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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)

Stabby 3rd March 2015 12:28 AM

Can I use a regular wall adapter (12V DC) to feed an LM317 for the SAA7220? I won't have the necessary parts to build my own PSU for a couple weeks but I wouldn't mind a preview of what to expect!

Stabby 3rd March 2015 02:51 PM

I removed the LM317 at the DAC. I made the mistake of not taking into account the LM317's 1.25V voltage drop. I measured and the TDA1543 was running at only 3.75V!

I put the LM317 at the SAA7220, feeding the input from the PSU prereg. This is a huge improvement! Much more clarity and everything sounds more lifelike. I'm extremely happy with this mod!

Next up: opamps! I will try both LME49720 and LME49860. I think I might order a Flea kit as well to do a clock upgrade.

Stabby 3rd March 2015 06:59 PM

Opamps replaced. I found the LME49720 too bright and not very comfortable to listen to. That could be because of CD610's bad power supply to the opamps though since it sounds brilliant in my slightly modded Marantz CD63. Then again I did way more mods to increase clarity in the CD610, maybe the LME49720 was a bit too much on top of all that.

Current opamps installed are NE5532. They sound more mellow and comfortable to me. Any suggestions for other mellow opamps?

Also I officially hate lytic DC blocking caps now. I removed the Silmics and it sounds much smoother without them. Maybe the Silmics just haven't had enough break-in but it's much better without them.

Stabby 3rd March 2015 07:33 PM

I'm having my first problem. Suddenly the player decides to automatically fastforward and when I turn the player on and off I hear a pop so there's something wrong with mute. Any idea?

Stabby 3rd March 2015 08:18 PM

Muting is restored by putting the (polarised!) DC blocking caps back. Apparently there needs be a polarised component in place of the DC blocking cap if I want to remove it. Any suggestions?

Also at times the player still starts to fastforward by itself. Turning off and on fixes it, sometimes for an hour, other times for only 5 minutes. Where should I look for the cause of this problem?

Stabby 3rd March 2015 09:05 PM

I tried replacing the DC blocking cap with a resistor which didn't work. Then tried a 4.7uF non-polar Panasonic polypropylene cap and muting is back to normal. So it looks like some capacitance is required for muting to function, polar or non-polar.

Not sure if I like the sound of the Pana film caps...

Stabby 4th March 2015 12:09 AM

It's getting lonely here! :p

Anyway, I change my mind about the Pana film caps. Combined with the LME49720 they sound SUPERB in the low to low-mid frequencies. Higher mids are smooth, I could listen for hours at high volume. Treble is definitely missing though (no DC caps made for great treble). Also tried LME49860 + Pana caps but bass and lows were way too heavy.

Defined low mids are what I've always been looking for. I'll put some inductors/ferrites and Oscons at all the digital chips where I haven't put any yet and see what it does for clarity.

Stabby 7th June 2015 02:42 PM

Getting back to work. My Philips CD610 wasn't a very successful experiment. Made a lot of changes but it didn't sound much better than an unmodded CD620, even after putting in seperate LM317 based regulators for both TDA1541 and SAA7220. Then again, the CD610 has a TDA1543 while CD620 has a TDA1541A, and the CD610 had NO regulation for +/-15V Opamp rails, so I they weren't really comparable to begin with.

Problem is regulators mostly. I've done a lot of searching around but I remain clueless on anything more complicated than an LM317. Can't find any suitable and simple shunt reg schematics, and something like an Spower reg or Salas would cost at least €50 for bare PCB + good parts.

Advice regarding regulators is very welcome but I'm not really expecting to find a cheap solution anymore...

I'm setting up my next order and these are the plans I have for another player (CD620 most likely):

- UCC PSA polymer caps (220uF) for DAC digital rails (supposedly the best affordable alternative for Oscons), Nichicon R7 100uF polymers for other digital rails.
- Toroidal transformer + TPR for SAA7220
- Regulator for TDA1541? Can't find anything simple/affordable so will likely just use LM7805... but I'm dying to find a better alternative
- Nichicon KZ lytics for analog rails
- Coupling caps: replace 100uF bipolar with 2x 100uF Silmic II back to back
- DEM mod
- Same mods I did with CD610: replace diodes, opamps, prereg caps as large as possible
- Maybe: Flea clock

Other than that I don't know what more I could do without spending a lot of time and money.

starkeyg 8th October 2015 05:51 PM

Regarding the Silamc caps - Cycil Bates research on caps showed that replacing a polar electrolytic cap with a bipolar one can cut the distortion by 1/4 or so. If you increase the capacitance size (uf) / or the voltage rating, you can cut it even further.

I replaced 220uf/16v/polar silmac caps in the output of my marantz sa/cd player and noticed what sounded to me as a more balanced sound. IMHO. Used 220uf/25v/bipolar panasonic SU caps. Pretty happy with the results. FWIW.

Regards,
Greg

dogwan 16th December 2015 09:26 PM

A big thank you to all the originators and contributors to this thread!

I recently picked up a Philips CD-60 from a local electronics recycler for $23 and it appears near mint.

After re-greasing the bearing (no divots!) in the stabilizer puck and adding mass it tracks like a champ! This is THE FASTEST initializing cd player I've ever seen.

All evidence leads me to believe this unit has very low hours. No signs of distress on the drawer gear. No lettering wear marks on or around any of the buttons.

Have already removed variable output and headphone section and replaced output coupling caps with 10uf films and it is sounding really good. Still a little grainy on the top end.

Ordered all the parts yesterday to start modding it. Have a copy of the Marantz CD-50 manual and appears identical. Some details are pretty cool like copper screws throughout, nice aluminum feet, polished copper backplate (see pic). But then the thin undamped cover and galvanized bottom plate have me scratching my head.

Here's what I plan on doing....
-Full recap of PS (based on rec's of UV101)
-Upgrade opamps to LME49720HA (also my favorite)
-Replace Diodes with Schottky's
-Install an IEC inlet for better power cord (also provide tap point to wire in....
-2x transformers for independent (local) regulated PS to 5v rails for 7220 and 7310 chips
-upgrade all local decoupling for chips and opamps
-DEM lock cap
-Copper line and damp with Dynamat chassis.

That's probably as far as I will take it, but may consider re-clocking if I can figure that out. Pretty sure this is going to replace my Rega Planet2000.

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