Saturday, 16 August 2014

Marantz CD84

Philips acquired Marantz in 1980 to try to broaden their appeal to the high end audio market.  This opened an interesting period that covered most of the CD player era, where both Marantz and Philips were designing separate but similar lines of players and releasing them under their own or the others name.  This led to pairs like the Philips CD473 and Marantz CD65DX, externally very different, but internally the same (and both made by Philips) and the Marantz CD72 and Marantz CD60, externally almost identical, but internally completely different (the CD72 being a Marantz, and the CD60 actually a Philips).

Aside from this, there were a few models that were fairly unique to their own brand, and the Marantz CD84 (and the similar CD74) was one of these.  It doesn't have a close Philips equivalent, and apart from the core chipset, it's almost entirely Japanese.

Externally, it has a number of unusual features; on the back, above the analog outputs, there are a pair of potentiometers that allow you to set the level of each channel separately, as well as an 'easy bus' connector (no, I don't know what it does either, probably something to do with recording CDs).

Inside, the player is laid out with the main transformer and loader on the left, and most of the electronics on the right.  The decoder and servo boards sit in a metal frame with the component side facing each other.  The loader is a standard Philips type that can be found in the CD104 and other players.

The servo is fairly similar to that found in other players using the CDM1, but uses a mix of Hitachi, Sharp and JRC parts.

The decoder board is again fairly similar to other players using the fist generation Philips chipset, but executed with Japanese, rather than European, parts.  In particular, note the epoxy dipped reed relays, film and copper foil capacitors, Anritsu relay and JRC opamps.  Being a very early player, the TDA1540s are a ceramic DIP package type.

Behind this frame is the player's power supply.  The huge heatsink is a reminder of how inefficient the first generation chipset in the player was.  These ICs consumed 500 to 1000mW each, and there's a few of them.

That lump on the back of the player isn't a transformer, it's a mains filter.

Here's the most interesting thing about this player though; a completely separate Japanese version of the CDM1.  In the CD84's service manual it's referred to as a CDP-3.

The most striking feature from the top is the turned brass spindle.  This version also has a cast aluminium alloy chassis, but there isn't the webs like the Philips made one.

On the bottom side there's a different preamplifier and motor driver board and a different spindle motor.  This CDM1 uses a brushed motor, but it's Japanese made, and different from brushed motor used in the CDM0.  The actual swingarm seems to be the same, apart from the oversized brass nut, I'm not sure what the purpose of that embellishment is.

Apart from the CD74 and CD84, I'm not sure where else these were used.  The Marantz CD94 seems like it would, but as far as I'm aware it doesn't, it just uses a regular Philips CDM-1.  If anyone knows of others, please let me know.

I'm not intending on modifying this player at all, as there are other much more suitable players for that.  The last notable thing about this player is that unlike most other players this old, it actually works.  No modifications, no replacement parts.  Very impressive.


  1. Hi Anton, I just finished assembling your LJC. Nice PCB! Triggered by your blog, if you would have to choose which Marantz player you would hunt for to get highest quality sound at reasonable price (after upgrading etc) which one would you go for? I thought of the Marantz CD-80 but I'm pretty sure you have seen far more players and can give advice.
    Thx in advance.

    1. Hi Rasco,

      Glad the LJC assembly went well. The CD80 is a good choice, I'm not sure I can think of anything better. An alternative would be the CD92 family, but they're not as easy to work on. If you like the TDA1547 (which I do), the CD15 and CD16 could be options.


  2. Hi Anton,
    I got my hands on a Marantz CD84. I purchased new caps for the PSU and Audio PCB. I wonder if the Japanese CDM1 is as reliable as the Philips made one. Opamps I will be using LM4562, the 3rd opamp, i will leave as it is the headphone. My CD84, has an issue with the draw, so will grease it and check the caps. As for Schottky diodes, i got 3A 40V? they look rather large? maybe another sort of Schottky diode I should use?
    Thanks. Regards

    1. I wouldn't expect any difference reliability between the two. The laser, photodiode array and optics are the same, and the chassis won't have an impact. The motor and spindle might, but I can't say which would be more durable. What I can say is that they're both very reliable.

      Be aware that your opamp replacement is far faster than the original, make sure it's stable.

      Replacement diodes is going to be a bit awkward for this player, as it uses a single inline diode bridges, not individual diodes.

  3. Hi Anton,
    What grease do you use on the CDM1 tray? Thanks in Advance

    1. I've not had to actual do this much. If I was to grease the tray, I'd probably use something like this: