RETRO: Technics SL-P110 (1986) & Sony CDP-690 (1990) CD Players. Did early CD players sound bad?

As we enter the last month of 2021, let's go back in time and consider the question: "Did early CD players sound any good?"

Over the years, I have heard this question asked many times. Typically among audiophiles, the answer almost invariably seems to be that early CD players from the 1980's "suck" (or similar negative expression). Generally, these comments appear without further details to explain the sentiment; as usual in audiophilia, we can find many opinions out there, but few bother with facts to build their case. I haven't seen many contemporary articles or writers discuss this question while looking at objective data to examine performance compared with the hi-res DACs we have these days.

The genesis of this article came about while chatting with my friend linnrd a number of months ago about the sound of DACs, modern devices, and what we grew up with back in the day. Lo and behold, he dug out the two machines you see above from his "archive" of older hardware. They appear to be in excellent condition despite being >30 years old!

Let's have a good look at the performance of these machines, and a listen as well, of course. ;-)

In original boxes:

The Digital Audio Compact Disc (aka Audio CD, "Red Book", 16/44.1 PCM) physical format and players were first introduced in Japan in October 1982. Officially these "laser discs" could hold 74 minutes of music, a total of 650MB data although over the years, we've seen "over-burning" extend that duration up to 80 minutes / 700MB or even a little more. While the 80 minute discs are very common, they are outside the formal "Red Book" standard. The discs are 1.2mm thick, with a diameter of 120mm (4.7"), and a center 15mm hole. This would become the most popular physical format to hold all kinds of digital content from music, to videos, to computer files when we include the high density DVD and Blu-Ray kin.

The first CDs and CD player (Sony's CDP-101) made landfall here in North America in March 1983, finally available after much early publicity. The first CD players had a US$1k price tag and CDs were around US$20 each. Calculated for inflation between 1983 to 2021, that US$1,000 CD player would cost about US$2500 these days.

Despite the prohibitive cost for the average music consumer initially, demand was obviously strong among music lovers such that in 5 years, CD sales overtook vinyl (by 1988). It wasn't until 1991 that they overtook compact cassette sales.

While not the very first generation of CD players, these 2 models we'll be examining in this post came out during the transition time between the introduction of digital audio to the masses and ultimately supplanting analogue media as the primary form of music distribution until Internet downloads/streaming in the new Millennium.

I. About the Technics & Sony players

Let's have a look at the two old CD players above... First up, we have the Technics SL-P110 from circa 1986 (35 years old):

This is the older of the 2 machines we'll be looking at (and listening to). Note the standard front panel with the usual buttons. And the rear is very simple with just the 2 RCA outs and a detachable power cable.

The CD tray is interesting:

The CD sits (right-side-up) within the circular tray and there's a kind of suspension feel on top of that raised central plastic piece. This is a relatively slow CD player which took about 20-30 seconds after inserting a disc for the player to read the table of contents before you can play music.

On the bottom, we see a black "lock" switch which is a handy mechanism when transporting the CD player to prevent movement of the laser read mechanism. Obviously this needs to be unlocked (pushed in) before use.

Based on the information here, the player was priced at US$320 when new back in 1986 (inflation adjusted to US$800 in 2021). The optical pick-up mechanism is called the "SOALP1200". This unit was made in Japan. I'm not sure what the "High Speed Linear Access System" or "Fine Focus System" actually are referring to. Based on some information on other related Technics players of that era, it looks like the internal DAC is the Burr-Brown PCM54HP converter first released in 1985. Although the very first CD players were not quite capable of 16-bits dynamic range, by 1985/1986, we see 16-bit parts like this with rated -82dB/0.008% THD and up to 96dB dynamic range. This would be multibit resistor ladder network technology back then before the advent of bitstream SDM converters became more common (by about 1988/1989).

The other CD player we'll be looking at here is the Sony CDP-690 which came out in 1990 (31 years old):

It has more buttons for direct track access. And we see some text on the front of the CD tray telling us that this device has a "Dual D/A converter system" and "18 bit linear / 8 times oversampling" technology. There's also a headphone jack and volume control on the right side (which sounds fine although I did not measure).

