Marantz CD 75 Mk11 - mods

[BDD]

Your CD uses one of the best chips ever produced, the TDA1541-A and is still sought after and used in some very expensive units, for example the SW1X lll @ $5999 who claim the chip to be the most analogue R2R ever.

So mod away and enjoy a huge sonic return. I read and corresponded directly with Lukasz Fikus of Lampizator fame. About 15 years ago I modded my flimsy little Marantz CD40, they can be found unloved and unwanted on ebay for about 30 bucks and are great for mods because of the space inside. Not much there so accommodating a small transformer and a pair of valves is easy.

Basically you come straight off the DAC pins that are signal out and connect them to the grids of an ECC88 or similar. Lukasz' favourite appears to be the 6N6P. And by cutting 2 tracks of the PCB can be rendered NOS (recommended) By doing this you are eliminating lots of noisy circuitry and avoiding the common opamps used for this purpose.

If this all sounds a little daunting it's not and is why I mentioned the CD40. My suggestion is to find one of these cheaply to experiment with. Many players with the TDA chip can be used, like Philips players which can be found in the skip. Marantz/Philips use the same mother board on dozens of different models. Example the Marantz CD40 internals are exactly the same in the CD50 and CD60, just the exterior and chassis differ slightly withe the model 60 having a gold coloured face-plate.

The result of this mod will really delight you and provide you with the confidence to mod the CD75 which you can go all out on if you so choose. My CD40 had bitumen adhesive damping, new quality RCA connectors and solid core wiring. I was so impressed and actually giddy with joy that I built a new power supply for it using an EZ80 rectifier with choke input and Panasonic TSHA 105 degree caps in a separate enclosure connected by an umbilical. I threw out the old power cable, mounted a gland on the back for the new cable and soldered a better one in place. Stunning!

The links I provide take you to the Lampizator site which details with many photos how to go about it. Additional caps around the chip are added by simply soldering them across the underside of the PCB, easy peasy.

Even folks not interested in modding can find tons of useful info here.

http://lampizator.eu/LAMPIZATOR/TDA1...r/TDA1541.html

http://lampizator.eu/LAMPIZATOR/Lampizator.html (find hyperlink to: Lampizator DIY step by step for beginners)

His site needs patience but hang in there, it's worth it.

Wow, great read, thank you! Unfortunately I’ve never used a soldering iron but that is very interesting,


Sent from my iPhone using Tapatalk

[zanash]

there are two or three must do items .............

1 remove the muting transistors...simply snip them off.

like all marantz players and others when you skip tracks or fast forward the laser still reads the disc and plays the accelerated data, so to stop you getting pops clicks etc this audio output is dumped into ground plane. Now this sound great, but the transistor used never quite switch off ..... The result is the ground plane at 0v used as a reference for the other parts of the unit is being modulated by a low level music signal. Not good !

2 replace the 1n00x rectifier diodes. I like shottky 's but hexafreds are good too. the standard diode creates a switching transient each cycle when all four [or more] are working they create a 50hz buzz on the dc rail thats not altogether eliminated by the smoothing caps. Unlike the first mod ..this one may cost you about a £1 a diode.

3 back in the day marantz made some damn fine sounding cd players ..so good were some that they eclipsed the performances of the there flagship units at many times the price. This caused consternation in the bean counters dept...as they wanted people to buy the top units to get best sound. So a tuned "thing " was added to the output to degrade the performance an restore the top machines place. This thing was advertised as HDAM (Hyper Dynamic Amplifier Module)..... With all the marantz units I've modded 57 63 75 5001 6002 plus others that slip my memory ...everyone sounded better by just bypassing the damn thing straight to the output. I hear you cry what about the output caps ..fret not next point !

4 the output cap or dc blockers in the audio output are there to stop any dc getting to thew pre amp . if you know your pre amp has dc blocking caps these can be dispensed with ...Though I suggest you swap them for a low value paper in oil. The difference is truly stunning. the music information lost in the low quality caps fitted would make a grown audiophile cry if he just knew!

5 the abomination of the cheap rca sockets .....rip them out jump from the pcb to the new rca sockets using silver in ptfe. Any rca socket improves on the nasty base metal units fitted ! but if you can push to next gen then your in for a treat.

6 replace all the psu caps I used to use pana fc ...but there are many others available

these six mods are in bang for buck order ...

in sound quality its probably 4,2,5,6,1,3 but its been a few years since I did any commissions. A quick note check suggests I modded about 50 marantz units to a greater or lesser extent with no complaints !


there are many other mods ...many reworking the circuits though my philosophy was that the owner bought the unit as they liked its house sound, so I attempted to retrieve as much music as I could without wholesale changes.

[BDD]

there are two or three must do items .............

1 remove the muting transistors...simply snip them off.

like all marantz players and others when you skip tracks or fast forward the laser still reads the disc and plays the accelerated data, so to stop you getting pops clicks etc this audio output is dumped into ground plane. Now this sound great, but the transistor used never quite switch off ..... The result is the ground plane at 0v used as a reference for the other parts of the unit is being modulated by a low level music signal. Not good !

2 replace the 1n00x rectifier diodes. I like shottky 's but hexafreds are good too. the standard diode creates a switching transient each cycle when all four [or more] are working they create a 50hz buzz on the dc rail thats not altogether eliminated by the smoothing caps. Unlike the first mod ..this one may cost you about a £1 a diode.

3 back in the day marantz made some damn fine sounding cd players ..so good were some that they eclipsed the performances of the there flagship units at many times the price. This caused consternation in the bean counters dept...as they wanted people to buy the top units to get best sound. So a tuned "thing " was added to the output to degrade the performance an restore the top machines place. This thing was advertised as HDAM (Hyper Dynamic Amplifier Module)..... With all the marantz units I've modded 57 63 75 5001 6002 plus others that slip my memory ...everyone sounded better by just bypassing the damn thing straight to the output. I hear you cry what about the output caps ..fret not next point !

4 the output cap or dc blockers in the audio output are there to stop any dc getting to thew pre amp . if you know your pre amp has dc blocking caps these can be dispensed with ...Though I suggest you swap them for a low value paper in oil. The difference is truly stunning. the music information lost in the low quality caps fitted would make a grown audiophile cry if he just knew!

5 the abomination of the cheap rca sockets .....rip them out jump from the pcb to the new rca sockets using silver in ptfe. Any rca socket improves on the nasty base metal units fitted ! but if you can push to next gen then your in for a treat.

6 replace all the psu caps I used to use pana fc ...but there are many others available

these six mods are in bang for buck order ...

in sound quality its probably 4,2,5,6,1,3 but its been a few years since I did any commissions. A quick note check suggests I modded about 50 marantz units to a greater or lesser extent with no complaints !


there are many other mods ...many reworking the circuits though my philosophy was that the owner bought the unit as they liked its house sound, so I attempted to retrieve as much music as I could without wholesale changes.

That’s an awesome rundown from someone who clearly knows their stuff! I’ve not yet received the player, so I will take a bit of listening time to get a feel for it’s sound and how it compares to my other players. Unfortunately I’ve got no prowess with soldering and electronics, but I will keep this info.Appreciate your input.


Sent from my iPhone using Tapatalk

[zanash]

oh yes ..get a service manual worth its weight in gold ....

happy to answer an questions .. drop me a line ! I may even have many of the parts too !

[sailor]

@zanash, good post.