[deuginthesky]

Hello all and happy new year !



SAA7345GP has a very poor bandwith, people say the CD711/721 should sound much better without.

But how can I get the signal without it ? Is it possible to get a NOS CD721 ?

SAA7345 schematics.
http://matthieu.benoit.free.fr/cros...ets/SAA7345.pdf


Thanks !

 

[cetoole]

Bad URL, seems to have gotten truncated. Try: this
At a guess, it doesnt seem to be just a digital filter, but perform many critical applications in the CDP, such that removing it will cause your player to cease functioning.

 

[deuginthesky]

Is there any way to deactivate the oversampling ?

 

[luvdunhill]

yes. Look at tapping into the i2s signal directly and feed that to a NOS DAC.

 

[cetoole]

Quote:

Originally Posted by deuginthesky /img/forum/go_quote.gif Is there any way to deactivate the oversampling ?

Yup, looks doable. All you gotta do is look at table 2 on page 6, find the DAC Output register section, determine which mode you are currently in, and change it to the appropriate fs mode. You probably will need to reprogram that section of the uC to 1110, or maybe 0110, depending on if you need i²s or eiaj. Then, since changing the OS will change the analog output, you will want to change the analog low pass filter parts' values to more appropriate ones for 0fs.

Luvdunhill, if he taps the data output right now (whether it be i²s or eiaj), it will already be oversampled data he is getting. Remember, the digital filter is part of this IC, so the current DAC in his player is just tapping the output, but doing no oversampling by itself.

 

[deuginthesky]

Quote:

Originally Posted by luvdunhill /img/forum/go_quote.gif yes. Look at tapping into the i2s signal directly and feed that to a NOS DAC.

Rather than an NOS DAC, I would like to try an tube output stage, as people here know, there are schematics for ECC88 output on the web. Althoug the schematics is for CD723, the CD721 also runs a TDA1545A (SOIC version).
CDM12 mechnics is better than the Eco SL of the CD723, may be the overall result will also be better.

But 1st, I would like top get rid of the SAA bad oversampling.

Thanks for the support guys.

 

[deuginthesky]

How to replace the laser pick-up assembly of your CD player

Would cut the connexions as on the picture make the job to get a NOS TDA1545A player ?

 

[Malefoda]

A bit old, but someone has removed this IC? I fried one and need to source this precious thing...
PM' me if any deal in sight...