All electrolytic caps will be swapped to Pana FC or OS-CON.
Waiting for DIP8 sockets to arrive as I want to be able to change opamps and see which I like better.
Separate regulators or a really good one like this:
I will do the NOS mod too.
I guess caps are SMD on the bottom of the PCB on the CD-60(which is the one I started working on, so 220nF decouplingcaps will have to be soldered like this (pic borrowed from lampizator)?:
Looking at different clocks atm, but there are many...especially when you look on ebay aswell as on the known one like kwak, tent, LC etc....just dont know enough about it to make an informed choice(cost/quality).
EDIT: It seems the new flat surface of the clamp(correct word?) fixed the issue w skipping and too fast spinning on the CD-60 :)
Been reading on lampizator about the NOS mod, but I don't understand the "SAA7310 18th leg for MUTE wiring of NOS mode".
Sorry if I'm assaulting with posts :(
CD-50 PSU(same as CD-60?), what to swap, and to what value(brand, modell etc)?
So the NOS mod would be:
1. Desolder the SAA7220B/P, remove it
2. Solder a 24-pin socket to its place (with round holes)
3. Bridge the following pins on the socket with rigid wire: 1-18, 2-16, 3-15
4. Connect pin 23 of SAA7220B/P socket to pin 11 of SAA7210. This is where the MUTE signal goes from the uP.
5. Remove the crystal
6. Connect your 11.2896 MHz external clock to pin 19 of the SAA7210
This is what I have done and it works fine.
external clock will be a later mod.
SAA7210? I'm using the servicemanual for the CD-50 until I get my hands on one for the CD-60 too. I can''t find a SAA7210 in the CD-50 servicemanual atleast, just SAA7310.
Is this a NOS mod that doesn't require cutting traces on the PCB?
Sorry for my ignorance, new to cd-player mods...but I have done a fair bit of diy.
Hi Mayday, good luck with this! I'm having a lot of fun with my similar player, mostly thanks to the people here!
The NOS mod for the CD50/60 is described in some detail here, you can alo see that SAA7310 in place and how to hook it up.
Hope this helps, josh.
Thanks Josh :)
Hi Mayday, I've got significant experience with this chipset and indeed this player. My advice is NOT to go NOS. The main reason that most people do it is because the SAA7220 is a greedy chip that introduces noise onto the PSU rails. It is also responsible for clock distribution as well as performing the oversampling function. If you are looking for cheap short term gains, you can try NOS but the single best mod to perform in this player is a separate good regulator to supply the SAA7220 chip. This will give you benifits that the oversampling chip brings without the side effects! There are differing opinions, most only speak with experience of one or the other. My philips CD960 (Marantz CD94 MKI) didnt stay NOS long. As soon as I connected a premium regulator to the 7220, there was no turning back. I do sometimes put CD50's into NOS and sell them on eBay with a new basic mods because as said, its better than standard and costs nothing to do. In my player, I ended up with over 20 dedicated low noise regs, from many seperate PSU's, tried various clocking options and output stages. You really can get lots from these players if want.
One quick win! If you are not going to use the variable audio out (the board on its own on the right) unplug it!!!! This will remove it from the +/- 15v rails. These are the rails that run the opamps in the output stage and the -15v is also for the TDA.
There are 3 area's to look at to start (other than the seperate reg for the 7220). The PSU (next to the transformer at the back). The output stage (opamps and caps to the right of the main board behind the TDA chip) & the decoder (SAA7310), filter (SAA7220) and DAC (TDA1541).
In the PSU, space is very tight. I would replace the caps after the regs (2704,2714,2708 & 2712) with 470uF Rubycon ZLH (I personally do not like Panasonic FC after the regs or for local decoupleing). The ZLH will be larger but you can make them fit. The Caps before the regs are a little more tricky!! The general rule of thumb with these "Smoothing" caps is bigger is better!! I've tried various options from tagging additional 1000uF caps to the bottom of the PCB through to big Panasonic TSUP 10,000uF and 22,000uF on short wires with the caps glued to the back plate!! The caps I'm talking about are 2703, 2713, 2707 and 2711. You can try Panasonic FC which you may be able to up the uF and still fit into the space. If I was keeping the player, I'd go for the TSUP option with leads! If you want to, you can change the PSU diodes to schottky type. Something like 11DQ09 can be had for about 30p each. I wouldn't say diodes makes a significant difference on their own but they do add up in the big picture.
