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Teac VRDS-20 Review (CD Player)

NTTY

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Hello Everyone,

This is a review and detailed measurements of the Teac VRDS-20 stereo CD player.

TEAC-VRDS-20_001.jpg


I already mentioned multiple times that I’m into older CD players (like the Marantz CD-73), this is one more proof.


Teac VRDS-20 - Presentation

This CD player made me dream when I was much younger. It was way out of my league at the time.
It was released in 1993 at a very high price, featuring a unique look in the Teac range, with the 4 adjustable pillars at each corner. It was available in black and gold.

It plays only the initial silver disc, no SACD, no USB input, no, no Bluetooth either, sorry :p No digital inputs, too bad, Teac could have made an effort here.

The elements of interest are:
  • The VRDS (Vibration-free Rigid Disc-clamping System) mechanism of course! This is the version CMK-3.2 with resin (or polymer, I’m not sure) molded “bridge” over the (aluminum) clamper that is supposed to reduce vibrations of the disc when rotating. Below that is the Sony KSS-151A magnetic head, one of the most reliable, fastest head. And 30 years later, it runs flawlessly.
  • D/A architecture (thanks to @AnalogSteph for the deep dive): A double mono conversion via two stereo Philips TDA1547 converter which was the first and high-end 1bit conversion of Philips, at the time. It is seconded by the Philips noise shaping (SAA7350) which is necessary for rejection of the noise generated by the decimation to 1bit. Preceding the SAA7350 is the oversampling and filtering function provided by an NPC SM5840 that runs at 8 times. If the SAA7350 could be used to convert directly, as it includes a 1bit DAC too, the couple SAA7350 + TDA1547 was the high-end conversion offer of Philips, and it was called DAC7.
  • Incredible mechanical construction: it does not stop at the VRDS as the entire device is built like crazy, with attention to every detail (I’ll come back to that later). As such it looks like an “Esoteric” before the time, and before it became a brand as such, outside of Japan.
Back panel has RCA and XLR analog outputs. We also find standard digital coax and Toslink, with a less standard St optical out:

TEAC-VRDS-20_003.jpg


There’s a window on the top of the player, the VRDS mech had to be seen.

TEAC-VRDS-20_009.jpg


As with many of these old players, and despite the complex and heavy VRDS, it is super-fast to skip one or multiple tracks back and forth (thanks to the Sony KSS-151A). With the big buttons on the front, very easy to read, it’s only a pleasure to use.

Before we go to measurements, let me guide you to the inside, because it’s worth a detour.
Below the aluminum top, we find … a second steel cover, and after removal of side panels with the 4 pillars, we find … a third copper cover. Really? :)

TEAC-VRDS-20_018.jpg


When finally inside, we are faced with something NASA-class built, except that it’s too heavy to go into a satellite :eek:

TEAC-VRDS-20_012.jpg


The player is divided into 4 sections:
  • VRDS mech in the middle
  • Power supply behind the drive
  • Servo card and digital out on the right
  • D/A conversion (with oversampling and noise shaping ICs) and analog out on the left
This is very neat, and attention to details goes as far as adding a copper pad on critical components as you can see above on the two TDA1547. I guess this is again NASA-habit to protect 0s and 1s from spatial radiations which could change their status? :cool:

I will spare you more details as I guess you want to know how this nuclear plant measures. But note that below the beautiful VRDS bridge (not decorum in this player, as it was with the T1 transport for instance), the aluminum clamp is so heavy that it requires a small disc brake with a caliper and respective pad. Why make it simple?


Teac VRDS-20 - Measurements (Analog out)

From now on, I will be consistent with my measurements as I described them on the Onkyo C-733 review. So over time, this will help comparing the devices I reviewed.

The Teac VRDS-20 outputs 1.9Vrsm from its RCA outputs and 3dB more from XLR (2.62Vrms). RCA and XLR showed the same performances, only a little more power supply noise from RCA.

Here you go with the standard 1kHz sine @0dBFS (dithered) from my test CD (XLR out):

TeacVRDS20_1kHz_0dBFS_LR.jpg


Both channels are represented but only one gets evaluated in that window. Left channel is a little less performing (THD loses 4dB). That kind of difference happens especially when two different DACs running in mono mode are used.
THD sits at -104dB and so will clear CD Audio content. SINAD and ENOB are limited by the dithered noise of the test CD (roughly -93dB).

XLR and RCA are very close in performance, except that RCA has more power supply related noise.