The DAC section consists of 2 x Analog Devices AD1860N chips. The laser head mechanism is the KSS-240A. This CD player's specs sheet listed THD as 0.005%/-86dB with a 95dB dynamic range. It also came with a remote controller.

Note that the AD1860N is an 18-bit DAC chip listed as having 108dB dynamic range, and can perform down to 0.002%/-94dB THD+N depending on the grade of the chip. Its multibit R-2R architecture is "laser trimmed" and "fabricated from silicon chromium thin film". So in principle, this chip can achieve better than 16-bit CD resolution in some ways; 10 years prior to the release of SACD/DVD-A.

While the TosLink interface was designed by Toshiba back in 1983, it took a few years to show up in consumer gear. By 1990, a reasonably priced Sony CD player like this (I haven't seen the MSRP listed so not sure exactly how much Sony wanted for this US$280 MSRP according to Audio magazine October 1990, thanks Orto Fan) featured the digital output.

Non-detachable power cable.

As you can see on the rear, this specific machine was manufactured in September 1990 in Itakura, Japan. Notice the presence of both fixed and variable RCA stereo pairs. I assume the variable output must be adjusted with the remote controller (I don't think linnrd has this any more). For the tests, I'll just use the "fixed" line out which is probably what most users would be doing connecting this to a preamp, integrated, or receiver.

Sony CDP-690 in German Sony catalogue 1991 - that's what the remote controller looked like.

So guys and gals, let's get to it...

II. MEASUREMENTS

In order to measure performance, I obviously need the test signals on an Audio CD. For this, I made my own using some of the signals I have been using over the years on this blog for measuring computer DACs - obviously converted to 16-bits as cleanly as possible using a combination of Adobe Audition and iZotope RX:

There's my test audio CD-R burned using Nero Burning ROM - "Disc At Once" mode, using my LG Blu-Ray writer. Memorex CD-R burn rate at 24X (lowest speed with the CD/DVD/Blu-Ray burner). Over the years, I've updated the test signals on the disc so we're at "Version 4" here. Remember back in the day some audiophiles believed you needed to burn at 1X speed for best sound quality? While some media were not meant to be written to at high speed, assuming one achieves a clean, accurate CD-R burn, and so long as the CD player is able to read the data without errors, there's really no problem with sound quality. Bits Are Bits.

The disc includes signals like the 16/44.1 RightMark, Dunn J-Test, signals for my "Digital Filter Composite", 1kHz sine for THD+N, impulse response, multitones, etc. I'll use this "standard test disc" for future CD players I might measure.

Despite the fact that CD-R's were not available until many years later, these old CD players had no issues reading the burned discs. (The CD-R "Orange Book" specification was released in 1990, but affordable CD burners did not drop below ~$1000 until 1995. I had one of the early HP burners that could write up to 4X, and let's just say reliability was poor and I made many expensive coasters back in those days!)

First, here's a quick look at the 0dBFS 1kHz sine wave coming out of the CD players through the oscilloscope:

Already we can see some differences between the two. The older Technics has a higher voltage output but subtly more channel imbalance with the right channel louder by 0.1dB. Also interesting is that the Technics has a slight phase/temporal shift between the two channels, the left (yellow) being just slightly ahead of the right. We can zoom in for a better look:

With even further zooming in, that temporal shift appears to be approximately 7μs difference between the two channels or ~2.5° at 1kHz. Is that audible? Highly unlikely especially with real music! (I see some discussions on HydrogenAudio awhile back with Arny Krueger on temporal resolution.)

Realize that this interchannel shift will affect frequencies differently, with more impact as the frequency increases and wave period shortens:

With the waveform further expanded as above, we can see that at 20kHz, the temporal shift is about 6.5μs or ~45° interchannel shift and the question of whether this is audible would again be on an audiophile's mind. (At 20kHz where hearing acuity is poor if not absent for essentially all of us adults, I would not worry!)

This interchannel phase shift is not an issue that I have seen with modern CD players and DACs tested over the last decade. Presumably, this is a result of a time-shared decoding mechanism taking turns feeding the data to the two channels.

[If we look at objective testing back in the day, this kind of interchannel phase shift was something that was measured. For example, see the article "Six High Grades" (p. 43-57) by Martin Colloms in the May 1987 edition of Hi-Fi News, specifically the Technics SL-P720 CD player that year based also on the PCM54 but using the higher-grade PCM54KP with 0.0025%/-92dB THD at 0dBFS. They reported a 40° shift at 20kHz for that device.]

Much has been made in the press and among audiophiles that digital filtering has improved significantly over the years and this is the reason some old CD players sound "bad". Let's have a peek at the impulse responses first:

Notice that I've plotted the impulse responses with overlaid left (yellow) and right (blue) channels. Notice that the Technics is polarity inverted (absolute polarity is with left channel upgoing). For more discussions on this, see the article on "absolute polarity/phase". Furthermore the Technics' impulse response isn't a precise symmetrical linear phase appearance, and with the overlay we can again see that the left channel has a slightly advanced temporal shift compared to the right. The Technics' impulse response also looks a little longer with more pre- and post-ringing so we might expect a steeper filter.

In contrast, the Sony CD player demonstrates a clean symmetrical linear phase filter, maintaining "absolute" polarity.

Let's now take a look at the frequency-domain filter characteristics using the "Digital Filter Composite" (DFC) graph (based on the "Reis Test" discussed here):

Above, we have the older Technics. As you can see, it's certainly not that clean. Intermodulation and harmonics evident across the frequencies. There's a little bit of overload behaviour in the 0dBFS white noise. Having said this, it's also not disastrous and there is a decent amount of filtering so it's better than just running NOS IMO.

Moving along to 1990 and the Sony CDP-690:

Well, the 19+20kHz intermodulation distortion is much cleaner with this device. However, the white noise stopband attenuation isn't as strong, nor as clean as the Technics above; that's a bit of a shame! Notice the stronger 24+25kHz imaging artifacts. Yeah, clearly not the best "brick wall", but again I'm not sure I would worry too much when applied to real music.

As an audio "battery" of tests, let's now move on to the 16/44.1 RightMark Test results with these two CD players - we can compare them with some modern DACs playing 16/44.1:

I think this is a beautiful summary of how the technology has advanced between 1986-1990 with the TEAC UD-501 DAC (2013) and onwards to the recent Topping D90SE (2021). Notice how the modern DACs are so similar in performance with extremely low distortions and generally ideal dynamic range of 98dB when reproducing standard 16/44.1! While XLR balanced outputs with the TEAC, RME, and Topping D90SE can help with rejecting noise and interference for hi-res playback, notice that this makes little or no difference with a 16-bit audio test compared to the Topping D10s RCA out.

We can see these results graphed in detail:

These old CD players obviously do not perform as well. The Technics' frequency response has a high frequency accentuation, up to +0.6dB by 15kHz rising from 7kHz which could make this player sound "bright" compared to others. Also notice the 60Hz hum with the Technics with harmonics, there's higher crosstalk especially in the lower frequencies, and more distortion in the IMD+N sweep (we saw the intermodulation distortions in the 19+20kHz tone of the DFC above).

In comparison, the Sony performed better although the frequency response shows a bit of rippling with about a 0.25dB range from 20Hz to 20kHz. (Notice that the Topping D10s also isn't completely flat as a result of the apodizing filter Topping chose for no apparent reason.) The Sony CD player has less hum, better crosstalk and better IMD+N although still just a little worse compared to modern devices.

For another look at that frequency response, we can use REW to confirm (note the Y-axis is a narrow +/-2dB range):

And using that data we can see that there's also a difference in the phase response between the two CD players:

As we saw above in the impulse response, the Technics is inverted, hence the -180° shift for much of the audible frequencies. However, the phase changes significantly through the audible spectrum compared to a relatively flat phase graph for the Sony; that impulse response asymmetry is likely the "tell" that something's going on in the phase. I'll need to look more into this; I assume this is the result of the filter.

Let's now focus on some FFTs to look at distortion/resolution, starting with the 1kHz THD+N. What I'll do is show the 1kHz tone at various output levels: 0/-30/-60/-70/-80/-90dBFS. This will allow us to see how free from distortion the signal appears as we go down in levels towards the 98dB SNR that 16-bit audio allows.

Before showing the results of these CD players, let's put this in context with the performance of a modern sigma-delta DAC like the RME ADI-2 Pro FS which I used for these measurements with XLR loopback, applying 16th-bit dither. Note that because I wanted to see noise level out to 40kHz, this measurement was done with the DAC/ADC at 96kHz which is why you're not seeing the 22.05kHz filter effect as in the CD players:

As you can see, I'm not going to bother with listing the THD(+N) numbers other than at 0dBFS and -30dBFS just so we can have some numerical comparisons (feel free to pixel-peep to see the other numbers if you want!). For highly accurate modern DACs like the RME, notice that harmonic distortion is already easily into the noise floor by -30dBFS.

Here's the Technics SL-P110 CD player from 1986:

We can see the 60Hz hum and harmonics. Notice also the presence of harmonic distortions even down at the -90dBFS output level.

And 4 years later, the Sony CDP-690 from 1990:

Lower 60Hz hum, better control of the 2nd harmonic at low levels compared to the Technics, and harmonic distortions now buried in the noise floor by -80dBFS. As in the RightMark test above, we can appreciate the improvement in resolution when comparing these older CD players with a modern DAC like the RME ADI-2 Pro FS (with AKM AK4490 chip).

Let's end off the distortion section with a look at some multitones (IMD is measured above in the RightMark tests already) - the Triple Tone TD+N and 1/10 Decade Multitone 32.

Here they are for the Technics SL-P110 from 1986 (at 0dBFS):

And the same for the Sony CDP-690 (1990):

The Triple-Tone TD+N is the one I use in my amplifier measurements. The Technics' CD player scored around -80dB and the Sony about -85dB. These are respectable results and many amplifiers will not surpass such TD+N values at 1W into 4Ω. Unless there's something very unusual about the performance of a digital source, it is unlikely to be the limiting factor in most good sound system.

Notice that with the Multitone 32 test, I've included a reading of the peak level across the 16 averages that were captured (red). I received an E-mail asking if averaging smoothed out potential anomalies in the playback. From what I have seen, I don't believe there are any issues and as you can see with the red "peak" level, at no point in the 16 captured values across this 1M-point FFT which amounts to about 80 seconds of data capture were there noise or other distortions exceeding that red level. For both the Technics and Sony, we see at least 75dB and 83dB of dynamic range with no distortion or noise across the audible spectrum respectively.

Back in the 1980's I don't think many digital audiophiles commonly used the word "jitter" in their lexicon as something to be concerned about or to blame for whatever audible blemish they might perceive. Here's the 16-bit J-Test for both vintage CD players:

Notice that the Technics' noise floor is higher than the Sony's. We see the 16-bit jitter modulation signal in both (based on 229Hz 16th-bit pulse) with an accentuation of the proximal sidebands on either side of the 11kHz primary signal with the Sony suggesting some increased data jitter. At most, we're only seeing elevated sidebands up to -110dB below the 11kHz peak; nothing IMO to worry about. Remember folks that the J-Test stimulates jitter anomalies so we can see them - with actual music, the distortions are lower.

For completeness, let's have a look at that TosLink digital output from the Sony CDP-690 fed into a few DACs I have here:

As you can see, the amount of jitter we see/hear in playback from that TosLink output depends on the outboard DAC. The inexpensive SMSL M100 Mk II performed better than the Topping DX3 Pro V2 with lower amplitude sidebands although the noise floor is higher. The RME ADI-2 Pro FS R Black Edition shows us what high quality jitter-reduction circuitry is able to accomplish (they call it SteadyClock) even with an old TosLink input, achieving both minimal jitter and extremely low noise through the XLR balanced output.

Over the years, I have not seen/heard jitter to be a problem with straight CD playback. It was only an "issue" when we started using the S/PDIF interface (either Coax or optical TosLink) which is prone to jitter due to the need for clock recovery to synchronize the data. Ironically, I think audiophilia created the "jitter" issue among home users by separating the transport from the DAC via that S/PDIF connection, and subsequently the cottage industry went to work to save us from the issue by selling us magic digital cables, re-clockers, de-crapifiers, etc. These days, asynchronous interfaces like USB and ethernet are simply better with lower (or even essentially absent) jitter.

This 1990 Sony CD player is the oldest device with a TosLink out I've ever tried. It's good to see the LED transmission module still works well after 30 years and there were no compatibility issues with the different DACs.

III. Subjective

Guys and gals, I don't think there's need to spend too much time here, in part because I've also made some hi-res "AMPT" recordings so you can download and listen for yourselves further down!

I did however have a listen to these CD players in my sound room with a compilation disc I made years ago consisting of tracks from The Beatles, Leonard Cohen, Daft Punk, Di Meola/McLaughin/de Lucia and Rodrigo y Gabriela.

Also, I popped in Taylor Swift's "new" Red (Taylor's Version) (2021, DR7) to get a taste of the latest modern pop production sound. I enjoyed her "All Too Well [10 Minute Version]" which has just become the longest (in duration) #1 song on the Billboard Top 100, toppling Don McLean's "American Pie" (1972, 8 minutes 32 seconds) after 49 years!

To be more sensitive while listening for differences, I tried some A/B listening one afternoon/evening as well. I compared the DIY Raspberry Pi 3B+ "Touch" streamer to RME ADI-2 Pro FS R Black Edition DAC vs. one or the other CD player. I just connected them to different RCA inputs of the Yamaha RX-V781 in "Pure Direct" mode, flipping back and forth remotely for A/Bing. Since the RME has its own volume control, I was able to match output levels to around 0.25dB.

As an example, in the image above, we see both CD player and Pi streamer playing the same album, A Maze Of Grace (1997, DR7) from the Christian contemporary group Avalon. I've always enjoyed the track "Adonai" although this is one of those IMO overly-bright sounding tracks, so I wanted to check if the Technics made it even more harsh sounding. Yeah, I think so. Flipping quickly between the RME DAC and the Technics CDP, the RME sounded a bit more refined and less brittle in the high end, more substantial midrange, and just overall more pleasant. Having said this, I'm certainly not suggesting that the differences were "night and day"! After a few A/B flips, getting a little fatigued, it was easy to get lost not being sure which is which. IMO, the sound difference is nothing like the variation between speakers, headphones, or even amplifiers.

Admittedly, I performed the measurements prior to listening to these players so maybe I thought I heard some harshness with the Technics SL-P110 knowing objectively that it has a slightly tipped up treble. Also, turning up the amp volume, I could hear the 60Hz hum from the Technics. Otherwise, I still enjoyed the music and didn't think there were any issues with deep bass, full soundstage, and good resolution.

In a similar way, I used Sarah McLachlan's Fumbling Towards Ecstasy (1993, DR10) to compare the Sony CDP-690 to the RME. I heard maybe a little better shimmering of the cymbals on "Wait" and a touch more spaciousness on "Possession" using the RME DAC. Again, these are subtle and not in any way obvious despite the decades of development in digital audio and improvements in elements like the digital filter!

By the way, I like the simple vocal/piano "Possession [Remix]" version found in some of the later releases of this album, and there's also the "Rabbit in the Moon" dance remix which is very cool as well. Honestly, I had no concerns with the sound of the Sony CDP-690 in my room and would hate to be put to a blind test in light of such minuscule differences.

So, I'll leave it to you. Here are the AMPT (24/96) recordings for your listening and comparison pleasure direct from the RCA analogue outputs to the RME ADI-2 Pro FS:

Technics SL-P110 (1986) AMPT Recording

Sony CDP-690 (1990) AMPT Recording

Feel free to compare to other DACs (here and here for example). Let me know what you hear. I'm curious especially if you think that the phase shift between the left/right channels with the Technics is audible (yes, this temporal anomaly is captured in the recording).

IV. Summary

It's good to have a look at these earlier CD players, examining in hindsight how the technology has evolved over the years. While clearly some characteristics like filtering and low-level resolution have improved, I think we need to be careful about dramatic declarations around audible sound quality. Since 1986-1990 when these particular CD players were introduced, of course there have been numerous generations of products. It should be no surprise that performance has evolved with gradual improvements, objectively demonstrable, leading to the affordable high-resolution DACs we enjoy these days.

The good 'ol days with physical buttons galore. ;-)

So, did old CD players (from the '80s and early '90s) sound bad? Nope, I don't think so.

It's always dangerous to generalize since I'm sure there are some very cheap, poorly designed, or just plain broken stuff out there. At least as far as I can tell, by 1986-1990 with these good quality mainstream Japanese players, CD playback sounded great already and I think it's the usual factors - room acoustics, speakers, amplifier quality, well-mastered music - that truly determine the perceived fidelity of a good component audio system.

Humans, being what we are, will own all kinds of opinions. On the Internet and Fora, you will no doubt also see comments by "anti-CD" people (discussed here for example) who disliked CD sound supposedly since the beginning with early players, sometimes wearing this opinion as a badge of honor; a "special" kind of audiophile. As I have discussed in the past, vinyl can certainly sound good but please let's not idealize LPs as some model of high fidelity (it's simply not). I think it's reasonable to just be mindful that some folks are prone to dramatics whether it's comparing digital gear or digital vs. analogue. Alternatively, maybe some folks just want to impress others or sell them something. ;-)

The results here I think just adds to the body of evidence (including our blind test from 2019) that there's no need to get too obsessed about the slight differences between decent digital source devices (at least with 16/44.1 playback, and the need for hi-res has always been questionable). Stuff like jitter was never IMO really an issue (as usual, have a listen to the demo). Digital filters play a role but already by 1986, while clearly not as clean as today, IMO the filter was still better than listening without filtering (ie. NOS, seriously folks, don't worry about the impulse pre/post-ringing some people also seem to get worked up around).

Of the two CD players, I think the sound from the Technics SL-P110 is an example of slight upper frequency harshness, but even there, one has to be quite discriminating to tell the difference blinded when compared to modern hi-res DACs. Furthermore, depending on the idiosyncrasies of one's room and speakers, the frequency response accentuation might sound good if one has excess high-frequency roll-off.

Practically, I think even for "high end" systems, a used, inexpensive older CD player like these (often found at used/thrift stores for pennies on the dollar) will be just fine. In particular, I think the Sony CDP-690 is quite good, an example of the classic multibit R-2R DAC (not that I think there's any point focusing on the underlying technology as if this is a huge determinant of fidelity!). As usual, when buying used older equipment, check that the physical transport mechanism is in good shape. I trust this is consistent with my general perspective that one does not need to spend much money on digital players. 

Thanks again linnrd for letting me test out stuff from the "physical archives". Given how well these players worked, you've certainly kept them in great condition! ;-)

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Happy December everyone!

I'm not seeing much happening this week in the audio hardware world. I guess whatever products are being aimed at the Christmas shopper have already been advertised and shipped to a significant extent by now although we might see more "shopping guide" type fluff on audiophile sites.

This weekend, I'll be checking out The Beatles: Get Back documentary (Disney+):

I love the Beatles, although 7.8 hours across 3 parts will need to be done in a few sittings I think, with lots of popcorn, beverage and breaks. Very impressive footage based on what I've seen so far!

I am hoping that the Omicron COVID-19 variant won't be as scary as the news media is making it out to be. I'm still aching to catch some photons by making it out to Honolulu over the New Years ;-).

At some point, it would be a blessing to have this virus mutate into something that's highly transmissible (overtakes a more dangerous strain like Delta) but of low virulence (ie. few end up in hospital or die), beginning to turn this coronavirus back into a form of "bad cold". Will need to keep an eye on the numbers out of southern Africa. Perhaps only then with a combination of the vaccines already delivered for a substantial percentage of the population, plus natural immunity from those exposed, we'll finally be "done" with this pandemic. Seems like that's also the only way out from a perpetual churn of getting "boosters" to the whole population every few months which also sounds ridiculous. Let's see if Omicron could be a step in the right direction, and humanity catches a break from the virus in 2022.

Take care folks. I hope you're enjoying the music.

Addendum: December 9, 2021

Included the phase graph above. Thanks for the reminder thewas at ASR.