Micro-Seiki CDM-2 - partial dissection [Archive]

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DSJR

13-06-2010, 19:39

I've been living with an occasional "cracking" sound from my CD player and I finally lost it when the drawer decided to go slow and squeal.

Removing the thing from the cupboard is a royal pita, as this machine is so darned HEAVY - far more than I remember the CD94 donor machine being.

First, a pic of the Sicomin platform-

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1363.jpg

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1364.jpg

For some reason, adding this thing made the same difference as adding the Trichord Clock 2 (more of this later) - I had two of these machines to compare..

Here's the machine "on the bench" - well, a rickety Dunhelm Mill TV table ;)

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1366.jpg

First to remove the solid rosewood end cheeks-

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1367.jpg

Then the heavy milled top which was re-sprayed by Target Audio-

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1368.jpg

This is the inside - copper city..

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1369.jpg

The DAC board is mounted on the side and the Trichord clock is neatly fitted next to it. I removed the rear copper "lid" and this shows the added balanced output board Micro Seiki added, together with the HiFi grade Elna caps..

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1371.jpg

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1372.jpg

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1374.jpg

I think the basic supply board is Marantz, but there's much changed I think. I have a couple more shots of the mech and elaborate "drive-cord" drawer mech and I'll post them tomorrow. For now, the bigger drawer belt is too badly stretched and will have to be replaced.

Something else, there seems like a waxy substance around all the supply caps. I don't think it's leaking caps, as even a couple of small ones have this. I still think the two Elna "HiFi" grade ones may need replacement, but I'm too much of a coward to try to delve any deeper. perhaps the thick MDF/Rosewood bottom could be removed to gain access, I don't know at present. The engineer I'd trust with my life and who had another of these packed it in several years ago and is probably retired now :(

If it does go to anyone for service, it'll have to be taken as I wouldn't trust a carrier......

Just thought you chaps would like to see another good player from the "Golden Age.."

John

13-06-2010, 19:44

Looks a nice bit of kit Dave

Rare Bird

13-06-2010, 19:56

Nice Dave

Spectral Morn

13-06-2010, 20:03

Hi Dave

Looks very nice.

If its like a Marantz CD94 then the entire unit is built into a die cast metal box. Looking at the photos again it is not built into a die cast metal box they must have just used the fascia and used a new construction for the sides and back.

I would offer to open my Marantz up for you to see photos of it but it is going to be very hard to get hold of it, as I would have to move a bookcase of CDs(+bookcase), a pile of tuners and a BAT VK75 power amplifier to get to it.

The CD mechanism is the same as my Marantz but the rest of it is different, no copper shielding in mine as far as I can remember.

Hope you sort it out as it would be a shame to let it go to pasture.

Mark of Audiocom could help I would imagine or maybe even Stan Beresford ?

Regards D S D L

Rare Bird

13-06-2010, 20:06

Hi Dave

Looks very nice.

If its like a Marantz CD94 then the entire unit is built into a die cast metal box.

The old Mission 7000 Philips jobby was a diecast frame aswell

aquapiranha

13-06-2010, 20:13

They don't build 'em like they used to. Nearly dropped a CD85 once, could have been very bad for my toes that..

Spectral Morn

13-06-2010, 20:19

The old Mission 7000 Philips jobby was a diecast frame aswell

The first time I took my Marantz CD94mk2 apart was a real shock as every part of the player is built inside this 5mm deep diecast metal box the rear and sides are bolted on to it as is the fascia.

The one area of weakness was the 1mm thick metal base, so I replaced that with a quarter inch brushed aluminium one and wow what a difference that made to the sound. Micro Seiki looked at the bottom of it as well, hence the heavy addition to their version of the player. I also recall a British firm (not Woodside) who had rebuilt the 94 into and even bigger tank of a player by adding to the bottom sides and rear of the player.

When Marantz brought out metal end cheeks I tried at the time to buy some but Marantz had no spares that they could sell to me. I like the wood sides but felt that metal ones might be better, I never got to find out.

Anyone got a dead CD12 or 95?, as the metal end cheeks would fit a 94; hole mountings are in the same place.

Regards D S D L

Spectral Morn

13-06-2010, 20:22

They don't build 'em like they used to. Nearly dropped a CD85 once, could have been very bad for my toes that..

Nice player that uses the same laser as the 94s Philips CDM1 mineral loaded :) Generally regarded as the best transport ever made.

Regards D S D L

aquapiranha

13-06-2010, 20:23

Nice player that uses the same laser as the 94s Philips CDM1 mineral loaded :) Generally regarded as the best transport ever made.

Regards D S D L

It belonged to shop I was working in at the time. I am sure they would not ahve been happy! :)

Spectral Morn

13-06-2010, 20:25

It belonged to shop I was working in at the time. I am sure they would not ahve been happy! :)

It would probably have survived the drop functionally if not cosmetically but your toes would have been a right off :(

Regards D S D L

Rare Bird

13-06-2010, 21:36

The one area of weakness was the 1mm thick metal base

Exactly the same on that 7000 wasnt even a mill thick..However they were built like tanks back then..

DSJR

14-06-2010, 08:43

I've just noticed that the bottom of the CD-M2 is a heavy metal plate similar in thickness to the top one.. Why I thought it was MDF I don't know, but the CD-M100 did seem to have something like this - I don't move the thing as a rule and it's the first time in ten years since I've taken the top off...

Here are the troublesome loading belts - how complex does this need to be?..

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1375.jpg

...and the wonderful CDM 1 pro(?) mech. Someone has GOT to make replacement light-pens for it at some point?

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1376.jpg

I found a replacement belt from Cricklewood Electronics (there was another site who wanted double the price) and should hopefully receive it tomorrow :) The other belts were still tight with no slippage or stretching.

Spectral Morn

14-06-2010, 09:34

Looking good Dave, looking good :)

Regards D S D L

DSJR

14-06-2010, 16:21

Neil, sorry to have not got back to you, but *when you have the time and inclination...* is there any chance you could fish the CD94 out, whip off the top and take a piccie or three? I haven't attempted to remove the bottom plate, but I suspect that there's a Marantz chassis that Micro-Seiki have adapted in there..

How I wish I'd have bought the mint CD-M100 I was offered for £500 from a trusted friend. I know it had more bass power and punch than mine, but at the time it ruined my system (not the CD player's fault at all I discovered). The output transformers are bigger, the case even heavier (it was a bit taller) and there was a facility for turning the display off, which did make a very tiny improvement, as well as allowing you to quietly keep the machine powered all the time (those old 1541 chipsets needed it IMO).

One final memory. The phono sockets come straight off the traditional "analogue output board" under the add-on one. Used with decent standard phono leads, the sound reverts to CD94-type, rather closed in, dead and a bit "fuzzy." Adding cable ferrites to the interconnects closes the gap between them and the transformer coupled outs, so I suspect the transformers were self saturating RF and other cr@p coming off the DAC's.

Spectral Morn

14-06-2010, 16:34

DSJR

14-06-2010, 17:55

There's one already there mate...... :) I had thought of shorting out the the phono outputs too and had some Jimmy Hughes Specials, complete with reef-knotted wire links (don't ask), but they seem to have disappeared like a lot of stuff..

DSJR

18-06-2010, 14:56

Well, the crackle got worse and didn't abate after an hour or so, so I got my carcass into gear again and thought I'd remove the base of the player.. The rosewood trim runs round three sides and holds the badge, which is also the main switch.

I used to joke that the case of this machine was lead lined - IT IS - underrneath anyway-

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1378.jpg

It seems that some parts of the supply board do indeed run warm, and there are also some mods done to it By Micro-Seiki, including a couple of wires, which I don't think were part of the Philips donor chassis (apparently, Marantz, Philips and Micro-Seiki used part of a basic Philips two-box chassis and worked on these to individualise the players such as the CD94, Philips CD960 etc and the CD12/CDA94 used the DAC chassis apparently).

http://i132.photobucket.com/albums/q8/DSJR_photos/Microunder.jpg

I touched one of the black wire ends and the tarry substance/glue crumbled in my fingers. I have no idea if there were any components on this side of the wire (there's a diode and resistor at t'other) but it looks as if the wire was "split" in a Y form and terminated in two places. As the solder pads would have needed filing or a session with a Dremel to clean up, I found a clean pad and soldered a repair to that-

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1384.jpg

http://i132.photobucket.com/albums/q8/DSJR_photos/MicrounderFaulty.jpg

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1387.jpg

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1386.jpg

I've yet to plug back in, but here's hoping......

The CD94 and CD960 have service manuals, but I don't know regarding the CD-M2.

TTFN..

Rare Bird

18-06-2010, 15:12

See what I can do Dave.

If you put a shorting plug into the digital out you also get an improvement in sound quality. If you need one I have a few spare.

Hi Neil
Is it just a 75 Ohm Resistor wired in the plug your using?

Spectral Morn

18-06-2010, 18:23

Hi Neil
Is it just a 75 Ohm Resistor wired in the plug your using?

I will have a look later for you.

Regards D S D L

DSJR

18-06-2010, 19:15

I FAILED!!!!! :(

With this wire disconnected, the machine seems to function. Wired as I did it (trying to copy what I thought it was), the discs wouldn't turn. Disconnecting this completely, the disc spins properly. Neither the CD94 or earlier Philips 960 has this.

Ideas anyone please.

Rare Bird

18-06-2010, 19:24

I'm lost here dave whats happened?

Ali Tait

18-06-2010, 19:27

Looks like there was a resistor originally?

Rare Bird

18-06-2010, 19:31

Ah right so this is a Micro Seiki addition to the CD94 board!

