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Philips CD104 Non Oversampling Modification
 
 

  I will not write about the Philips' CD players sound qualities from the first generation (1982, 1983 and 1984 as CD100, CD101, CD104, CD204 a.s.o). They are great and why, you can read on other webs. I personally use a CD303 (my preferred model) and a CD104 with NOS (non-oversampling) mod.

  Why oversampling seems to be bad will not be discussed here. And you should also look up other sources to see what should be carried out in any of the mentioned models (as resoldering some connectors on the PCBs or checking the filter and voltage doubler caps).

  But here is a short manual how to eliminate the oversampling from the unit.

 

  BTW: Oversampling can be removed from many later CD players, but these Philips models have other outstanding qualities (as the incredible CDM1 and CDM0 transports...)

 
 

 

 

 

 
    Philips CD100 CD200 CD101 CD 104 CD204 CD304 CD 100 104 nos non oversampling mod modification SAA7030 TDA1540  
 

 

 

 

 
   

All above mentioned units use separate ICs for signal processing: from the laser to the

- SAA7010 Demodulator

  (separates clock and data) to the

- SAA7030 Error correction

  (error detection and correction) to the

-  SAA7000 Concealment and Interpolation

  (separates L + R, audio correction) to the

-  SAA7030 Digital Filter

  (Oversampler) to the

- TDA1540 DAC Digital Analog Converter

  (one per channel) and finally into the

analogue output stage (NE5532).

(I found all data sheets on the web)

 
 
  Philips CD100 CD200 CD101 CD 104 CD204 CD304 CD 100 104 nos non oversampling mod modification SAA7030 TDA1540  

The non oversampling (NOS) mod:

1. As we do not longer need the overs-

  ampling circuit (SAA7030) just remove it.

2. Pass the data:

  - wire bridge from pin 20 - pin 3 (left)

  - wire bridge from pin 17 - pin 10 (right)

3. Pass the clock and the strobe

  - wire bridge from pin 21 - pin 7 (strobe)

  - wire bridge from pin 18 - pin 6 (clock)

  Now the outputs of the SAA7000 (pin 13 is left and pin 15 is right) are directly connected to the input pins of the TDA1540 DACs (pin 1 on each).

The first Klangfilm cables in a digital design!!!

 
 
   

4. As the TDA1540 only understands 14 Bit data streams, the SAA7000 has to be wired for 14-Bit-operation. This can be selected on pin 16. If it is low (0V) the SAA7000 works in 16Bit-mode. So cut the printed circuit lead to pin 16 (scratch it from the PCB) and give it 5V by adding a resistor (from 1k to 5k) to pin 18 (which is at 5V).

  That's all! Give this a try....

  Take the opportunity to install good RCA jacks (soldered cables are great, but this cable is bad...). And check the voltages on the 1540: about 3.8V on pin 4, -5V on pin 7 and -18V on pin 11. If not, check the PS!

 
 

 

 

 

 
     
 

 

 

 

 
    Philips CD100 CD200 CD101 CD 104 CD204 CD304 CD 100 104 nos non oversampling mod modification SAA7030 TDA1540  
 
 

 

 
 

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