modding a Marantz CD75 MKII SE

[tuyen]

Below post from a post back in 2005 on diyaudio forum. Link here: http://www.diyaudio.com/forums/digital-source/52357-mod-cheap-marantz-player-into-great-top-load-transport-cdm1-mkii-long.html

mod cheap marantz player into great top load transport (cdm1 mkII) Long.
Wanted to share my experience with modding an old Marantz CD75 MKII SE into a really nice top loading transport and comparing it to some 'high end' commercial units.

I apologise for the length of the text. I am not a writer and just want to share some of the enjoyment i have got from this player.

The Marantz was made in Belgium and contains the CDM1 MKII transport and TDA1541 dac. Had my own double crown TDA1541 non os etc.etc. dac so only wanted to use as a transport.

Some time ago i bought the abovementioned player for all of $20 and thought i would play around with using it as a top loader.

Rest of system was Alon 4 speakers modified to be close to current circe, very musical 845 monoblocks, cryo silver and copper flat ribbon cables, non oversampling TDA1541 dac with pot.

Stock compared as a transport to my Teac P500 the teac killed it in every possible way.

I unscrewed and threw away the top of the marantz and threw out the drawer mechanism and the large piece of noisy plastic holding on the puck.

Pressed play and the puck flew up in the air since it now had no stabiliser.

Added a 20c coin with blue tac to the puck and it worked. Substantial improvement compared to original. Added more coins. As coins were added increasing weight of puck sound became slower, richer with better bass but losing top end and sounding pretty sick. Best balance seemed to be 2 20c coins.

Next mod was to unscrew the feet of the base of the player and blu tac it to a 30 mil piece of mdf with some shun mook feet underneath.

Now the modded marantz killed the P500. Far bigger soundstage, more bloom, deeper bass, richer tone, lovely decay etc.

A friend of mine brought over his Jadis second from the top of the line transport JD2 (i think) at $18000 Aussie dollars retail with another couple of friends.

Everyone who was there was amazed to discover that the old marantz was quite a bit better overall than the Jadis. Jadis uses the CDM12. something mechanism, weights a ton, is a toploader and comes in this very garrish polished stainless steel chassis. The Jadis had a bigger soundstage and deeper base extension but the marantz had lovely instrument timber, really nice flow to the music, excellent decay and beautiful midrange and top end. Voices in particular were beautiful.

Friend who before this thought Jadis was best transport on earth (having compared it to cec tl1 and sony 777 (the big top loading similar to SCD1 one) sold it a week later for a few thousand dollars. He is after a CDM1 MKII at the moment.

We opened up his Jadis and had a look at the plastic CDM12 mechanism and then compared it to the CDM1 MKII in the marantz. He said that it was like the Jadis was mercedes with skoda engine versus the marantz which looked like a VW beetle with a Ferrari engine.

At this stage i sold my P500 and was pretty excited about doing more work to the marantz and comparing it other transports in some other systems.

I bought a CEC TL51 (Z i think) which has the same basic belt drive mechanism as the 27000 us dollar burmester and figured i would do some power supply upgrades, add a clock etc having read rave reviews of the Burmester in The absolute sound. It sounded lovely but a little sterile so i kept it on repeat for a couple of weeks. I also took it apart and added some harmonix dots, some paper masking tape for basic damping to parts of the chassis (too much damping killed the sound) and stretched the belt a little which made the sound larger with more bloom and richness.

Compared to the Marantz with all the mods as above the CEC was unfortunately better. Made the marantz sound grainy and like it had no bass. The CEC had a lovely liquid presentation which was addictive.

CEC was then sold as i was short of cash so i decided to do some more mods to the marantz.

I took the entire player apart and diisconnected all the digital, drawer mechanism and variable volume op amp sections of the player to provide a better supply to the basic mechanism.

I threw away the rest of the plastic casing leaving just the CD player board, LCD display and transport mechanism and mounted these all on blu tac for decoupling to about 6 inches of mdf wood (i inch sheets with blu tack in between to stick them together.

