-sample over tests
  • Multitone now at 1/10 decade instead of 1/20 previously
  • Revised IMD tests (more stringent)
  • Updated comments
Enjoy!
 
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