Marantz CD-84/CD-74 service manual?

[bleachershane]

Anyone have the service manual for these?

Just got my second CD-84 on eBay and it turned up today so itching to get to grips with what this machine is capable of. At stock, it's not a miles away from with my modded CD-63 SE! In fact, it's slightly more 'musical' sounding to my ears...! Goodness knows how, with JRC4560 op-amps in place, it's just not right lol

My first one was rescued from a bin worked for a few years and died beyond repair a few years ago before I got into hi-fi modding and had been searching for one since to see what these machines could been capable of given some attention.

Always been mightily impressed by the sheer weight and build of these players and the tank like CDM-1 transports!

So, if anyone out there has the service manual I'd be eternally grateful!

Anyone else think these machines, despite the 14-bit TDA-1540, sound damn good? Or is everyone ripping these out and replacing them for the TDA-1541/A?

[oshifis]

Hi,

My first CD-player was a CD-74 (bought second hand around '90), and I just recently replaced it with a CD-84... I modded it so much that even its developer wouldn't recognise it... I know it in and out, and I can give some ideas about modding it.

Here is the service diagram:

http://www.freeweb.hu/tube/Marantz.pdf
http://www.freeweb.hu/tube/Marantz1.pdf
.....
http://www.freeweb.hu/tube/Marantz7.pdf

[bleachershane]

First off oshifis, THANK YOU! Like I said, it is much appreciated!

Secondly, as someone that's had extensive experience with the CD-74/84 it would be great to hear about what you've done and achieved with your own units!

At the moment, my CD-84 is very much at ground zero, completely at stock and untouched. Sounds good but the only plans I've even started to get etched is
1) a good resoldering job (lots of dry and ringed joints)
2) complete recap (Panasonic FM/FC for power supply uprating original capacitance values, not thought about other caps yet)
3) Replace JRC4560s with LM4562s (same op-amps as in my CD-63SE)
Will possibly remove voltage selector and hard wire for UK 240V use as well.

Very basic stuff to start off with as you can see. So please go ahead with your suggestions, I am looking to hear what you have done!

[oshifis]

Here is what I have done (from memory):

- PSU diode bridges replacement to Schottkys
- PSU recap as large as fits in (1.5 to 2x original value)
- PSU 7805/7812s replaced to LM317 (some resistors added) <- biggest improvement
- output dual opamp replaced to a single version (OPA627), feedback 1.5k parallel 68pF. PCB cutting was necessary and a pair of DIP sockets were soldered in. Output filter stage removed.
- output capacitor replaced to WIMA MKS-4 4uF/63V (I know, I know...but it seemed a good idea then)
- NOS mod (http://www.freeweb.hu/tube/no_oversampling.pdf)
- TDA1540P STR1 signal reclocking with TTL 74S74
- Master clock replaced by a Motorola TCXO modded to 4.2336 MHz
- Rear PCB with variable resistors removed altogether with the black flat cable, but then I had to connect two pins at the other end of the flat cable, otherwise the motor did not spin up.
- I cut a rectangular opening in the middle of the power on button and inserted a red LED, connected to the error flag signal of the SAA7020 pin 36 through a transistor.

The problem with this unit is the tight internals.

[noyan]

Originally Posted by oshifis

Here is what I have done (from memory):

- PSU diode bridges replacement to Schottkys
- PSU recap as large as fits in (1.5 to 2x original value)
- PSU 7805/7812s replaced to LM317 (some resistors added) <- biggest improvement
- output dual opamp replaced to a single version (OPA627), feedback 1.5k parallel 68pF. PCB cutting was necessary and a pair of DIP sockets were soldered in. Output filter stage removed.
- output capacitor replaced to WIMA MKS-4 4uF/63V (I know, I know...but it seemed a good idea then)
- NOS mod (http://www.freeweb.hu/tube/no_oversampling.pdf)
- TDA1540P STR1 signal reclocking with TTL 74S74
- Master clock replaced by a Motorola TCXO modded to 4.2336 MHz
- Rear PCB with variable resistors removed altogether with the black flat cable, but then I had to connect two pins at the other end of the flat cable, otherwise the motor did not spin up.
- I cut a rectangular opening in the middle of the power on button and inserted a red LED, connected to the error flag signal of the SAA7020 pin 36 through a transistor.

The problem with this unit is the tight internals.

Hi,
I have a Philips CD104 and i want to install a clock like yours. May i learn, where did you buy Motorola TCXO 4.2336 MHz ?
Thank you,
Noyan

[ravenman]

Originally Posted by oshifis

Here is what I have done (from memory):

- PSU 7805/7812s replaced to LM317 (some resistors added) <- biggest improvement
- Output filter stage removed.

Hi, nice recommendation , please write me more details about added resistors (scheme) , iam bought new ST Microelectronics LM317T regulators to replace 7805/7812 and i dont know what cause a direct replacement without adding resistors

Question 2) , Whats components represent output filter stage ? (2x electrolitic cap in opamp output ?)

Thanks for the advice and sorry my english is bad.