Author Topic: Replacement capacitors in CD94 mk 2  (Read 4893 times)

Offline brenden

  • Full Member
  • ***
  • Posts: 161
  • Liked: 52
Replacement capacitors in CD94 mk 2
« on: January 10, 2015, 09:37:41 PM »
Been a while since I posted ,with Christmas ,New  year and all .

I did get a chance to change the main filter caps in my CD94 mk2 ,that I suspected was causing the drawer to be extremely sluggish to close,to the point where it needed help  .The tracks were skipping from time to time ,and seemed sensitive to even small knocks .

    I replaced these with 8200uf 56v  Nippon Chemicon audio  capacitors .These were a larger version of the ones in the 94,which were  6800uf 27v   Chemicons . They are taller ,but fitted in perfectly.

     I can report the drawer problem is fixed ,and is now free from skipping and can give it a good knock without any problems .

      If any of you experience problems of this sort ,throw  in a pair of new caps .They arent expensive .    The new caps sound fabulous too ,and although I haven't compared to the Elnas ,I would guess they are easily competitive .
               
                   

Offline brenden

  • Full Member
  • ***
  • Posts: 161
  • Liked: 52
Re: Replacement capacitors in CD94 mk 2
« Reply #1 on: January 14, 2015, 03:16:16 AM »
Here is a pic of the caps I installed .

Offline brenden

  • Full Member
  • ***
  • Posts: 161
  • Liked: 52
Re: Replacement capacitors in CD94 mk 2
« Reply #2 on: January 14, 2015, 03:19:17 AM »
Also a .01uf  copper foil polystyrene I placed on the AC secondaries leading to the clock .
The idea was to reduce noise to the very sensitive clock ,and it worked a treat .
  the music was much  smoother ,and more transparent ,and also less hash that you don't notice until its gone .The copper foil on this cap  is obscured by the black butyl rubber  jacket which is there to reduce vibration .

Offline brenden

  • Full Member
  • ***
  • Posts: 161
  • Liked: 52
Re: Replacement capacitors in CD94 mk 2
« Reply #3 on: January 27, 2015, 12:33:18 PM »
New caps, leads  polished with silvo ,and loose fitting Teflon ,  prior to installation on the CD 94 secondaries . These are  beautiful  .01 polystyrene copper foil .

« Last Edit: January 27, 2015, 12:48:16 PM by brenden »

Offline stevenvalve

  • Administrator
  • Hero Member
  • *****
  • Posts: 1490
  • Liked: 259
Re: Replacement capacitors in CD94 mk 2
« Reply #4 on: January 27, 2015, 01:10:18 PM »
Brenden, nice job,,,, I have found that attention to detail is so important, I even use emery paper to clean and then use alcohol on the capacitor and resistor leads before soldering, as you know every little part and change impact's on the sound, In the future it wound be nice to run yours against a stock, and also a modified Marantz 94 mark 2 just to see where its at. 

Offline brenden

  • Full Member
  • ***
  • Posts: 161
  • Liked: 52
Re: Replacement capacitors in CD94 mk 2
« Reply #5 on: January 27, 2015, 02:16:03 PM »
The polishing is  great and its free ,especially if you leave the leads longer like I do with really rare and exotic parts like these caps

Wires and circuit traces are like road ways for the electrical signal especially the high frequencies that tend to travel more on the outer part of wire .Silvo or brasso will polish the wires to a lovely smooth finnish .The biggest benefit from polishing is a gain in  purity ,and  delicacy in the upper mids and highs.

 
 I tried my CD 94 II  against my stock one ,after I did the NOS mod but have made a number  changes since .The modded CD94 II won hands down. The stock one sounded dull and flat in comparison .I am working on the receiver board now ,and its just getting better  .I think you would get a shock if you heard what can be achieved with this one box unit .Its full of life .

Offline YoungSC

  • Jr. Member
  • **
  • Posts: 56
  • Liked: 0
Re: Replacement capacitors in CD94 mk 2
« Reply #6 on: April 22, 2015, 10:33:26 AM »
Hi Brenden,

I seem to be having a similar problem with my Drawer and disk hold down.  Where did you source your Nippon caps?  Do you have any more info on the cap model name?

Thanks,

Simon

Offline brenden

  • Full Member
  • ***
  • Posts: 161
  • Liked: 52
Re: Replacement capacitors in CD94 mk 2
« Reply #7 on: April 22, 2015, 04:01:23 PM »
Hi Simon, I think those came from  Yahoo  Japan  from memory .The Elnas for audio  are a great choice also .
  There is no guarantee that the caps will fix your problems as there are a number of things that can cause CD players to play up but caps are  a major suspect .I can check what I have left and pm you if U wish .I may have some spares .

Offline ozmillsy

  • Hero Member
  • *****
  • Posts: 2164
  • Liked: 245
Re: Replacement capacitors in CD94 mk 2
« Reply #8 on: April 22, 2015, 06:03:21 PM »
Here is a pic of the caps I installed .
Hey Brenden,   omodo also posted about this in another thread (that I cant seem to locate).    Can you post a larger pic of the cd94 , and highlight/circle the ones you replaced.   It'll help me pinpoint which caps I need to tackle.  My CD94 tray mechanism is cactus.
It's all about the music,, not the equipment.

