Sony CDP302ES Digital Out & DAC mods

[Gary Indiana]

Hi Cizeta, great thread. What you did is fairly advanced.

Now, could you suggest a simple tap to an external DAC? Without adding and/or replacing too much in the original CDP302ES?

Thank you in advance.

 

[onwardjames]

Would that ever be nice!! If it can be done, Cizeta can do it.

 

[olecram]

Good morning cizeta. I have this same Sony CDP-302ES and has been using it for a while. I was planning on doing the mods you just mentioned if I can.. Do you need to solder the (3) parts you initially mentioned in your first thread or simply plug them in. I have zero knowledge in soldering. Let me know please. Thanks and all the best. Arthur.

I am a Sony engineer and I have a CDP302ES since 1986 (30 years old). By technical I had access to confidential technical publications of Sony and I have replaced, over the years, the chip CX23035 (signal processor) with the most modern CXD1125Q, (pin to pin perfectly compatible), which is equipped with digital output (pin 27- DOTX) and plugged two PCM56P-K instead of the CX20152 DAC, being unique for the two channels (UNI linear converter), working alternately causes a technically annoying delay of approximately 5.67 microseconds between the left channel and the right channel, eliminated by the two DACs separated. Its operation is still impeccable and the sound is at the highest levels of quality. Tried instrumentally far it exceeds the linearity and intermodulation distortion (CBS CD-1 TEST DISC track 13) of the current bitstream readers. The sound of PCM56P is recognized as excellent.

 

[olecram]

Hi everyone. Further to my previous inquiry above, I purchased (2) PCM56P-K DAC's. Upon opening up the CD player, I saw just (1) CX20152 DAC with 28 pins. I'm at a loss as to how to replace this with the the (2) PCM56P-K DAC's with 16 pins. Anyone in the know if you can please advise very much appreciated. I have very limited electronics know-how, pardon me. Thanks in advance. All the best. Arthur.

 

[cizeta]

Hi olecram, thanks for reading my thread. Unfortunately, the change you are referring to is very complex. We need to create a special printed circuit to house the two PCM65Ps and the two operational ones I used as external I / V converters. You can also skip this latest design subtlety and use the PCM65P internal converters. In my opinion it is easier to get a faulty reader using the two PCM65s as converters with little expense and to cut out the printed circuit for use on the 302ES.
This circuit must be correctly powered and interfaced between the digital filter of the SONY (CX23034) and the anti-image filter existing before the audio outputs of the 302ES (IC402-IC403-IC502-IC503). Keep in mind also that eliminating the CX20152 DAC the reference oscillation at 67.7376 MHz is missing, which, after division x4 becomes 16.9344 MHz and becomes the clock for the digital filter and for the rest of the control circuit. This 16.9344 MHz oscillator must be rebuilt. In the pictures of my story you will see this oscillator instead of the old CX20152 converter.
The operation is complex, but there is the possibility of using a double converter of the Philips TDA series that can be easily inserted instead of the old one with very limited modifications.
When the CX20152 is removed, a socket is integrated for integrated and then a craft circuit that hosts the double Philips DAC is built on a matrix board. The basic circuit should always be modified to offer the audio signal output from the Philips to the original Sony low pass filter. I made this change on another CDP302ES that I own, and the sound result is splendid. I have never posted this change, but if you are interested I can open this player and show you the changes, also accompanying them with photos. Thanks for your interest.

 

[cizeta]

Clearly also in this case the 16.9344 MHz oscillator must always be restored ...