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-   -   Marantz CD-50 and CD-60, TDA1541, CDM4/19 (https://www.diyaudio.com/forums/digital-source/201057-marantz-cd-50-cd-60-tda1541-cdm4-19-a.html)

UV101 30th November 2011 11:52 AM

If you are using better caps for bit decoupling, remove the originals 1st ;-) In my 960, I ran large 0.22uF MKP's and they were very good. The only thing I would consider is using a 1uF on the MSB (See the later sections in my clocking doc for details).

With respect to the smoothing caps, I think the biggest you can fit in for 2703,2713 and 2711 is 12.5mm diameter. You can get Panasonic FC 2200uF/25v (supply rails run at just under 25v) in that size for the +/-15v regs. That's what you can see from the top. I would then tag another same diameter cap in parallel with the one on top just because you can. More uF is better and parallel caps will have lower ESR. If you decided to use much larger TSUP's for all 4 and mount them remotely on the case, I wouldn't bother with the parallel caps under the board.

One thing I didn't mention previously is that the servo control for the transport is on the unregulated +/-10v rails in the diagram. The large smoothers will help the unregulated servo rails immensely and although I've never consciously measured it independently in this player, I have experienced significant gains in this area on other players. I guess what I'm saying is that the 22,000uF TSUP in my pictures is important!!! :-)

Edit - just checked my picture with the green caps under the board. They are a couple of caps attached in parallel to 2707. I must have used the largest cap I could physically fit in the top, the added a couple of 1000uF's underneath! Gives you an idea anyway.

tome 30th November 2011 12:24 PM

Hi
Maybe is not right place, but I like to ask something.
I have one 18 years old CD52 MKII SE, still working well but I like to do some modification and see what result I will get.
Basicly I know what to do, but I wish to find someone who already have expirience with this type of CD player and tell me if there is something special to do or some recomended modifications.
Best Regards
Tome

UV101 30th November 2011 12:42 PM

Quote:

Originally Posted by tome (https://www.diyaudio.com/forums/digital-source/201057-marantz-cd-50-cd-60-tda1541-cdm4-19-a-post2800602.html#post2800602)
Hi
Maybe is not right place, but I like to ask something.
I have one 18 years old CD52 MKII SE, still working well but I like to do some modification and see what result I will get.
Basicly I know what to do, but I wish to find someone who already have expirience with this type of CD player and tell me if there is something special to do or some recomended modifications.
Best Regards
Tome

PSU is and transport is identical so same mods apply in that area.

I think the CD52 MKII SE is identical to a philips CD850MKII which I had from new until about 4 years ago.

Principles are very similar. 1st the PSU, then the opamps in the output stage with their local decoupling caps. Identify the dac etc and replace the local decoupling caps. Replace the clock.

All the above will sharpen the sound bringing it forward. The separation and soundstage will improve and there will be increased resolution and detail. Beefing up the PSU will improve the dynamics.

There are lots of similarities between the 2 players. The CD50 is the older multibit DAC and the CD52 is one of the early bitstream dacs.

If you are interested, start a thread, I'll contribute and I'm sure many other will too. ;-) I've got a few pics I can share of my 850MKII with a Trichord clock and I think the pics I posted earlier with the Blutak around the transport may be from the 850MKII as well.

Edit, just checked and although its 52 is similar, the actual DAC chip is different - its the CD62 thats the same as the CD850MKII

Edit2 - just realise the Service manual for the 52 is on my website if you want it!
http://www.hifisounds.co.uk/manuals/CD32_42_52_doc.pdf

As is the CD50

Mayday 30th November 2011 01:08 PM

Can I use 680uF/25V ZLH for (2654,2634,2653on TDA, 2632 on SAA7220 and 2607 on SAA7310)?
For ((2704,2714,2708 & 2712) I can get 68uF/25V or 680uF/25V(not sure the bigger ones will fit) original is 47uF/25V.

UV101 30th November 2011 01:32 PM

I'd possibly not go as high as 680uF for local decoupling close to the chips. There is an argument that if you go too high in uF too close, you slug the supply down I tend to use a maximum of 470uF and often even 220uF. The highest voltage you'll see is 15v on (-15v on DAC). The rest are all 5v or -5v rails so you can use lower voltage caps which would be smaller in size. The opamp decoupling will also only see a maximum of 15v. Given that you often buy in multiple of 5, I'd work out what I can fit and where. I'm pretty sure that if you go for 470uF/16v, they'll fit everywhere post reg ;-) I think they are 8mm diameter.

Mayday 30th November 2011 03:19 PM

What I've got at home...if any of it can be used.

Pana FC: 100uF/50V 15pcs, 1000uF/50V 3pcs.
Rubycon YXF: 2200uF/50V just one.
Elna RJH: 2200uF/35V 2pcs
Nichicon MUSE: 2200u/50V 4pcs
Nichicon VZ(M): 2200uF/35V a few.

A large number of caps, unused, that I don't know the quality of:
United: 470uF/25V 10pcs
Huang: 3300uF/25V 10pcs
VENT(?): 1000uF/16V 8pcs
Jakec: 1000uF/25V

Got plenty of filmcaps in various values.

What to buy:
What about Sanyo OS-CONS? 270uF/16V, 470uF/16V.
Did find TSUP, but they were rather expensive. Any more common alternative?

As for opamps, I've got OPA2134 at home, atleast 4pcs, what do you think about them?
Many recomend LM4562?

Mayday 30th November 2011 03:50 PM

Regulators:
I'm thinking maybe soldering my own using LM317 and LM337 might be the most costeffective way to go?
Will have to make the boards/board small though since there are 4 regulators according to the schematic.

tome 30th November 2011 04:00 PM

Thanks a lot UV101 for manual and advice, I already follow this thread and I'll wait to see Myday progres and results
Thanks
tome

josha 30th November 2011 08:20 PM

Great advice from UV101, I only went NOS because I broke my 7220(!). Until then the biggest gain was a dedicated PSU for that chip - I built a simple 317 based regulator, just a couple of caps and resistors, make sure you bypass the resistor on the ADJ pin, this improves the ripple rejection a lot (look at the 'Adjustable Regulator with Improved Ripple Rejection' suggested circuit on the LM317 datasheet).

You might also find this interesting.

If it helps, my PSU (so far) is as follows;

Original transformer and PSU for the control, pickup and TDA1541
+1 Transformer to the clock
+1 Transformer to +/-15v LM317/337 PSU for the opamps
+1 Transformer to +9v LM317 regulator feeding 2 x LM317 regulators for the 7220 & 7210

The TDA1541 will benefit from it's own PSU but you make it a lot cleaner by isolating it from the 7220 and output stage and I don't fully understand the requirements of the 1541 PSU yet.

The clock upgrade recommended by Andrew is fantastic, big improvements again (it's this one) very easy to implement as it has the required clock plus /2 and /4, on-board PSU and it's a bargain!

The PSU's will bring big gains on their own though and they're easy to build on stripboard, just experiment! You can get packs LM317/337 cheaply and you don't need to worry too much about the quality of the components (yet!), building a basic 5v psu will give you confidence and bring big gains in sound quality. Check your work carefully and test the PSU before wiring it in!

Have fun!

Mayday 30th November 2011 08:59 PM

Thanks guys!
I've build regulated PSU's before but that was years ago.
I'm taking in all your advice :)


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