advertisement


Marantz CD94 refurbishment

Mike P

Mike P

Trade: Pickwell Audio
There seems to be plenty of love for high end vintage CD players on PFM these days, so I thought I'd share with you some details of the refurbishment work I'm doing on a Marantz CD94 for @paolo191

@paolo191 wanted a unit in the champagne finish rather than the black finish we usually see in the UK. He actually ended up getting on from Switzerland, thanks to some kind help from @Dowser.

It's the first time I've seen a champagne finish CD94 in the flesh and it looks gorgeous!

20210504_145700 by Michael Pickwell, on Flickr

Both @Dowser and @paolo191 had already established that the unit was working fine, so I jumped straight into taking the side cheeks and cover off.

....and straight away encountered evidence of a previous repair.

20210504_150136 by Michael Pickwell, on Flickr

The screws that hold the righthand wooden side cheek on aren't original and had been changed for some longer and larger diameter stainless self tappers. For comparison I've included an original screw in this photo (the copper coloured one).

This is a common problem on these players and often the screws that hold the side cheeks on have stripped threads. It's caused by a combination of people doing the up too tight and also by people lifting the players by the side cheeks. Please support them from underneath when you lift them!

In this case someone had got around the issue of the stripped threads by fixing some J-nuts to the inside of the chassis, with what looks like JB weld epoxy.

20210504_150714 by Michael Pickwell, on Flickr

Not the neatest repair perhaps, and not how I like to do it but a perfectly solid and functional repair nonetheless.
 
An overview of the internals.

20210504_150601 by Michael Pickwell, on Flickr

All of the electrical components look to be original but straight away I could see some problems.

The first thing I noticed was that one of the power supply filter caps was badly bulging. This photo makes it look less bad than it is. In the flesh the top of this cap is very obviously domed and bulging.

20210504_161916 by Michael Pickwell, on Flickr

And joy of joys, there's loads of that nasty brown glue to remove too :mad: This stuff causes horrible corrosion to component legs and whilst it's really tedious work to remove it all it has to be done.:(

20210504_154519 by Michael Pickwell, on Flickr

Oh joy!

Several hours later it's looking much better.

20210505_214738 by Michael Pickwell, on Flickr

More knackered caps found along the way.

This 470uF 25v Elna Cerafine tested with a VLoss of 56%!
20210504_161853 by Michael Pickwell, on Flickr

Many of the wire jumpers were badly corroded and had to be replaced and also several of the resistors. Annoyingly one of them was a 1K47 which I didn't have and meant putting in an order with RS.
 
You are a dark magician, getting those caps out without removing the board to get at the underside???? How?

I'm surprised the DAC(?) is socketed too.
 
JimmyB said:
You are a dark magician, getting those caps out without removing the board to get at the underside???? How?

I'm surprised the DAC(?) is socketed too.
Click to expand...
No magician, the baseplate comes off.

I just fitted that socket.
 
Such a great deck. I had the black version.

Had a few capacitors replaced and the belts and it was as good as gold.

Quite difficult to find these in good condition with both the "Play" and "Stop" buttons intact.

The bevelled surfaces are fascias which are notorious for falling off.

Keep an eye out for the matching DAC!
 
Nice work as always Mike - I did mention it needed a recap and clean-up :)

Did you listen to it first Mike - I assume you're going to fit an A chip, and the later SAA I sent with it? Would be interested in your thoughts on differences. Going any further than that?
 
Oh, note that the drawer belt was replaced a year or so ago according to the previous owner. He owned it from new and it was the only problem he ever had with it.
 
Dowser said:
Oh, note that the drawer belt was replaced a year or so ago according to the previous owner. He owned it from new and it was the only problem he ever had with it.
Click to expand...

I think the seller was a bit erm.....'economical' with the truth. There's evidence of several other repairs, some good, some bad.
 
Dowser said:
Nice work as always Mike - I did mention it needed a recap and clean-up :)

Did you listen to it first Mike - I assume you're going to fit an A chip, and the later SAA I sent with it? Would be interested in your thoughts on differences. Going any further than that?
Click to expand...

I actually didn't listen to it first as I've already got a Philips CD960 which is the same player but with Philips badging. I've also had another CD960 which I fitted quite a lot of upgrades to, so I've already got a good idea what the CD94 is capable of.

