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Marantz CD6003 CD ...high quality machine has pitch control and USB input Marantz is one of the few mainstream hifi manufacturers still making dedicated CD players. In fact, they make quite a few, ranging in price from affordable to very expensive. We take a look at a machine which is somewhere in-between, offering pitch control and a USB input so MP3 and other files can be played. T hese days, most people happily play their CDs through a DVD player, which might be a run-of-themill model or a Blu-ray player. And while the better DVD players do give a reasonable performance when playing CDs, it is certainly not the best sonic result and there are often problems with hum and other interference. It may surprise some readers just how much RF interference can be superimposed on the analog audio and video output of DVD players, particularly on the cheaper models. Sometimes this can be enough to severely interfere with AM and FM radio reception. So inevitably, using a DVD player for CDs means that you can be feeding significant RF signals into the inputs 74  Silicon Chip of your amplifier. That is bad enough but the fact that just about all DVD players are of double-insulated construction and use a switchmode power supply means that there can be significant buzz, hum and other extraneous noises to mar your enjoyment of the music. We investigated these problems fairly thoroughly in the October 2007 issue of SILICON CHIP. One way to circumvent most of the problems of DVD players is to feed the TOSLINK (optical) digital output to the digital input on a home theatre receiver but even there, the results might not be optimum. Better still is to feed the TOSLINK output to a high-quality digital-to-analog converter (DAC) and to that end, we published a high-performance siliconchip.com.au player Review by Leo Simpson DAC in the September to November 2009 issues of SILICON CHIP. This had the added feature of remote control of the volume level. Well, that solves most of the issues to do with sound quality but DVD players still have drawbacks. For example, they often take an age to power up and then recognise that they have loaded a CD. And since they tend to be designed with on-screen display of their features, they don’t do a good job of indicating CD tracks and other functions. And then, when you press PLAY or change tracks, they often have to cogitate about it for a while before responding to your command. All of this came to mind just recently when I decided I siliconchip.com.au Features: •    • • • • • • • • • • Pure high-quality CD Player with MP3, WMA and WAV playback CD-R/RW compatible; CD-text HDAM-SA2 circuitry High-quality D/A conversion (CS4398) Customised audio components Quick replay Pitch control iPod-compatible USB input Coax and optical digital outputs Headphone output with level control Dedicated remote control wanted a new CD player for my study. Having made the decision, I was immediately confronted by the limited choice on offer – just a few well-known brands and at prices considerably higher than even for a good quality Blu-ray player. But I also wanted a high-quality player with the facility of pitch control and that limits choice even further. Sure, there are some reasonably priced “professional” CD players with pitch control but these are geared more to installations in clubs and other similar venues and their audio performance is not up there with the high-quality audiophile brands. Which brought me to the Marantz CD5004. This is their “entry-level” player which does have pitch control, along with the capability to play CD-Rs, and CD-RWs and it will play CD-DA (PCM) alongside MP3 and WMA formatted files at 42, 44.1 and 48kHz sampling frequencies. As well, it has the ability to read music data on MP3s and WMA files as well as text-data encoded CDs. This means that it will show the title of each CD track as it begins playing. It also uses the Cirrus Logic CS4392 DAC chip and the HDAM-SA2, the company’s proprietary Hyper Dynamic Amplifier Modules which were originally developed for their premium Reference Series products. This means that its audio performance should be very respectable. So I checked prices and some on-line reviews, all of which were encouraging. But then I considered the next machine up in the range, the CD6003. It uses a better DAC, the Cirrus Logic CS4398 and it also has a USB socket on the front panel which means that you can plug in a flash drive, iPod or other media source so you can get a really good result when playing these files. In all other respects, it appears quite similar in features to the CD5004. Indeed, all the Marantz CD players have the same styling and general presentation with the differences being mainly confined to the internal circuitry and possibly the