Really massive improvement this time. Grain went away, Soundstage grew, bass got much better with regard to extension and impact and sound became more detailed and refined.

I then changed the small figure 8 power cord for a 3 pin iec connector and a diy power cord (Chris Van Evers design). Again big improvements. More again of what i mentioned above.

Next mod was to put 2 .47mfd caps (wondercap ultima as did not have the auricaps which were recommended) across the plus and negative rails where the power cord meets the pcb. This was mentioned on a previous thread here where the author said it improved the sound by cleaning up the junk coming into the power supply of cheaper players.

This made a small improvement in clarity and detail.

Took the now very ugly and heavy player to a friends place and compared it to the CEC which he was thinking of buying. His system is really lovely and includes proac response 4 speakers which have a huge but refined sound thanks to those lovely ATC drivers.

The CEC had previously killed his Meridian 508 which he then sold on ebay before borrowing the CEC).

The sound he was getting was really great with the CEC so i thought the marantz would get smoked.

I was wrong big time. The modified marantz was an amazing improvement over the CEC. Everyone in the room was looking at each other in amazement. difference in sound was staggering. The soundstage height which before was about the height of the speakers (5.5 feet) extended to the ceiling and touched each side wall of the room. Bass went down what felt like another octave with real grip and the timber of instruments was stunning.

Another really nice thing about the marantz was that all the instruments had real body and were 3 dimensional. The sound which was obviously very good CD sound before sounded very similar to a turntable. Not as good as the current state of the art but very close to the sound of a Linn Sondek LP 12 with some but not all of the mods. It was very hard to change CD's as we kept just getting drawn into the music.

My friend did not buy the CEC.

Last stop was another friends home who has some spectacular 3 way speakers build by a speaker genius in Melbourne who used to sell commercial speakers under the Muratori label.

The comparison player was the Teac P10 and is about 10 years old. It was one under the P2S which was Teacs ultra expensive VRDS transport. They sell in Australia now for around $2500 second hand and are still very highly regarded.

Anyway, the sound our friend gets with this combination has always been fantastic and very musical.

This was a pretty close call. The TEAC was more refined, with greater detail and quite a bit more life and dynamics. It also had a bigger sound, the marantz not producing much in the way of sound past the width of the boxes.

As the marantz warmed up it was getting better and better I assume as all the old caps etc charged up.

I took this opportunity to clean the laser mechanism with a cotton bud and a little windex (was going to try the drop of soap suggestion but was worried about soap film being left on the laser).

This was a really big improvement to the sound. Now it was far more dynamic, detailed, better bass and a far bigger soundstage.

We went back to the P10 a few time but kept returning to the modified marantz. My friend kept saying 'where has the bass gone" when listening to the p10. The P10 for all its lovely virtues also sounded a little edgy and thin which left us in no doubt that we were listening to CD.

Again the 3 of us present thought that the modded marantz just sounded like good vinyl, 1 person saying that it reminded him of mastertape type sound.

We spent the next couple of hours just putting on CD after CD and revelling in the music.

Our friend who owned the sytem commented that he heard little details that he had not heard on his discs before and that the sound was just so natural. Nobody was pulling apart the sound. We were all concentrating on the music which is what for me this hobby is all about.

Needless to say, he is now looking for a player to modify which contains the CDM1 MkII.

One final note. We tried to play a Jimmy Webb CD which was really badly damaged. On the VRDS it was skipping, making funny sounds and then would not play at all or index tracks. On the marantz it played like it was a brand new CD!

[tuyen]

I did the removal of the plastic drawer mechanism and the weight on the puck mod on my Marantz CD75 MKII SE and indeed it does sound very good!

I will continue to follow his mods to see good this unit can get.  It uses the 7220B chip which is good news as I can also take the I2S signals from it into the DAC.   I wonder how close it can get to the CD94  (CDM1  vs CDM1-MKII).

Will upload some photos soon.