DSJR

18-06-2010, 20:14

Yes. This basic DAC/Supply board is generic to several machines, the CD94 being the most well known. Micro Seiki fitted fancy caps, cit an earth path on the board and re-routed it, separating further the power supply ground from the DAC-signal ground. This one is another Micro Seiki mod, and because of this, it seems to be uncatalogued. When I touched the cable, it basically came away, leaving a wire "tail" on the leg of the transistor it seemed to connect to. The tarry mess just crumbled, leaving no record of what was there.

I'm baffled...

DSJR

19-06-2010, 13:00

I found the heart of the crumbled chunk and on carefully scratching the gunk away, it looks to be a PNP transistor - an A1175 (2SA1175?). I've located some on ebay's "Little Diode" and will order a couple. Hopefully, I'll be able to get the thing round the right way..... :scratch:

Tweedle-Dee

20-06-2010, 16:05

Many thanks for posting these pictures of your beautful CD-M2 - I always wondered about how much was from the CD94. I have a CD94II sitting on my coffee table at present. I could organise a few photos, if there are any common elements that you're interested between it and the mkI. Also check out this expired ebay posting here that has a few nice inside shots

http://cgi.ebay.co.uk/MARANTZ-CD94-MK1-SPARES-REPAIR-/330415951343

Hope this helps

TD

DSJR

20-06-2010, 17:17

Many thanks for the link. That bloody gunk is round the supply caps of the 94 as well!!!!!

The two large supply caps on mine are 6800uF Elna HiFi ones, but I can't seem to find a modern Elna equivalent as and when I choose to replace them. No bulges so I hope they're still ok.

Sadly, noone takes the bottom off to show the underside of the boards which is where my problem lies. I've downloaded a scan of the CD94 service manual, but it wasn't a good one, sadly.

I'd appreciate a few pics of the CD94Mk2 for comparison, although mine has the single TDA 1541 chip. I know the CD-M100 lacked the copper screening cans, but had copper strips glued to the tops of some of the IC's (can't remember if it had the twin DAC chips).

Ali Tait

20-06-2010, 17:26

Any good low ESR cap will do to replace them Dave.Given the age of the player,I'd replace them anyway,for peace of mind if nothing else.

Rare Bird

20-06-2010, 17:44

Many thanks for the link. That bloody gunk is round the supply caps of the 94 as well!!!!!

6800uF Elna HiFi ones, but I can't seem to find a modern Elna equivalent

Nichicon KG :)

DSJR

20-06-2010, 18:31

Thanks Ali & Andr'e

Rare Bird

20-06-2010, 18:43

Snap In. Measure your old pin centres

http://www.hificollective.co.uk/components/nichicon_kg.html

http://www.hificollective.co.uk/pdf/nichicon_kg.pdf

DSJR

20-06-2010, 20:37

10mm...

I wonder if 10,000uF 35V would be ok instead of the 6,800uF 25V in there already? Total overkill for a CD player, but not too expensive and they'd be the same size, give or take - the existing ones are 30mm diameter.

I've been enjoying LP's in the meantime, but need the CD player back.

Ali Tait

20-06-2010, 22:11

Would be ok and would work,but may change the tonal balance IMO.Perhaps for the better though,try it and see.More capacitance is not always better,but YMMV.

DSJR

22-06-2010, 12:05

Ali & Andr'e, Vishay do some 6800uF 25V ones the right size and low ESR. Would these be worth considering?

Right - replacement transistor arrived today, so I took a deep breath and fitted it the way I think it should be judging by the bent centre pin of the one removed...

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1392.jpg

Prior to closing, I removed the second copper can from the top and took a pic for posterity -

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1390.jpg

Here are the feet used for this model (the CD-M100 used pneumatic feet I understand)

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1400.jpg

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1399.jpg

Finally, small images of the knackered and corroded transistor-

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1398.jpg http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1394.jpg

Apologies for all the pics, but hopefully this sorry tale will help the lucky few other owners of Micro Seiki CD players.

Finally, I still have a faint rustling on the audio output. I'm hoping that this is supply caps getting tired :scratch:

DSJR

27-06-2010, 10:22

Final piccie instalment. The cracking noise is still there on the balanced output, so I tried the phono outs, labelled as "Output 2" on the back panel. Very faint rustling but no cracking.

I took the top off and started again, dismounting the added balnced output board..

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1401.jpg

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1402.jpg

Note the larger than average CD94 green caps around the DAC chip [TDA1541A] and loads of Elna cerafine caps (I believe the Philips and Marantz models used them too). The designers of this donor chassis did try hard at the time IMO but by today's standards it all seems so complex.

To close, it's been said that modern cheaper machines pee all over a CD94 and it wouldn't surprise me, but it would be a shame to ditch such a solidly built machine IMO.

P.S. I still haven't totally cleared the noise, so it's got to be either a noisy transistor in the power supply (it's on both channels) or a faulty cap which I have no way of locating. When I can, I'll buy an Alpha 5 CD player or similar and do it up for fun.