ability to play SACD disks. Some of the more up-market models in the range have been specially tweaked by the noted audiophile designer, Ken Ishiwata but I think he has had a hand in the design of most of the Marantz range. He really knows his stuff. So I decided to purchase the Marantz CD6003; just like that, sight unseen. When it was delivered, I wanted to see just how good it was, so I put the CD6003 through its paces on our Audio Precision test gear. And that is how this review came into being. June 2011  75 Inside the Marantz 6003; it’s as complex as we have ever seen in a CD player, with no less than seven PCBs. But beware of that unshielded mains input socket (left top) – it’s a trap for the unwary (if you ever open the case, that is!). Presentation The first aspect of the Marantz CD6003 which impresses is that it is such a substantial machine, in great contrast to the often flimsy cases and ever-diminishing scale of most DVD players. Marantz gear is bulky and solid; there is no other way to say it. And while you can have it in ubiquitous black, I much prefer the silvery sheen shown in the accompanying photos. The front panel looks to be all metal but the central section is an aluminium extrusion while the curved sections on either side are substantial plastic mouldings. Overall dimensions are 435mm wide, 104mm high and 340mm deep, including mounting feet, the front panel headphone knob and rear-mounted RCA phono sockets. Weight is a hefty 6.6kg. The disk drawer is centrally mounted above the dot matrix display. To the left of this are three pushbuttons (Open/ Close, Fast Forward, Fast Reverse), the USB socket and a tiny pushbutton which selects between USB and disk. To the left of those again is a large button for the power switch. To the right of the display panel are another three pushbuttons (Play, Stop & Pause), the 6.5mm headphone socket and the associated small knob for its volume level. 76  Silicon Chip On the rear panel is the 2-pin IEC socket for power, a pair of gold-plated RCA phono sockets for the left and right analog outputs plus another gold-plated RCA socket for the coaxial (SPDIF) digital output, a TOSLINK output socket and a further two RCA sockets for the Marantz proprietary remote control system which allows the CD player to be tied to other Marantz equipment. There is also a small slide switch to select between the player’s infrared remote control and an external control from other Marantz equipment (eg, amplifier or home-theatre receiver). The CD6003 is double-insulated, hence the 2-pin IEC power socket which accepts a standard 3-pin IEC power cord. However, the machine does not use a switchmode power supply. Instead, as becomes apparent when the top cover is removed, it uses a rather elaborate conventional linear power supply with two mains transformers, one of which is tiny, to provide the standby function. Inside, the Marantz appears to be far more complex than any previous CD player we have reviewed. No less than seven PCBs are employed. On the lefthand side of the chassis is the very large power supply board, with umpteen (well, five) regulators fitted with heatsinks. siliconchip.com.au By today’s standards the rear panel of the Marantz 6003 is positively spartan. But it has everything you need: analog out, digital audio out in both coaxial and optical (TOSLINK), provision for a wired remote control and finally, a 2-pin IEC mains socket (which fits the standard 3-pin IEC mains plug but does not have an earth pin because the unit is double insulated). Interestingly, when the unit is on standby, a minuscule red LED on the front panel is alight. Pressing the Power button closes a relay on the power PCB and switches over to the main supply. This extinguishes the red LED and lights up the dot matrix readout which momentarily displays “Power On” then “TOC reading” (indicating that it is attempting to read the table of contents on the CD). If none is present, it then says “No disc”. It then displays “CD” to indicate that it is ready for you to load a CD. Clever little blighter, isn’t it? But it is quicker to respond than a typical DVD player which can seemingly take weeks to rouse itself when it is powered up. Power consumption is quoted as 19W, dropping to a minuscule 300mW in standby mode. Looking back inside the chassis again, we were a little surprised to see that the AC terminals on the IEC power socket were bare of any insulation. Shock, horror! Now I know that the back panel carries the Caution notice “Shock hazard. Do not remove screws” (or in French: “Attention: risque de choc electrique. Ne pas enlever les vis” – nowhere near as threatening) but those terminals should still have some protection from the fingers or tools of a technician who may not be concentrating. Incidentally, the same comments apply to the copper side of the PCB which carries the terminals of the mains transformer. The centrally located PCB carries the NEC microprocessor which controls the transport mechanism, all the play functions and provides the digital outputs. The large PCB on the righthand side of the chassis is the aforementioned HDAM SA2 “Hyper Dynamic Amplifier Modules”. These are operational amplifiers designed with discrete transistors; not any of those “ghastly” op amp ICs! This comes from Marantz’s deliberate appeal to the (often screw-ball) audiophile end of the market which tends to regard even the best op amp ICs with disdain. Not that Marantz is wrong to take this approach since it is definitely possible to get better performance from a discrete design than even the best op amps. Underneath that same PCB is the surface-mount Cirrus Logic CS4398 DAC chip. Presumably, audiophiles will tolerate that; after all, you must have a DAC and if it was a discrete design it would be huge. Also of interest is the separate headphone drive amplifier which appears to be based on a surface-mount dual op amp. siliconchip.com.au This is a so-called “current buffer” which provides a low impedance drive to the headphones. All told, the standard of construction is very good with the double-thickness base plate providing extra rigidity. The CD6003 comes with a large infrared remote control and you might wonder why so many buttons are needed; there are no less than 41! Funnily enough, each one has a function but as we subsequently found, some of those could have been arranged differently. Operating it Using the Marantz CD6003 is a dream compared to the average DVD player, in that it responds much more quickly, as mentioned above. It powers up quickly and if you place a CD on the tray and press the Load/Eject button, it immediately retracts the drawer and then reads the disk’s table of contents, giving a message on the readout “TOC Reading”, followed by the number of tracks and the total playing time. That takes about 10 seconds; a bit slow for a CD player but at least you know that the machine is actually doing something rather than seemingly confused, as seems to happen when a CD is fed into a DVD player. Pressing Play or selecting a track number with the remote control starts playing that track within two seconds. Indeed, anything you do with the remote elicits a response within one or two seconds. By the way, the player can cope with any number of tracks up to 99. Some CD and DVD players are very limited in this respect. If you want to find a particular track on a CD, you just press “AMS” and this plays 10 seconds of music from each track, in succession. When you find the track you want, you just press Play to continue. And of course, you can play the tracks in random fashion, repeat sections, tracks or the whole disk. Or you can program the order, delete some tracks and various other functions which most users will probably ignore. EX playing modes Audiophiles can be very “thingy” about CD players and their various functions and one of the things they have apparently learnt is that the internal microprocessor and display readout and even the digital outputs can degrade the analog audio output on CD players. This is true for some audio equipment and Marantz, seekJune 2011  77 ing to keep these fanatics (er, audiophiles) happy, gives the user the option to turn off the digital outputs and the display, using the Sound Mode button. And interestingly, various reviewers have noted that the sound quality improves noticeably. Well, that is balderdash, to put it politely. Our tests show that it makes not one iota of difference – not even a poofteenth of a percent. In fact, the only difference we could detect when “Audio EX” mode is selected (which kills the digital outputs and the display during playback) was that it prevented some remote control functions, such as selecting the next track with the “next track” button. As already noted, the CD6003 provides pitch control and this can be incremented or decremented in steps of 1% to a maximum of ±12% by pressing the appropriate buttons on the remote. Annoyingly, this kills the digital outputs and these can only be re-enabled by pressing the Reset button to kill the pitch variation. So what if you want to listen to the Marantz with pitch control and via the digital output to a hometheatre receiver? Too bad – Marantz won’t let you and yet it is possible. More annoying still is that the remote has buttons for volume control but you can only have that feature if you have the player linked to a Marantz integrated amplifier. Now this is really silly since the Cirrus CS4398 DAC is set up for digital remote control and would give a higher quality result than when the analog outputs are connected to a Marantz amplifier with its own remote control of volume. While