Yes I'll be fitting the SAA7220P/B you supplied, together with a TDA1541A from my stash.

My recommendation to Paul was to largely concentrate on restoring it to 'as good as new' before considering any serious modifications. If after living with it for while he wants more done, I'll be happy to oblige.

Many of new parts I'm fitting are better than the originals so it will in truth be significantly better than new when done. And of course it'll be getting the SAA7220P/B and TDA1541A chip upgrades too.
 
Standard 5534's in there?

I remember you showing the big Sony's had lot's of individual regulation, how does the Marantz compare?
 
JimmyB said:
Standard 5534's in there?

I remember you showing the big Sony's had lot's of individual regulation, how does the Marantz compare?
Click to expand...

They're JRC5534D which is the low noise selected version. I know a lot of people would automatically pull these and fit something fancy. I've been there and done that (more times than I care to mention!) but I've come to the conclusion that in this implementation the stock op amps sound very good to me. Accuphase use them a lot too.

The CD94 has nice 'discrete' voltage regulation for analogue stage. The rest is handled by the three regs on the heatsink at the back of the player.

TBH I prefer the way Sony do things, with a separate dedicate reg sited locally right next to each major power consuming device.
 
Mike P said:
They're JRC5534D which is the low noise selected version. I know a lot of people would automatically pull these and fit something fancy. I've been there and done that (more times than I care to mention!) but I've come to the conclusion that in this implementation the stock op amps sound very good to me. Accuphase use them a lot too.
Click to expand...

Yeah, I'm not convinced that replacing 5532 and 5534's is ever really an improvement if the actual implementation is well designed.
 
Great work.
No manufacturer today could afford such a nice die-cast chassis.
Philips were really serious about their CD players.
Even the modest CD104 had such a base, albeit with a cheap plastic fascia!

JimmyB said:
Yeah, I'm not convinced that replacing 5532 and 5534's is ever really an improvement if the actual implementation is well designed.
Click to expand...
I've never be convinced either. Today I leave those well alone.
 
Mike P said:
Aickwell, on Flickr

And joy of joys, there's loads of that nasty brown glue to remove too :mad: This stuff causes horrible corrosion to component legs and whilst it's really tedious work to remove it all it has to be done.:(

20210504_154519 by Michael Pickwell, on Flickr
Click to expand...

It does more than that. It also starts to go conductive and shorts out PCB tracks, and then starts to eat away at them. That's exactly what the infernal stuff did inside my CD-94!

Dowser said:
Oh, note that the drawer belt was replaced a year or so ago according to the previous owner. He owned it from new and it was the only problem he ever had with it.
Click to expand...

Then they're probably due for replacement again. Mine chews though a set about every six months, or so it seems!
 
Very nice! So good to see love and care being put back in to these older pieces! Amazing how well they still can perform with a bit of TLC!
 
More updates:

This sorry looking thing is the push-rod which links the power button on the fascia to the switch, which is located near the back of the player.

What has happened here is that someone ham-fisted has tried to remove this 'in-situ' by bending it rather than either moving the front panel away of the switch assembly away. As a result, they've snapped the whole thing in two and also damaged the socket that the switch fits into.

20210507_082758 by Michael Pickwell, on Flickr

They've fixed one end with a small bent bit of metal and a big blob of araldite. And they've glued a length of threaded brass bar into the groove along the side of the bar as a splint. To be fair their repair seems to be holding up fine so I'll leave it alone.
 
More bodged fixes..

Another common issue I see with this laser mech is that the foam bump stops on the ends of the tray guide rod perish and crumble to dust. With the bump stops crumbled away the tray makes a load knock as it hits the end of its travel.

Here someone has replaced the foam washer with another one. They've split it so that it can be slipped onto the rod without removing it. The replacement washer has also now gone brittle and crumbly.

20210506_214828 by Michael Pickwell, on Flickr

And at the other end they've fitted this thin vinyl material washer (again split).
20210506_214806 by Michael Pickwell, on Flickr

I will be fitting a pair of steel coil springs as bump stops which will last indefinitely (see later photos).

The lovely brushless motor stripped down for cleaning and lubrication. The small PCB also gets checked over and any dry joints reflowed.
20210507_085916 by Michael Pickwell, on Flickr
 
You must log in or register to reply here.


advertisement


Back
Top