good dac tweak

[pabiz]

I'm an italian new member and I'm looking for the best way to tweak the dac of my old Rotel 965BX.
This player have a philips 7310 as servodrive,saa7220 as digital filter and saa7323 as dac.
have anyone some idea schematics or experience about this player modification?
Thank you and sorry for my bad english

[aparatusonitus]

Hi pabis,

The simplest mod you can do is to put your cd player in nonoversampling filterless mode in order to get "clean" I2S digital format for a dac. Everything is well explaned here:

http://xoomer.virgilio.it/hi_fi/

Next thing you should do is to build dac with TDA1543 or TDA1541A of course...

[pabiz]

Thank youfor your replay I have consider it but I'm not sure for the result,this modification is irreversible.
I have think the possibility of I2s direct the saa7323 have this output but I don't have any schematics.

[aparatusonitus]

This mod is reversibile, you can always solder those three lines together again. I have a SAA7322/7323 datasheet, so if you need one send me a PM with your mail.

[Rotellian]

This mod will not work for the SAA7323 as it is a bitstream dac. The oversampling is required to get the dac to actually work. The non OS mod is only suitable for multibit players that use chips such as the TDA1541a.

[aparatusonitus]

I guess you are right , so next thing cames in to play...

[pabiz]

I have the datasheet of saa 7323 it has an internal oversampling filter infact it isn't bypassable.
The only modify possible is to get directly the I2s format out of 7310 pin37-38-39 or from the saa7323 output pin19-20-21so I need an I2s dac,I think.
Have you any good schematics?

[aparatusonitus]

Out of hand, same usefull information you can find here:

http://www.tnt-audio.com/clinica/statosolido.html

http://www.dddac.de/

http://users.verat.net/~pedjarogic/audio/

And search this forum a bit, of course...

[mb]

My experience with a couple of the bitstream Philips players is that the "usual" mods will work wonders -- schottky diodes to power supply, improved capacitors, better dc blocking caps, etc, etc. The most dramatic improvements I experienced were from making sure that the power and power bypass caps to the dac chip (SAA7350 in my case) were improved. Better opamps, and class A opamp bias also help, but not as much as making sure power to the dac is robust and clean.

[Fin]

Hi

I'm working on a CD624 with 7310 and 7321(older version on 7323). Let me know if you are still interested in some possible mods.

There is also a current discussion on the QED Digit with similar dac at:
http://www.diyaudio.com/forums/showt...827#post392827