we’re in complaint mode, we should also note that any playback from USB flash drive etc is only available from the analog outputs of the player; so no digital output. So again, if you want to listen to music files on your flash drive via TOSLINK/SPDIF to your home-theatre receiver, you will have to find another way. The good stuff. . . Having got those complaints out of the way, we can talk about the good stuff – and there is plenty of it! One point we have noticed about good-quality CD players is that they typically cite their frequency response as 2Hz to 20kHz but with no tolerance limits. The Marantz CD6003 is the same. And typically, CD test discs do not put out frequencies below 20Hz. So what is the frequency response of the CD6003? To answer this question, we produced our own test CD, with sinewave signals down to 1Hz. And how far down was the response at 1Hz? 0dB. In other words, it is ruler flat down to almost DC. Incredible. At the high end though, it starts to roll off very slightly above 10kHz and is -0.6dB down at 20kHz. We would have preferred considerably less roll-off; say no more than -0.2dB. Where the Marantz CD6003 really shines is in its figures for total harmonic distortion. This is quoted at .002% at 1kHz, a typical CD player spec. We measured around .0015% at 1kHz but we also found that it varied very little from that figure over the whole frequency range from 20Hz to 20kHz. Not that we could easily measure that performance on the Audio Precision because of the necessity to change filter bandwidths (22kHz, 30kHz and 80kHz) depending on the frequency being measured. Not only that but the Marantz does have some residual switching artefacts in its analog outputs at a level of -60dB. 78  Silicon Chip However, we managed to get meaningful harmonic distortion figures by using the averaging mode on the Agilent DSO7304A digital scope to remove high frequency noise and switching artefacts. At lower signal levels of -30dB and below, the Marantz is similarly outstanding. For example, at 1kHz and -30dB, the THD is .04% with a filter bandwidth of 22Hz to 22kHz. At -40dB it degrades to about 0.14%; still an impressive result. Baffling! To say that we were impressed with the harmonic distortion performance is understating the case. It is so good we were baffled. It is better than the specs for the Cirrus CD4398 when handing 16-bit PCM signals. Which raised the question: is Marantz converting the data stream off the disk to 24-bit to get the higher performance which is then possible from this DAC? Possibly but we did not have time to investigate this point. Clearly, in terms of overall distortion performance, this is the best CD player we have tested. Linearity of the DAC was good but not the best we have tested. There is no error down to -80dB but at -90db, it produced -88.5B at 1kHz; an error of +1.5dB. By the way, this measurement was done via the Audio Precision passive audio brickwall filter so no sampling artefacts would have degraded this measurement. We also checked signal-to-noise ratio and channel separation. For S/N ratio we measured -103dB unweighted (22Hz to 22kHz) and 110dB A-weighted. The reason for the improvement with A-weighting is that there is a very low residual level of hum in the outputs; Aweighting filters that out. Separation between channels is quoted as -100dB, with no frequency limits. We measured typically -102dB across the spectrum; reducing slightly to -99dB at 20kHz, an excellent figure. Finally, we decided to test the front panel headphone output which has its own volume control. This has a quoted maximum output level of 18mW into 32-ohm headphones but no other specs. Since we have recently been designing a high-quality stereo headphone amplifier, we just happened to have a suitable set-up for testing into various loads; very convenient. Suffice to say that the headphone amplifier appears to be not quite up to the same very high standard as the rest of the player. But it is still very respectable and has adequate drive for headphones of various impedances and sensitivity. THD is around the .002% mark while the S/N ratio is -104dB; a smidgen better than the main analog outputs. Separation between channels was around -75dB and channel matching about 1dB; mainly a function of resistor tolerances and the miniature ganged volume control. In use? The Marantz performs impeccably. The transport mechanism is very smooth and always quiet – a pleasure to use. And the sound quality is very high – no complaints at all. It is certainly a high-quality machine. Recommended retail price is $899. For further information, contact your hifi retailer or the Australian distributor for Marantz products: Qualifi Pty Ltd, 24 Lionel Road, Mt Waverley, Vic 3149. Phone (03) 8542 1111. Website: www.qualifi.com.au SC siliconchip.com.au