Offline brenden

  • Full Member
  • ***
  • Posts: 161
  • Liked: 52
Re: Replacement capacitors in CD94 mk 2
« Reply #9 on: April 22, 2015, 09:08:11 PM »
Hi Oz , I cant get pics atm  but in a Marantz cd94 ,both MK1 and MK2  they are the 2 largest caps for the + and - supplies .You cant miss them ,they look like the twin towers  :)
   In the MK1 they used  Elna for Audio  6800uf  25v?, and in the MK2 they used  Nippon Chemicon 6800uf 27v  caps .

   It could also be possible that another  weak electrolytic  altogether can cause problems with circuitry ,and can only be found by testing or replacing one  by one .
 
    The ones I obtained ore almost identical to the ones used in the Marantz Project D1 ,Marantz's all out attempt  at implementing  the Dual TDA1541A double crowns .

      The slide bearings seem to give some trouble as well I think .I got some WD40 into mine but you need to cover the belts well  with rag before attempting that .It may  be even  better to dismantle the bearing ,but I didn't attempt it .Could be one of those disaster jobs .
 
         

Offline brenden

  • Full Member
  • ***
  • Posts: 161
  • Liked: 52
Re: Replacement capacitors in CD94 mk 2
« Reply #10 on: April 22, 2015, 10:00:39 PM »
Actually ,I think the MK1 had Elna for Hi Fi ,which was probably the same as the "For Audio" or  likely   just a  name change or minor improvements .

Offline Jehuty

  • Hero Member
  • *****
  • Posts: 1385
  • Liked: 110
Re: Replacement capacitors in CD94 mk 2
« Reply #11 on: April 23, 2015, 12:10:39 AM »
Hey Brenden,   omodo also posted about this in another thread (that I cant seem to locate).    Can you post a larger pic of the cd94 , and highlight/circle the ones you replaced.   It'll help me pinpoint which caps I need to tackle.  My CD94 tray mechanism is cactus.

Hi Oz, I used to have problems with the mechanism until Craig sold me a set of genuine CD94 belts. Then I asked Danny Digital to install them while he's working on my clock mods. No more tray problems afterwards.  ;)

See an old post from Craig below:
Looking forward to the comparison Oz, mine used the same digital RCA connections as yours but I can't do comparison because this is the only CD94 I have.

A little advice for all CD94 users, never let the CD94 unused for a prolonged period of time, I left mine for about 4 months unused when I was away and because of this the rubber belts started to slip due to developing shape memory, I can't load CD automatically anymore because the tray keep ejecting, so now in order to load the CD I have to push gently the big white roller close the transformer (see pic).

DD says all I can try to do is to re-lube all the friction points and try another belt, I haven't got time to do it but I really hope my CD94 can operate normally again after the treatments.

Cheers,
William


William,

I understand your experience with this.  I got a set of belts on Ebay from the USA which were supposed to a 'genuine quality' item.  I had many months of trying to sort out what I thought was a slightly sticky drawer mechanism etc.  I spoke with one of my Marantz wholesalers and they went 'Sure we have those belts'  so I got a set... and guess what... all the problems disappeared.  Works like a charm now with nice solid Marantz Tank-like action.  Amazing what the correct item will do.  Drop me a PM if you would like to try a set.

Cheers

Rawl
Not all that matters can be measured, not all that can be measured matters.

Offline brenden

  • Full Member
  • ***
  • Posts: 161
  • Liked: 52
Re: Replacement capacitors in CD94 mk 2
« Reply #12 on: April 23, 2015, 12:27:35 AM »
That is obviously the very first thing to check . I was assuming people  had checked the belts for slipping first .

    I use a couple of dabs of CRC belt grip (Supercheap Auto ) if the belts look to be in good condition but slipping a bit .I usually spray a little on a screwdriver head and dab on the underside of the belt .

   If the belts have began to perish or very weak ,new belts are required .

    If the motor seems to be  labouring after this ,other things need to be checked like the bearing guides and the bearing lubrication .

Offline ozmillsy

  • Hero Member
  • *****
  • Posts: 2164
  • Liked: 245
Re: Replacement capacitors in CD94 mk 2
« Reply #13 on: April 23, 2015, 12:22:00 PM »
Yep, belts have been done. 
It's all about the music,, not the equipment.

Offline rab

  • Administrator
  • Full Member
  • *****
  • Posts: 215
  • Liked: 30
Re: Replacement capacitors in CD94 mk 2
« Reply #14 on: April 23, 2015, 08:37:56 PM »
on the topic of belts, i finally decided to get my Wadia serviced by Danny, since it needed new belts the day i first received it!

I sent him an email yesterday, but it seems his email address has changed. If anybody knows his new address, can they please PM it to me?

Thanks!

- richard

Offline brenden

  • Full Member
  • ***
  • Posts: 161
  • Liked: 52
Re: Replacement capacitors in CD94 mk 2
« Reply #15 on: May 06, 2015, 10:22:31 PM »
Here is a photo for YoungSC. Showing placement of a cap I sent him .
    The digital signal passes through this cap .one thing I have learned over the years is that the digital signal is just as susceptible to quality of capacitors .For this spot we need a great high frequency cap .The  4700pf copper foil polystyrene is perfect for this .

Offline brenden

  • Full Member
  • ***
  • Posts: 161
  • Liked: 52
Re: Replacement capacitors in CD94 mk 2
« Reply #16 on: May 06, 2015, 10:25:56 PM »
This one shows the cap number .