In this one, I used larger value FC's for 3 rails and a 22,000uF TSUP on leads for 2707. This is the most important one to go large with! These pics are of a Philips CD850MKI but the PSU is identical.
Additional caps under the board! (you can also see the yellow wires for the NOS mod bottom left and also links to bypass the muting circuit at the top).
Next is the output stage! Change the opamps! I like LME49720, very detailed and dynamic. Replace the local decoupling caps for the opamps too with Rubycon ZLH 470uF again (2670,2672,2674 & 2675). The last quick thing is the green Nichicon output caps, they are MUSE BP type. Replace these with MKP film caps 4.7uF or slightly bigger 6.8uF? I have used Mundorf MKP's here previously but Wima will be cheaper. If you want to go all "Boutique" here, you can. its worth it if you are going to push this player. Search ebay for Ampohm 4.7uF they are out of production but they are excellent value for money if you can find them! You could also link the output caps direct to the output sockets bypassing the muting circuits. If you do this, you'll also need to isolate the output socket centre pins from the PCB. Possibly a good time to replace the output sockets with something slightly more exotic??
In this one, I reused some elna Cerefine and some LME49720HA (tin hat version) just to see what it sounded like!! I also used Mundorf MKP's to replace the MUSE BP's
Finally you have the chips!, I would change the local decoupling caps (2654,2634,2653on TDA, 2632 on SAA7220 and 2607 on SAA7310) for the main 3 chips not to Panasonic FC as previously suggested(they are much better for PSU main smoothing before the regulators) but to ZLH again! The TDA needs all the micro detail teasing out so using softer sounding caps like Elna Silmic or Nichicon audio caps is not the ideal choice here. In anycase, the ZLH are much cheaper. I would use 470uF again. You can get 10 from RS in the UK for under £5.
Finally you can look to upgrade the clock!!! There are a few option including some OK ones from ebay. If you are up to it you could build your own "Flea" of you can go the whole hog and buy a commercial one!
This is a basic cheap clock I out in a CD50.
I wrote a clocking document based on everything I've learned here and my own experience. Its worth a look! I cant find where I hosted my copy but its available on the Fidelity audio website in their clock section. Fidelity Audio : Low Jitter C2 Premium clock Micro clock dual output for squeezeboxes
Last thing on the "to start with" list is the case! Its very flimsy! I used copper weights (were RAM coolers) and BluTak to add mass to the transport and dynamat to deaden the case.
Finally - well 1st really! A good quality reg for the 7220 - remove the supply resistor to the chip 3650. The output of the reg needs to go into the left hole where the resistor was. The supply to the reg comes from the cap 2707 (+&gnd) which hopefully you'll be swapping to a very large cap!! If you only ever buy 1 boutique low noise regulator, its here you need it! Watch out tho because most commercial audio regs wont output the current required for the 7220. One reg that can cope is the Audio Fidelity SPower. You can use the link from the clock document. You could also try building a LM317 based regulator here. There are few nice designs on the forum for this type of reg.
Final piece of advise, do one job at a time. Work slowly, check and double check each solder joint and connection before you power up each time.
This is only the start! There's plenty more you can do once you've got the hang of it!! Good Luck!
PS the CDM4 loading wheel is available on ebay! I've done a couple now¬
Couple of other points!
The SWB will do up to 630mA so you may not be able use it for the whole player in the position of the original 5v reg. You may be able to use 2. One for the SAA7220 (will need its own heatsink too) and one for the rest of the player (in the original position).
Also on the TDA bit decoupling, there are better options than the ones in the lampizator picture. EC Designs has some really usefull info on his NOS thread. Personally, I would use PPS caps like these!!! 1uF SMT PPS
Alot of good reading there, will read it in depth tonight, just read through it once now.
I'm going to keep the CD-60 and possibly the CD-50 too, using one of them together with a headphone amp in my bedroom.
I've ordered belt etc of ebay, and also VIMA MKS2 0,22uF/63V that I planned on using, not going to use the one in the pic from lampizator.
Quick question, the caps on the bottom of the PSU board, are they in parallell with the ones on top or a replacement?
|All times are GMT. The time now is 08:16 AM.|
Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 17.65%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio