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My cd player is a Pioneer PD-S603. It's a nice mid-fi player, which features Pioneers Stable Platter mechanism and the Legato link DAC. It sounds pretty well and the player has served me well over the years that I own it.
I found some information on the web on how to improve the sound of Cd-Players in an easy way. And I chose to replace the output opamps and to install a XO-clock
The first modification that I did was to install the XO-clock. The Xo-clock is a low jitter crystal that replaces the players original crystal. You can find info on how to order your own XO here. Scroll down to see the cd player upgrade section.
The XO needs a very stable at 5volts and I built the supply that Cuno features on his site. You can view the schematic here
I built this on a small piece of prototype board. Here´s a close-up of the circuit installed in my cd player. It works, but the layout is very poor, which had some unwanted side effects; read on...
Altough the use of tape and the way it is put in looks rather flimsy, it sits very secure and there is a foam pad between the back of the board and the metal housing of the player.
Here is an overview of the insides of the player. On the extreme left you can see the XO board and on the right you can see the transformer that I added, including the recitifier and capacitor.
Ok then, what were the side effects of my poor job on the circuit layout? Well, I found out by coincidence that the XO I installed was responsible of heavy distortion on a few channels on the television. The cd player is placed below the tv, in the small cabinet that I have. This distortion was visible as diagonal lines slowly wandering across the screen. At first I tought it was just the reception, but when I watched TV without the cdplayer plugged in (it was on my bench for tinkering), the distortion was gone. A few experiments later, it was clear that somehow there was severe RF transmitted from the powercord. A ferrite ring around the powercord cured a lot, but eventually I decided to take out the XO and reinstall the original clock crystal.
This was temmporary of course, as I had plans to do a better job on the circuit layout in a future date. Since I found out that PCB making is relatively easy, I decided to design a small PCB myself, for the XO clock.
Here it is:
 
I tested it, and it works fine. If you decide to make your own PCB, print the graphic on a 600dpi setting, that way the size will be correct.
This is the latest version of my XO-pcb. My previous one also disturbed my tv-reception quite heavily. This one leaves my tv-reception alone. Very nice... C5 from the schematic is left out of this PCB, I emailed G. Tent about this, and he told me that it isn't necessary.
Here is an image of the PCB, complete with components
I mounted this in my cdplayer with one of those blue PCB mounting thingies (L-shaped bracket). Works fine, and it is easy and reliable. Components are also much neater layed out on this board, compared with my previous one. That probably helps a lot with limiting the HF radiated from the board.
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