It is to note that distortion stays very low even when digital signal goes down, which was not always the case with old DACs. As seen below, THD is still at -105dB at -6dBFS:

TeacVRDS20_1kHz_-6dBFS_RCAvsXLR_LvsR.jpg


This is an overlay of left and right channels, from RCA and XLR out, so you get the best (XLR right) and the worse (RCA Left) at once. THD is well below -100dB which is very good for the time. Overall, the trace shows some “grass” of harmonic and non-harmonic low level distortions, but that’s not a surprise for a 1bit DAC and is well contained considering this was the first iteration of Philips (more than 30 years ago).

The datasheet of the TDA1547 specifies a best case THD of -88dB at -20dBFS (worst case is -84dB). And -88dB THD is very precisely what I get from the Teac. In other words, best possible implementation of that DAC here, thanks to mono mode too.

You probably already noticed, there is a little power supply leakage (50Hz and harmonics) which, even if without negative consequences at this very low level, I would have preferred not to see (1kHz @0dBFS, XLR out, left and right channels):

TeacVRDS20_1kHz_0dBFS_PowerSupply_LR.jpg


That said, the player being 30 years old could explain this.

Now, let's have a look at the bandwidth:

TeacVRDS20_Bandwidth.jpg


There’s a 0.1dB channel mismatch, and the service guide says it’s a pass up to 0.5dB, so I shall be very happy :)
We can see the oversampling filter ringing at the end of the frequency range. This is typical of oversampling filters lacking some power. And so, staying with the oversampling filter effect, let's have a look at wide band (up to 48kHz):

TeacVRDS20_FiltreResponse_02.jpg


This an overlay of periodic white noise (red trace) and dual tones (18kHz and 20kHz). It shows the ringing of the filter. Out of band attenuation is only 60db (see the blue spikes of images from the test tones at 26.1kHz and 24.1kHz respectively). To be honest, I was disappointed to see that, even if better performing, it is similar to previous 4x oversampling filters of the era, especially the one of Philips. But I’ve seen better 8x filters of the same time both on ripple and attenuation.

So, was it intentional from Teac?

If one was to attribute a sound characteristic to such oversampling filters, and if it was believed to be the reason why the previous Philips converter TDA1541 and its associated filter SAA7220 were praised, then it could have been intentional. It is important to remember that the DAC is only the final part of the digital journey before reaching our amplifiers and speakers. DAC filters work well with matching ADC filters, and are ideal in that case.

At the time, the CD catalogue was already significant, most of it being built from Analog maters. The ADC digital filtering in use, to reject out of audio band frequencies, lacked power too and were likely to match what you see above (my guess). That’s the reason why I (like to) think this was intentional from Teac. Let me dream :) It could very well be a (less poetic) technical partnership to satisfy too, and so many other reasons.

Let's continue with the multitone test (1/20 decade):

TeacVRDS20_Multitone_L.jpg


I am sorry I forgot to adjust the FFT length which explains the increased noise floor of the trace at low frequencies. I’ll redo it when time allows. This is the “worst” left channel shown here (XLR and RCA), and we see that resolution is enough for CDA (minimum 16bits), except that spike at 150Hz from RCA. So nothing to worry about.

The Teac VRDS-20 showed reasonable amount of Jitter:

TeacVRDS20_JTest.jpg


The red trace is what is recorded on the test CD (From the digital outputs), it can't be better. The blue trace is from the XLR ouput. We have again low level noise not of real concern (power supply related though).

Let’s have a look at 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:

TeacVRDS20_1kHz_-90.31dBFS_L.jpg


This is a relatively good trace, and it’s disturbed by the low-level noise that I mentioned before.

Starting with this review, and on your request + support (more information here), I am adding an "intersample-overs" test. It intends to identify if the oversampling filter has sufficient headroom to process near clipping signals. Indeed, and because of the oversampling, there might be interpolated data that go above 0dBFS and would saturate (clip) the DAC and therefore the output. This effect is highlighted with the measurements below, and revealed through THD+N measurements 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​
Onkyo C-733
-79.8dB​
-29.4dB​
-21.2dB​
Denon DCD-900NE
-34.2dB​
-30.4dB​
-19.1dB​

I kept some references in the table and will keep the same for other reviews, so you can quickly compare. The results of the Teac VRDS-20 mean the oversampling filter generates clipped signal when presented with specific sine at 0dBFS, so it has no headroom to process them. The Yamaha CD-1 shines here because it's old enough not to have an oversampling filter.

And here are some other measurements:
  • Crosstalk : -116dB (@1kHz)
  • IMD AES : -94.2dB (18kHz+20kHz 1:1 @-5dBFS)
These are very good results for the time.

What else? Oh yes, of course, one of my favorite measurements, the THD vs Frequency at -12dBFS (THD only, over the first 5 harmonics). I already commented that I use it especially to test older R2R architectures as it shows their difficulty to be linear below full scale. Below are measurements of the right channel, overlaid with the previously tested (and near best-in-class) Denon DCD-900NE CD Player:

TeacVRDS20_THDvsFreq_-12dBFS_vsDenon900NE.jpg


Very good! This was the real benefit of going 1bit as it improves linearity (compared to R2R DACs), at the expense of noise created (but that can be pushed beyond 20kHz with noise shaping).

All of these are very good measurements for the time, but I have to mention that JVC, with its proprietary DAC, did better (see the review of the JVC XL-Z335), even in low cost players.


Teac VRDS-20 - Measurements (Digital out)

Are you surprised if I tell you that I did not find any flaws in its digital output? I’ll keep it simple, with what I believe to be the most representative measurement of the digital output quality, and that is a 1kHz sine at -90.31dBFS which shows the 3DC levels of the smallest digital signal in 16bits sign magnitude representation:

TeacVRDS20_1kHz_-90.31dBFS_DigitalOut.jpg


Because this signal forces a regular change of all bits (due to 2’s complement representation around 0), any deviation from the binary content would immediately show here, with such a “fragile” signal. But if you think there are better ways to check the digital output, let me know.

Other than that, this is the standard dashboard of the 1kHz sine @0dBFS (no averaging because I did this measurement way before I decided to go for 32 averages, but it does not change anything here since there's no distortion):

TeacVRDS20_1kHz_-0dBFS_Opti.jpg


This is what is recorded on the CD, so that is perfect digital out, as I see it.


Conclusion

This player and a few others made the “VRDS legend”, and today Esoteric and Teac continue to leverage this legacy. I could not find a mechanical advantage to all of this, and no issue as well. This is completely over-engineered, and I guess those who worked on this player had a lot of fun (I would have had).

No doubt this player knows how to respect what's on a CD. It is also a delight to use, a pleasure even before pressing the play button (which I won’t miss even without my glasses, thanks so much Teac!).

With an external modern DAC, it would be a perfect transport, as I hoped to be able to report. And it delivers.

I hope you enjoyed the review as much as I enjoyed writing it. Let me know how to improve and if you have questions. I can run additional measurements, if you want, but since this player joined me in the main listening room, you’ll have to be patient enough for me to extract it from its current location.

Thank you.

--------
Flo
 
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I really enjoy your reviews, @NTTY . It's fascinating to see all the old "jewellery" being measured properly, especially the THD vs frequency result at -12dBFS, which should be more common (since it likely represents real music energy).
 
thanks for the great test and patience. The internal layout is beautiful, and the construction is excellent. They certainly knew how to do it, in those years some truly fascinating devices came out and, from what we see from your test, they are still performing today. I would say that all that engineering has stood the test of time….
 
I really enjoy your reviews, @NTTY . It's fascinating to see all the old "jewellery" being measured properly, especially the THD vs frequency result at -12dBFS, which should be more common (since it likely represents real music energy).
Thank you!

About this test, a friend of mine asked me what would it look like if I was to extend to 9 harmonics instead of 5 as I show. Maybe that is of interest to others, so here you go.

I put the plot at 1kHz, and with H2 to H5 we get:

TeacVRDS20_THDvsFreq_H2toH5.jpg


You see that the distortion is calculated at -98.6dBr for the Teac and -98.5dBr for the Denon DCD-900NE.

With H2 to H9, we see a small increase of distortion for the two players:

TeacVRDS20_THDvsFreq_H2toH9.jpg


This time, the plot shows -95.7dBr for the Teac and -96.1dBr for the Denon. It's not a big change, and so I think I'll continue with H2 to H5. It also avoids me to update everything I published so far ;)

--------
Flo
 
thanks for the great test and patience. The internal layout is beautiful, and the construction is excellent. They certainly knew how to do it, in those years some truly fascinating devices came out and, from what we see from your test, they are still performing today. I would say that all that engineering has stood the test of time….
Thanks to you too!
Same as you, I thought these devices were fascinating, and I've been wondering for years if they truly performed. Now I know, and that is a lot of fun and learnings too!
--------
Flo
 
It plays only the initial silver disc, no SACD, no USB input, no, no Bluetooth either, sorry :p No digital inputs, too bad, Teac could have made an effort here.
To be fair, being able to use your CD player as a DAC didn't become commonplace until the 2000s. A traditional CD player (unless it is a 1st-gen Sony) has the entire playback chain slaved to the DAC clock, and one with a 1-bit DAC doubly so due to their propensity to jitter. The only interface available at the time was S/P-DIF, which normally requires recoverting the clock on the receiving end... so you pretty much would have needed the player to output a wordclock signal for the source to sync to, and how many digital sources with wordclock sync can you name? It's a feature rarely found outside of studio environments to this day.

A complex D/A architecture: A double mono conversion via two stereo Philips TDA1547 converter which was the first and high-end 1bit conversion of Philips, at the time. It is seconded by the Philips noise shaping (SAA7350) which is necessary for rejection of the noise generated by the decimation to 1bit. This SAA7350 can also perform the final conversion and oversampling, none of which Teac wanted to use from this chip. Indeed, the oversampling and filtering function is given to an NPC SM5840 that runs at 8 times. The Philips couple SAA7350 + TDA1547 was the high-end conversion offer of Philips, and it was named DAC7. Teac therefore deviated as they sourced the oversampling elsewhere. Why make it simple?
This one sounds like it might be taken more or less straight out of the TDA1547 datasheet:
tda1547fig4.png


Out of band attenuation is only 60db (see the blue spikes of images form the test tones at 26.1kHz and 24.1kHz respectively). To be honest, I was disappointed to see that, but I must recon this is similar to previous 4x oversampling filters of the era, especially the one of Philips.
Which it is indeed. Periodic passband ripple is a bit so-so by modern standards at +/-0.02 dB and change but still much better than an early Philips. You can find the datasheet on the interwebs.

Not sure about intersample-overs. I have attached the classic fs/4 +3dBFS test tone that you may want to integrate into your test CD.

You probably already noticed, there is a little power supply leakage (50Hz and harmonics) which, even if without negative consequences at this very low level, I would have preferred not to see (1kHz @0dBFS, XLR out, left and right channels):
I've had a look at the service manual of this unit, and I'd say we've got a bit of a case of Pin 1 Problem going:
vrds20xlrout.png

(I think that's a "2 normal opamps to make a fully differential opamp" circuit. It would have good CMRR there, but before that...)
Note how XLR pin 1 connects to local audio ground which travels all the way back through the mute PCB to the main audio PCB, and who knows where from there. Chassis ground is only used for RF decoupling of audio ground via C719. There would have been a power ground available but for some reason they decided not to use that one at all on the XLR board:
vrds20xlrout2.png

(The boards are also teeming with 100 µF decoupling capacitors on the +/-12 V rails. How to introduce power supply noise into your audio ground 101, although it's mostly a problem for subassemblies connected by cables. Going by the many wire links, I suspect the audio boards are only single-layer - unlike the digital side - so asking for a dedicated power ground may have been asking a bit much. By your pictures, the main audio board seems to have gotten kind of a copper bus bar to keep internal ground resistance low, but that's not helping the stretch of ground between main audio board and XLR board.)

Aside from that this basically is an all-unbalanced construction with a balanced output tacked on, it could be picking up hum from the transformer wiring or whatnot anywhere. (Bruno Putzeys' "G-Word" whitepaper wasn't out for many more years, and as they say hindsight is 20/20.) Overbuilding is one thing, doing it where it counts is another...
 

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Very nice review of this CD player. Deserves the homepage.
The performance is good but I'm not sure if it can be discernible from the +/- $400 DENON drive you tested, if I'm not mistaken.
SQ wise maybe not. Build quality and craftsmanship is in a different universe altogether, though.
 
To be fair, being able to use your CD player as a DAC didn't become commonplace until the 2000s. A traditional CD player (unless it is a 1st-gen Sony) has the entire playback chain slaved to the DAC clock, and one with a 1-bit DAC doubly so due to their propensity to jitter. The only interface available at the time was S/P-DIF, which normally requires recoverting the clock on the receiving end... so you pretty much would have needed the player to output a wordclock signal for the source to sync to, and how many digital sources with wordclock sync can you name? It's a feature rarely found outside of studio environments to this day.
I have the Teac VRDS 25x too and it has a digital input, but was released 6 years later. Maybe over expectations on my side ;)

This one sounds like it might be taken more or less straight out of the TDA1547 datasheet:
View attachment 393609

Indeed, I’ll update my text, thanks!

