Hi All...
I picked up a Marantz CD75 from a pawn shop for the equivilant of $30 today, it proclaims to be a 'Digital Monitoring CD Player' (i'm guessing that means it has a digital output on the back-plate), and i've opened it up, and its full of Elna Cerafines, and has a Philips TDA1541 as its DAC (with a 'Z-Filter')...
...It looks like the previous owner might've modded it a little, the original timing crystal is still there, but there is a small inverted circuit board in between the crystal and the DAC, that looks to have been installed a little haphazardly...
Sounds pretty good... once its settled in a little, i'll compare it to my CD850... but just wondering if anyone here knows its vintage etc (as there appears to be nothing on search engines)
Thanks 🙂
I picked up a Marantz CD75 from a pawn shop for the equivilant of $30 today, it proclaims to be a 'Digital Monitoring CD Player' (i'm guessing that means it has a digital output on the back-plate), and i've opened it up, and its full of Elna Cerafines, and has a Philips TDA1541 as its DAC (with a 'Z-Filter')...
...It looks like the previous owner might've modded it a little, the original timing crystal is still there, but there is a small inverted circuit board in between the crystal and the DAC, that looks to have been installed a little haphazardly...
Sounds pretty good... once its settled in a little, i'll compare it to my CD850... but just wondering if anyone here knows its vintage etc (as there appears to be nothing on search engines)
Thanks 🙂
it also looks like someone has had a go at re-doing the caps...
Dial-Up Warning - Large Image!! so you can see the cerafines, and that green square I was reffering to in my last post...
Any ideas or help in working out what that green thing is will be majorly appreciated
Thanks 🙂
Dial-Up Warning - Large Image!! so you can see the cerafines, and that green square I was reffering to in my last post...
Any ideas or help in working out what that green thing is will be majorly appreciated
Thanks 🙂
Looks a lot like a CD650 main pcb. My guess is that the small pcb comes from the factory. Think that because of the markings on it.
The xtal next to the 7220 is connected to that chip, not to the dac.
Your 'modification' is connected to pen 23 of the 7220, which is the mute coming from the MAB to the dig filter. My guess it is a last minute mod because they could not get the correct MAB..
My 650 had a similar pcb, but that even contained the mab and some logic stuff on a bigger separate pcb. Just because they did not get the controller right first time (or using older versions still in stock, or ...). I got a MAB from a later cd650 version and it was a nice drop-in for the complete pcb!
So you can still do a clock-mod😀 Next time you take a pic like that, open the drawer. Then we can also see the cdm used, my guess is a dark-green cdm2.
Send me a pm for the 650 schematics, you can get a good way with those (but i can see small differences, near connector to front pcb)
> wat een kl*tedag vandaag! < (offtopic, we had a bad day)
The xtal next to the 7220 is connected to that chip, not to the dac.
Your 'modification' is connected to pen 23 of the 7220, which is the mute coming from the MAB to the dig filter. My guess it is a last minute mod because they could not get the correct MAB..
My 650 had a similar pcb, but that even contained the mab and some logic stuff on a bigger separate pcb. Just because they did not get the controller right first time (or using older versions still in stock, or ...). I got a MAB from a later cd650 version and it was a nice drop-in for the complete pcb!
So you can still do a clock-mod😀 Next time you take a pic like that, open the drawer. Then we can also see the cdm used, my guess is a dark-green cdm2.
Send me a pm for the 650 schematics, you can get a good way with those (but i can see small differences, near connector to front pcb)
> wat een kl*tedag vandaag! < (offtopic, we had a bad day)
I've been use this CD player for many years till now, good transport, it can read almost anything. Hard to find a remote. i use it connect to my dac.
from the pic your have been mod. OPamp it was LM833.
cheer
from the pic your have been mod. OPamp it was LM833.
cheer
Quite sure it uses CDM2
Quite a nice machine, lots of mods possible. If it uses LM833 replace those quickly, even 5532 is far better sounding. Diodes also make a big difference.
Any RC5 remote should operate the player...
Guillaume
Quite a nice machine, lots of mods possible. If it uses LM833 replace those quickly, even 5532 is far better sounding. Diodes also make a big difference.
Any RC5 remote should operate the player...
