CD-753 - only for seasoned modders

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I just bought a Philips CD-753 cheaply on ebay, mainly for the CD-text option.

I was surprised to find that only one out of 15 current CDs I tried had CD-text.

The sound of the CD player is best described as mellow. It is pleasing, and nothing is really wrong. Switching back to my player with external clock and AD1854, this sounds cold for the first couple of seconds, then one begins to realize how much more detail there is.

Then I took the CD-753 apart. TDA1459 DAC, an early multilevel sigma-delta DAC with 4xfs input, nothing special. SAA7378 processor. Problem here: they used the internal 4x oversampling filter. It is so bad they don't even give performance data or graphs in the data sheet, but going back to the 7345, you can see how poor it is (talk about 40 dB stop band suppresion).

One thing that the CD-753 does better than older Philips players: there is only one master crystal sitting next to the processor. There used to be up to three crystals or resonators on the CD board alone, plus one for the user processor.

The power supply scheme is minimalist. The bean counters were very clearly at work.

If you want to mod this player, the DAC is beyond hope. You would want to improve the digital and servo power supply, use an external clock and somehow feed the digital data to a new DAC. This must be done through a DIR chip because there seems to be no access to the non-oversampled data.