Which it is indeed. Periodic passband ripple is a bit so-so by modern standards at +/-0.02 dB and change but still much better than an early Philips. You can find the datasheet on the interwebs.
Same, thanks too!

Not sure about intersample-overs. I have attached the classic fs/4 +3dBFS test tone that you may want to integrate into your test CD.
Thank you again, I’ll play with that ;)
 
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I have the 10 (a friend gave it to me) & a Micromega Drive 3.
Same "sound" as a LG or Sony Bluray/SACD player.
 
I had a VRDS10 back in the day for a year or so (a long time back then) and loved it. The inverted platter didn't seem to do any harm and, seeing as some discs weren't *totally* flat at the edges for whatever reason, Anything to help the laser 'read' the end of a disc more easily can't be an issue surely and the little window in the top so one could watch the disc spinning is great eye-candy. I also loved the slick drawer and large illuminated buttons. No idea how far the '10' differed from the '20' though.

The T1 transport wasn't the same inside, however, but was internally 'dressed' to mimic the 10 and 20 superficially, I gather.
 
Thank you again for such an in depth analysis showing clearly your understanding and passion of another "youth dream", your reviews should all be pinned to the front page as they are some of the best ever.
 
@amirm
If you haven't seen this review, sure looks like a good home page candidate as several other members have mentioned in this thread. It is obsolete tech, but a fine example of it and a good touchstone to have with modern measurements.
 
Fantastic to see something you’ve drooled over for 30 years still as good as anything made today,thanks for this off to look for one now.
I was toying with the idea of getting one last year. Looks and ergonomics, can't be beaten.

But too many bad experiences with old CD players put me off. I've had three Technics SLP1200s go bad on me, plus several 'battleships' from other brands.

In the end I bought the new VRDS instead. Not as cool but I can't be arsed running round trying to get repairs done. I figure that new means maximum longevity.

Another great CD player review though.
 
I had a VRDS10 back in the day for a year or so (a long time back then) and loved it. The inverted platter didn't seem to do any harm and, seeing as some discs weren't *totally* flat at the edges for whatever reason, Anything to help the laser 'read' the end of a disc more easily can't be an issue surely and the little window in the top so one could watch the disc spinning is great eye-candy. I also loved the slick drawer and large illuminated buttons. No idea how far the '10' differed from the '20' though.

The T1 transport wasn't the same inside, however, but was internally 'dressed' to mimic the 10 and 20 superficially, I gather.
The 10 had the same D/A architecture and the 10SE adds another noise shaper SAA7350, one per TDA1547. It would be interesting to check if that only made a difference.
 
@amirm
If you haven't seen this review, sure looks like a good home page candidate as several other members have mentioned in this thread. It is obsolete tech, but a fine example of it and a good touchstone to have with modern measurements.
Agree. Some times it is good to look back and see what worked, and why, so our technology path truly goes forward(and does not leave endurable aspects behind). Design and ergonomics are very relevant for users experiences, not just technology. The digitalization of music recording and listening in my lifetime has been exciting. A lot more progress will be seen I am sure.
However, Cd transport and players technology(probable for understandable business reasons) have not kept up with developments. The devices are still too large. DACS, power amplifiers, preamps, speakers have all got smaller and more power full with greater features. As example my cd transport feeds into a much smaller RME-DAC with preamp and eq functionality built in, that feeds active powered Genelec speakers with power amplifier built in.
Many users still value and appreciate physical cd disks ,and vinyl ,as well; it is not all nostalgia. (same situation with digital and film photography, ebooks and printed books)
 
I have also created a 997 Hz 0.999 tone with shaped dither in Audacity now. The noise floor up to a few kHz is about 10 dB below 16 bit flat, and dips another 10 dB lower around 4 kHz (tops going down to about -154 dB in a 16384 FFT). That should be enough to cover some high-performance DACs... in fact, I decided to also include a version with 20 dB lower amplitude (EDIT: plus -60 and -90 dB) since I figured you could run into the limits of your Ultralite first.
(Again, the dither in Foobar2000 has it beat subjectively but this should be better for our purposes.)
 
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