Saturday, July 31, 2010

Marantz CD6003 modification

I managed to acquire an almost mint condition pre-owned Marantz CD6003 recently. Brand new, this CD player is priced at a modest SGD 388 in Singapore, pricing it in the mid-entry level category.

Once upon a time, long long ago, a CD player of this build and sonic quality would cost at least two to three times the retail price of the CD6003. It's nice to see that the price of quality kit like this has come down over the years.

The CD6003 is quite a handsome player and has good build and heft (slightly over 5 kg). The chassis is fairly rigid with a double layered bottom plate and compared to the SA8003, the immediate giveaway in cost cutting is an extremely flimsy CD tray.

Based on the Cirrus Logic CS4398 DAC and Marantz's proprietary HDAM SA2 analog output stage, the CD6003 packs fairly advanced technology for a player of its modest price.

An IEC socket permits you to play around with after market AC cords if you wish.

Popping the hood yields no surprises, with three circuit boards connected by ribbon connectors. The left board is the power supply section with two separate power supplies. one linear and the other switched mode.

The center board controls the transport and the right board contains the DAC (hidden on the underside of the board) and analog output stage. The analog output stage is Marantz's HDAM SA2 circuit and is basically a discrete transistor circuit. 

There is a lot of information out there on modding Marantz CD players, the most famous being the infamous CD63/67 modification thread on DIYaudio. Limited this time by lack of a service manual, I decided to just do a few tweaks that were easy and bang for the buck. The CD6003 is intended for use in my office and I did not wish to spend too much time or expense in this project. Besides, if I wanted a reference class CD player, I would have bought a better one to begin with.

Over the years in modifying Marantz CD players, the most dramatic difference in my humble opinion comes from upgrading the DC blocking capacitors. So far, the Marantz players I have handled (63, 17MkIII and now the 6003) use a pair of Elna electrolytic caps back to back to make them non polarised. Usually I bypass them completely after determining that there is no DC offset. Unfortunately this time around, DC offset was quite high at 150mv. I don't usually try film capacitors in this location due to space limitations and the high value needed to avoid bass roll off. So, a pair of 6.3V 22 uF Rubycon Blackgate HQ NX non polarised caps were used to replace the existing 4 Elna Silmic caps used. I also usually remove the muting transistors, but decided to leave them alone this time.

Next, came the digital power supply to the CS4398 DAC. The local decoupling cap was changed from a 100 uF Koshin cap to a Sanyo Oscon cap of the same value. The stock circuit bypasses this cap with a small ceramic cap which I left in circuit. I have very good experience with the Oscon in digital power supply decoupling and cathode resistor bypass applications.

I also added some blu tack on the oscillator crystal, the CD transport bridge and the transport frame (not visible in my pictures).

Total cost of the modifications is less than SGD 20.

Extended listening was done to the modded and unmodded player on my main system which consists of  Focal Micro Utopia BE speakers driven by the Cary SLI-80 Signature Special Edition. Comparisons were also made with my usual CD player, the CEC TL-51XR.

In stock form, the 6003 is a competent player that punches well above its price class. It's sins are one more of omission. It is a smooth sounding player with decent bass and high frequency sparkle. Its failings in comparison to more accomplished machines are a lack of solidity, and somewhat homogeneous presentation of detail. 

Observations made using my regular test tracks :-

1. Eva Cassidy - Fields of Gold : Compared to the CEC, Eva's voice was somewhat vague in imaging. Her accompanying guitar was somewhat lacking in bite and body and blended into the background. There was an obvious lack of retrieval of ambience from the recording - the acoustic space from this track which was recorded live at The Blues Alley was not well conveyed.

2. Patricia Barber - Summer Samba. The percussion work about a minute into the track did not have the shimmer and air of the CEC. The fine detail in the high hats etc were not well separated and sounded somewhat lost in the mix. Piano notes were not realistic as they sounded a bit plasticky and lightweight.

3. Rebecca Pidgeon - Spanish Harlem. The sound of the shakers was quite similar. On the CEC, each shake was distinct and varying in image height and volume.

After modification and about 20 hours of burn in.

1. Eva Cassidy - Fields of Gold : The center vocal image is dead center. There is an overall increase in resolution with each pluck of the guitar being more distinct. Vocals are more distinct and Eva's voice has distinct varying shares of texture.

2. Patricia Barber - Summer Samba. The fine details in the high hats were better separated and the shimmer and air improved. Piano notes become a little more solid and more stable in pitch.

3. Rebecca Pidgeon - Spanish Harlem. The differences in each movement of the shaker was more easily discernible.

In summary, the modifications improved midrange transparency and  ambience retrieval. Vocals seemed to benefit the most, with the homogeneous nature of the stock player being significantly improved. Although there was increase in weight and solidity of the upper mid bass, the low bass notes did not seem to be improved by the modifications.

The subjective quality of the player was significantly improved but still quite far from the CEC. In separate listening sessions, the differences were quite liveable, but instant A/B comparisons showed that even modded, the 6003 was no CEC slayer.

Lastly, I tried a trio of Finite Element's Ceraball footers under the 6003. The improvement in quality was shockingly good and at least equal to the cap modifications. If we consider the 6003 in stock form to be about 40 % of the quality of the CEC (not bad if you consider that the CEC is more than 4x the cost of the 6003), the cap mods and Ceraball would bring the 6003 to around 60 % of the quality of the CEC.


horchai said...

How abt an auricap tweak across the iec terminals? It was a popular tweak once in the past. May be applicable.

Eric said...

Yes, maybe it is worth a shot. If installed directly across the IEC terminals, it will be constantly drawing current. It should have a resistor soldered across in parallel to discharge the capacitor when the player is off.

For safety reasons, a capacitor used in this manner across the mains should be an x rated cap.

Eric said...
This comment has been removed by the author.
horchai said...

Recommended values seem to be a 0.47uf, heatshrinked as additional measure against explosion and spraying of its contents everwhere.

Do u need any crystals? i've some med sized citrine and amethyst all belonged to the quartz family. Used for its piezoelectric properties.

Anonymous said...

Bro, I have a CD5003 model. Can it be modded? Will pay if you have the time. Thanks!


Eric said...

Hi Andy,

Sure, the CD5003 can be modded on the same lines as the CD6003. I have not seen the insides of the CD5003 but I'm quite sure that the analog output stage would be the same. As for the clean up of the digital power supply line, this is a generic mod that applies to most CD players.

Unfortunately, I do not do modifications for fees but check around local forums, there are plenty of people / companies that offer modification services.

Anonymous said...

Ok, Thank you for your prompt reply. I'm still clueless at the technology you're talking here and I'm not quite sure how to proceed from here.

Anonymous said...

Hmm..My CD6003 muting transistor is burnt, can I simply remove it?

Hamid said...

marantz wasnt mature enough to do this mod...

Eric said...

It is quite rare for the muting transistors to burn out. If you are sure that is the only problem, then yes, you can just remove them without further modifications.

Anonymous said...

Additional problem now. Without the muting transistors but it only work for a while. Found 1 C3200 and 1 A1268 shorted.

COOLDUDE said...

hi ,

need your help . My Marantz CD6003 (out of warranty) needs a spindle motor replacement . Did a lot of googling and tried a lot of stuff ...before arriving at this inference .

Cleaned the lens . CD spins without the spindle motor at the top . So the other motor seems to be working fine . When i remove the spindle motor and place it again works for some time ...and goes off in case I replace the cd or power off and power on . I have to rotate the CD manually to get the started those fans .

Can u suggest where can i find a spindle motor attached to a platter which will fit in my CD 6003 . Do they use standard ones or is it proprietary ...

from the image that you have on your blog I referring to the part which is attached on a black plate(platter) with two screws and which pulls the cd upwards ...I am new to this that I guess is the spindle motor ? Pls confirm this also

Eric said...

Hi Cooldude,

It would be better for you to bring it in for service. I've never seen a failed spindle motor before (maybe I am lucky). Usually the problems trace back to a bad lens or a problem in the servo board.

BS Lee said...

Just acquired a used CD6003 in near mint condition. I bought it purely for the USB feature. This is my 2nd Marantz after I've sold off my mint CD63 KI many years ago. After listening for quite a while to establish its stock performance, I set out to mod the following on the PSU and Audio Output PCB. Nothing done to the DSP board. That one maybe later on and most probably unlikely.
1. Change all the smaller electrolytic caps to Panasonic FC low impedance type of same capacitance value.
2. Replace all electrolytic caps on the audio board to Nichicon Fine Gold and Panasonic FC.Fine Gold was at the DAC supply lines.
3. Dynamat damping on the chassis cover.
4. I compared the Marantz DAC schematic to factory CS4398 datasheet and found 1 cap (Vref supply filter cap) to be under specified. I up rated from 33uF to 100uF and 47uF respectively.
Done. After some hours of running in, the performance was far superior than before in numerous areas.
Bass lines are tighter, better defined, metallic instruments sound more refined, richer and purer. Cymbals are clearer and not splashy or crashing as previously. The whole music performance is of a very different character that is very satisfying. Other notable points is the timing and pace is a little faster and more cohesive. Layering and space between vocals and music apparently a more satisfying experience. Its now more musical and satisfying to my previous Rotel RCD971 with Kwak Clock.

Eric Teh said...

Thanks for your comments. This is useful information for those modding their CD6003.

BS Lee said...

AB Compared CD6003 with a dated Marantz CD63KI stock. Both connected separately to Preamp input and switchable AB to compare with same CD.
63KI was very good but falls short in vivid presentation, 6003 was far more forward, lively and better defined everywhere. CD63 sounded laid back, smaller dimension and rather relaxed. CD6003 would make you sit up and become attentive immediately.
Then a simple opamp swap on the CD63 with LM6172 chip, huge improvement and nearer to CD6003 but still not there. It lacked by a small degree of space, dimension and refinement. Its been quite a refresher and interesting exercise after left off digital mods for quite some years.
Meanwhile, changed a few more critical filter caps to FC types on the DSP board. Perceived another step of improvement. More solid performance heard.