Guillaume
Re: Quite sure it uses CDM2
Also, I would have agreed with you about the remote control, seeing that Philips and Marantz were for quite a while the same company - but my Marantz CD63SE remote (which works my Philips CD850 perfectly) doesn't work at all on this CD75 (I have made sure that the remote switch at the back is set to internal)
Maybe the remote sensor is dead...
Thanks for the replies 🙂
This player has JRC op-amps in (although if my memory serves correctly, JRC copy other manufacturers ICs... so this could be right on the money... If the 5532s are a straight swap, then I might do that at the weekend as I have a couple spare right now...tubenut said:
Also, I would have agreed with you about the remote control, seeing that Philips and Marantz were for quite a while the same company - but my Marantz CD63SE remote (which works my Philips CD850 perfectly) doesn't work at all on this CD75 (I have made sure that the remote switch at the back is set to internal)
Maybe the remote sensor is dead...
Thanks for the replies 🙂
Maybe sensor is dead
I have not used other remotes with a CD75 but it is from the same era as some other philips units like cd471 and that remote works many players...
What JRC op amps does it use? The NJM2114 is a copy/equivalent of the 5532 and Marantz preferred it, using it as an SE upgrade on things like the CD50 that had 5532 as standard. I went through many dual op amps in a QED digit dac and the 2114 sounded better to my ears then the 5532.
You may also find an improvement by bypassing the safety resistors on the op amp supply pins. Never seen one actually fuse so it is quite safe to do. I am sure the resistors cause a slight voltage drop and some modulation.
These resistors, if removed also give beautiful access to the op amps for a dedicated separate audio supply....... A trick that would work on most Philips based players from the era up to about 1997 or so.
Oh yes, also stick an RCA pl;ug with a 75 ohm resistor across the digital output. It works wonders on virtually all players that have their digital out permanently enabled.....
Regards
Guillaume
I have not used other remotes with a CD75 but it is from the same era as some other philips units like cd471 and that remote works many players...
What JRC op amps does it use? The NJM2114 is a copy/equivalent of the 5532 and Marantz preferred it, using it as an SE upgrade on things like the CD50 that had 5532 as standard. I went through many dual op amps in a QED digit dac and the 2114 sounded better to my ears then the 5532.
You may also find an improvement by bypassing the safety resistors on the op amp supply pins. Never seen one actually fuse so it is quite safe to do. I am sure the resistors cause a slight voltage drop and some modulation.
These resistors, if removed also give beautiful access to the op amps for a dedicated separate audio supply....... A trick that would work on most Philips based players from the era up to about 1997 or so.
Oh yes, also stick an RCA pl;ug with a 75 ohm resistor across the digital output. It works wonders on virtually all players that have their digital out permanently enabled.....
Regards
Guillaume
hi tubenut.
the op-amps are JRC6045s, and it says above that 5532 🙂
I think i might socket them, and try some AD823s or OPA627s 🙂
the op-amps are JRC6045s, and it says above that 5532 🙂
I think i might socket them, and try some AD823s or OPA627s 🙂
Careful, 5532 is a dual op amp
I think the OP627 is single but play with OPA2134 and 2604....
It has always baffled me that 5532 is dual and 5534 is single, Philips logic?????
Your CD850 should be a canditate for single op amps. I really liked the OP176 I think it was when I had my CD850.
Guillaume
I think the OP627 is single but play with OPA2134 and 2604....
It has always baffled me that 5532 is dual and 5534 is single, Philips logic?????
Your CD850 should be a canditate for single op amps. I really liked the OP176 I think it was when I had my CD850.
Guillaume
Re: Maybe sensor is dead
I bought a nice plug, and a resistor, came in at £1.05, and it seems to, as you say - make things markedly improved...
Thanks a lot! 😀
Duncan.
...I'd not heard of this tweak before...tubenut said:
I bought a nice plug, and a resistor, came in at £1.05, and it seems to, as you say - make things markedly improved...
Thanks a lot! 😀
Duncan.
I've opened up the player once again, so as to disconnect the headphone section, and spotted that it has a CDM4/11...guido said:
Not really sure if that is a good thing or not... i'll leave that for you guys to tell me 🙂
That is good. CDM4 with hall-motor. Are the TDA58xx chips attached to the transport, or are they on the main pcb?
Just wondering, my CDM2 has them on a separate pcb underneith the transport. A CDM4/11 player i have, has them on the main pcb.
Just wondering, my CDM2 has them on a separate pcb underneith the transport. A CDM4/11 player i have, has them on the main pcb.
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