Philips CD721 player DAC

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Transport.

Thanks Massimo.

If the transport is the CDM12.1 and is reliable I am unlucky. I have a CDM12.1 in my Marantz CD67SE which died after about 20 hours of use. The disc does not rotate.
Ocassionally after pushing the front panel buttons randomly, it will suddenly start to play. Sometimes one or two CD's and then suddenly stop while playing a CD. Strangely the disc rotates in the opposite direction after a 1 sec correct direction start when in the service mode. I feel the transport is OK but something is wrong with the control. What can you guess?
Thanks.
Ashok.
 
Re: Transport.

ashok said:
Thanks Massimo.

If the transport is the CDM12.1 and is reliable I am unlucky. I have a CDM12.1 in my Marantz CD67SE which died after about 20 hours of use. The disc does not rotate.
Ocassionally after pushing the front panel buttons randomly, it will suddenly start to play. Sometimes one or two CD's and then suddenly stop while playing a CD. Strangely the disc rotates in the opposite direction after a 1 sec correct direction start when in the service mode. I feel the transport is OK but something is wrong with the control. What can you guess?
Thanks.
Ashok.

First of all, I was wrong. The above description belongs to the Philips CD 723, not 721. I guess the 721 was and earlier model, thus MAYBE it is using the Short Loader Mk II (with ceramic resonator and not a quartz and no capability to read CD-RW).
The DAC could be the same anyway.

From what you describe, I think the fault could be everything BUT the CDM12.1, but I cannot tell you what is broken.
Sorry.
 
The DAC in the 721 is reasonable (but not good), but 4x oversampling is done inside the decoder and it is done VERY BADLY (look at stop band attenuation in the SAA7345 data sheet). Unfortunately, oversampling cannot be switched off without changing the uC, so the only way to get a single f_s data stream is to hardware activate the SPDIF output and use a decoder.

It has a ceramic resonator, which is one of the first modding targets.

I have one sitting in a room where it is not used a whole lot. It is beginning to skip on virtually all CD-Rs which it did not use to do. Also, the drive always was pretty noisy (tracking noise).
 
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