Philips CD-Players of the first generation

The CD is dead - long live the CD!

Here I will share my 10 years of experience with the Philips CD-Players of the first generation. Step by step I will modify a CD104 in one of the best CD-Players in the world.

1. Stroke: Power Supply Print

With this modding, the player gets new juice. At least twice the reservoir capacitance of the original capacitors and even three times of the reservoir capacitance for the so important 5V digital supply.
Furthermore it gets a nickel-free mains socket to make the player safer and get rid of first weak design points. Also I will fix the fundamental audio theme called: ground loops. The ground of the casing is separated now from the signal-ground.
The old voltage regulators will be replaced by new and excellent regulators from ON Semiconductor.

  • fixes all ground loops in the supply section
  • disconnects the device ground from the signal ground
  • all ground connections soldered, not plugged
  • twice the capacitance for all supply rails
  • three times capacitance for 5V digital supply
  • including new voltage regulators from ON Semiconductor
  • high-grade audio-capacitors
  • high-grade audio-rectifiers
  • including Furutech mains socket
  • as DIY-kit with step-by-step instructions, sneak preview here
  • or ready built in your player

Prices
DIY-kit
EUR 150.-
Built in your Player
EUR 300.-





2. Stroke: Laser Print

Here I deal with the other end or more likely the beginning of the digital signal! The laser print houses the control for the laser diode on one hand. The laser has to emit light as constant as possible. On the other hand it comprises the amplifiers for the signal that is obtained by light interference. This signal splits into the actual data stream that is being demodulated to the digital signal and the tracking, focus and motor information that is being evaluated by the servo. A good summary of these complex operations is on Wikipedia or even more detailed here (german only).
When this tuning is performed, it is a good opportunity to clean the shaft of the drive and replace the platter bearing with Teflon. If you order "built in your player" I will clean the inner lenses of the laser stock (this cleaning is necessary due to after 35 years some debris has fallen through the gap of the moving focus lens). Also included is the exact perpendicular adjustment of the azimuth of the RAFOC-unit and its axial bearing clearance.

  • separate ground rails for the laser and the sampled data
  • precision trimming potentiometer for the laser supply
  • correction of the original print regarding power supply
  • 3-times capacitance for this power supply
  • better op-amp for the servo-signals
  • high-grade audio-capacitors
  • low-noise transistors and resistors for the hf-amplifier
  • Teflon platter bearing
  • as DIY-kit with step-by-step instructions, sneak preview here
  • or ready built in your player incl. cleaning of the inner laser lenses
    and adjustment of the azimuth

Prices
DIY-kit
EUR 150.-
Built in your player
EUR 350.-





3. Stroke: Servo Print and Output Stage

The servo print is a quite complex circuit. At the latest here arises the question: why new prints? In my opinion there are three good reasons.
On the one hand the prints are, depending on the external circumstances of the last 35 years, exhausted. In some devices solder pads peel off by just looking at them. And the copper side of the pcb tends to become a semiconductor. They are staring literally towards death. The pcb material of today pledges easily another 35 years.
On the other hand every single component in a high-end device will leave its acoustic signature! No matter where it is. That makes sense due to the fact there is only one common ground and the output stage and the servo and all other modules have to share the same supply voltages. To get rid of all suboptimal sounding components (e.g. ceramic capacitors) there is a lot of solderwork ahead. Or new circuit prints!
The third good reason is the possible higher integration of the circuit. This gives way for additional components, e.g. to stabilise the supplies. And it gives way for the new output stage on the servo board.
There is a fourth reason I will explain later.

  • separate ground rails for servo and outputstage
  • lots of capacitance for all ICs
  • ultrafast WIMA FKP-caps to decouple the digital components
  • high-grade audio-capacitors and resistors
  • no solder mask on the output stage area
  • outputstage with high-end op-amps
  • Rhopoint wire-wound resistors for the I/V conversion
  • incl. Rike-Audio S-Cap decoupling-cap
  • as DIY-kit with comprehensive instructions
  • or ready built in your player

Prices
DIY-kit
EUR 350.-
Built in your player
EUR 600.-
optionally 2x WBT
RCA socket
nextgen Ag
+ EUR 90.-





4. Stroke: Decoder Print

The decoder print demodulates the HF-signal and brings it in a format that can be transformed in an analog signal by a DAC. But first it passes an error correction chip with appended data storage. These chips also create the drive speed.
As its name implies, there are digital processes taking place on the decoder print. These processes have very specific demands regarding power supplies. Thus digital impulses have very high slew rates, with an inadequate decoupling voltage drops in the supply rails are inevitable. To prevent from this, I have installed PowerPacks for every single IC and every supply voltage.
Of course this PowerPack is also used for the ultra precise lowjitter TentLabs Masterclock with it's separate supply voltage.
Before the digital signals enter the TDA1540 DAC, they pass a circuit to attenuate themself by 50%. Attenuating sounds negative at first, but this added circuit brings a less stressfull sound quality, due to less crosstalk from digital to analog parts in the DAC.
I have relocated the IC for the negative 18V reference voltage for the TDA1540 from the power supply print to the decoder print. The 5V digital supply for the DACs becomes its own supply rail to the print.
All parts left / right are paired for maximum channel equality.
The Oversampling IC SAA7030 of course does not find a place on the new board. The player is now switched to non oversampling mode.

  • separate ground rails for decoder and DACs
  • PowerPacks for all supply voltages and all ICs
  • high-grade audio-capacitors and resistors
  • no solder mask on the DAC stage area
  • attenuation for the digital signals
  • from DAC on all parts paired left / right
  • negative 18V supply voltage relocated
  • ultraprecise lowjitter TentLabs Masterclock
  • NOS: Non-Oversampling Mode
  • as DIY-kit with comprehensive instructions
  • or ready built in your player

Prices
DIY-kit
EUR 300.-
Built in your player
EUR 500.-

all 4 in one stroke
built in your player
EUR 1,700.-





5. Stroke: DC Mains Filter

The topic "DC in mains supply" came up while dealing with a phono amp project. Indeed our mains is pure AC in very few cases. Certain consumers generate a zero offset, thus dc-current can flow when equipment is connected. Best example is a hair dryer on "switch position 1". The built in rectifier that throttles performance lets through only one half wave. Problem is, that transformers don't like DC at all due to the core gets premagnetized. With a tight design or a high DC current flowing, the transformer comes into saturation which can be noticed by sporadic humming. Then in High-End Audio it's too late anyway! Relief provides a capacitor which is connect in series(!) in one of the supply lines. Phase or Neutral doesn't matter. The "decoupling-capacitor" blocks all dc current. Some provide a film foil cap in parallel with the electrolytic cap. I deliberately omit this film foil cap and let the electrolytic cap block some of the high frequency debris too!

  • 3,100 μF capacity: voltage drop at the cap is 0.15 V
  • six antiparallel rectifiers enable a spacious operating area
  • mains fuse on board
  • as DIY-kit with instructions
  • or ready built in your player

Prices
DIY-kit
EUR 50.-
Built in your player
EUR 50.-


More about the topic Philips CD player:

Here the original CD 104 Service Manual. (5.5MB!)

nanocamp offers information on the topic "maintaining the CDM-1 drive" (german only).






CD - Tweaks

Some things get stuck with you. In High-End Audio and the rest of your live this is a clear sign that something is working. Here are some tweaks for better CD-sound:

CD washing machine

CDs are clean, when freshly bought ... or not? Since years I use the CD washer "Hydrobath 1120". Here little Youtube-video how this works.

Blacken the CD edge

All you need is a black Edding 500 or similar waterproof felt tip. If you want to take it exactly, you can also blacken the blank area on the outside which can be easy observed under some LED-lamps.

CD-mat

to be placed on top of the CD ... I use this one.

CD cryo-treated

Cryo treatment doesn't only work with metal. Also other materials "relax" when deep temperature treated. It works also with CDs due to they are read optically and thus refraction of light in the CD medium is of importance. Who doesn't believe it can burn two identical CDs and send one to George Forester who will cryo-treat it for free!

Chamfer CD edge

The idea is old: Due to the information on a CD is read by laser and the principle of interference, it is a good idea, to reduce stray light as much as possible. Audiodesksysteme Glaess once offered such a device to chamfer the edge of the CD in a certain angle to reduce flare. This had the positive side effect, that the CD was also balanced after procedure.

During my research, I found another (and cheaper) method of reworking CDs. Originally posted by Volker Bajorat of Clockwork Audio. Here is the instructions (german only).