Hi,
I have a Philips CD650 which holds a regular TD1541 DAC chip
I also own a Philips CD582 which holds a TD1541A chip
Would it be worthwhile to remove the 1541A chip from the CD582 and move it into the CD650 ?
I.e. will this improve the sound quality of the CD650 in a noticeable manner ?
Thanks,
Bart
I have a Philips CD650 which holds a regular TD1541 DAC chip
I also own a Philips CD582 which holds a TD1541A chip
Would it be worthwhile to remove the 1541A chip from the CD582 and move it into the CD650 ?
I.e. will this improve the sound quality of the CD650 in a noticeable manner ?
Thanks,
Bart
Well, inthe CD650 I am replacing all el. capacitors and replace the 2 opamps ne5532 with opa2134 (sockets so can be undone). Would it then be worthwhile to insert the A chip ?
Regards,
Bart
No, you can use TDA1541A and SAA7220P/A together. The SAA7220P/B is an improved version.
http://www.dutchaudioclassics.nl/type_differences_saa7220p_a_b_c/
I also believed for long that TDA1541 and SAA7220P/A are a combo just as TDA1541A and SAA7220P/B but they are interchangeable. I think it was Rbroer who corrected me long ago. Maybe you can use the Search function to find it.
BTW TDA1541A is better than TDA1541 but of course there are other people claiming the opposite.
http://www.dutchaudioclassics.nl/Philips-TDA1541_A-Monolithic-Dual-16-Bit-D-A-Converter/
http://www.dutchaudioclassics.nl/type_differences_saa7220p_a_b_c/
I also believed for long that TDA1541 and SAA7220P/A are a combo just as TDA1541A and SAA7220P/B but they are interchangeable. I think it was Rbroer who corrected me long ago. Maybe you can use the Search function to find it.
BTW TDA1541A is better than TDA1541 but of course there are other people claiming the opposite.
http://www.dutchaudioclassics.nl/Philips-TDA1541_A-Monolithic-Dual-16-Bit-D-A-Converter/
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There are a number of mods that are quite easy to do.
Change DEM cap to a value that "locks", swap the tda's decoupling caps to film caps, put in a nos/re-clocking module(can be found on ebay) or provide the saa7220 with it's own regulator. I have not tried the nos/re-clocking module, but heard good things about it.
It all comes down to how much time, effort and money you are willing to spend I guess.
Change DEM cap to a value that "locks", swap the tda's decoupling caps to film caps, put in a nos/re-clocking module(can be found on ebay) or provide the saa7220 with it's own regulator. I have not tried the nos/re-clocking module, but heard good things about it.
It all comes down to how much time, effort and money you are willing to spend I guess.
The clock is originating in the SAA7220, therefore that is one of the most critical cips for jitter generation.
The SAA7220P/B has better ROM coeficients and better jitter characteristics. Also the offset of 5% provided by the SAA7220P/A (necessary for TDA1541) is now reduced to 0.05% for TDA1541A, therefore eliminating the full-scale distortions.
There is no point of adding a better clock to a SAA7220P/A, because it will degrade the clock regardless...
Better power supply - yes (if original one is not sufficient). Usually on old CD players, the PS are not sufficient anymore because filtering capacitros are old and dry out. Just replacing those usually makes a big improvement. No need for fancyer work IMO.
The SAA7220P/B has better ROM coeficients and better jitter characteristics. Also the offset of 5% provided by the SAA7220P/A (necessary for TDA1541) is now reduced to 0.05% for TDA1541A, therefore eliminating the full-scale distortions.
There is no point of adding a better clock to a SAA7220P/A, because it will degrade the clock regardless...
Better power supply - yes (if original one is not sufficient). Usually on old CD players, the PS are not sufficient anymore because filtering capacitros are old and dry out. Just replacing those usually makes a big improvement. No need for fancyer work IMO.
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Well dear Sonic, while you weren't probably even born I was already modding Philips based cdplayers . Internet was non existent and we had to discover things by doing. I can tell a better clock will make a difference but SAA7220 still is a polluting chip, that is right. That won't change but after having modded tens of CD80's I can tell a better clock is eh ... a better clock. SAA7220 is a current eating bipolar chip that needs a separate supply to lessen its influence on the total outcome. It can easily be observed on a simple oscilloscope what better decoupling does for the SAA7220. It can also be removed altogether but after having see you performing in another thread on the non OS matter I will not even attempt to go there. Thanks for copying the info out of the links I gave myself. Replacing all electrolytic caps on 30 year old equipment is not a matter of choice but a necessity.
Since you started posting more frequently on diyaudio atmosphere has changed for the worse. It seems you are always in for a conflict. There are no weapons of mass destruction on diyaudio.com !
Since you started posting more frequently on diyaudio atmosphere has changed for the worse. It seems you are always in for a conflict. There are no weapons of mass destruction on diyaudio.com !
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It has no sense to judge things from a predetermined perspective.
A Tent module will cost 29 Euro and a simple power supply will set you back 10 Euro. You will have one of the best clocks available for a low price. Results will be quite extreme in some cases, it is absolutely worth the money.
A Tent module will cost 29 Euro and a simple power supply will set you back 10 Euro. You will have one of the best clocks available for a low price. Results will be quite extreme in some cases, it is absolutely worth the money.
God I wish you would build things in reality instead of debating with a keyboard. I compared the Fox in 24.576 MHz fed with a FleaDIY set up for 3.3 V with the 24.576 Tent XO module fed by a FleaDIY power supply (also set up for 3.3 V) and the Tent performed better. Not a very large margin but it simply was better. Have to admit that the Tent does a better job on 5 V. Fox oscillators are way cheaper. I use them when budget is tight. They have a newer type that is even better on paper but I can not get hold of it here. Note : this test was not in a SAA/TDA based machine.
I used a large number of Tent XO 11.286 MHz modules in various Philips based cdplayers in the past and had very good results. Any of these 2 combined with a FleaDIY board (www.raylectronics.nl look for PFM Flea at the left side) will let SAA7220 based cdplayers to a higher level for very little money. The FleaDIY is my "Geheimtipp" anyway. It does not cost an arm and a leg and Tent XO and SMD 7 x 5 oscillators can both be used. Very low noise, very small, it can be configured for 3.3 V and 5 V and it is very well performing.
But this all will take more time than simply typing an opinion.
Bart1968, please find another new TDA1541A instead of reusing the current one. Then you will have 2 cdplayers that work
If you like the cdplayer you can make it a very good sounding machine if you start with the basic stuff like cap replacement, opamp change and a better clock. I would also remove the muting transistors and feed both the SAA and the new clock with a small separate transformer + power supply.
I used a large number of Tent XO 11.286 MHz modules in various Philips based cdplayers in the past and had very good results. Any of these 2 combined with a FleaDIY board (www.raylectronics.nl look for PFM Flea at the left side) will let SAA7220 based cdplayers to a higher level for very little money. The FleaDIY is my "Geheimtipp" anyway. It does not cost an arm and a leg and Tent XO and SMD 7 x 5 oscillators can both be used. Very low noise, very small, it can be configured for 3.3 V and 5 V and it is very well performing.
But this all will take more time than simply typing an opinion.
Bart1968, please find another new TDA1541A instead of reusing the current one. Then you will have 2 cdplayers that work
If you like the cdplayer you can make it a very good sounding machine if you start with the basic stuff like cap replacement, opamp change and a better clock. I would also remove the muting transistors and feed both the SAA and the new clock with a small separate transformer + power supply.
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I think, you mean probably a separate power supply for the clock module and not for the SAA7220 itself.
But now the question raises up, whether an additional separate power supply for the SAA7220 is also helpful to improve the sonic results additional.
It probably does but I do not know if the difference is large enough to justify the extra transformer
What I do mean is the following: a small 15 V 5 VA toroid with a diode bridge + cap for the clock (a FleaDIY is already a low noise PSU) so that the only GND connection of the clock will be at the SAA's clock input GND. Please not that the FleaDIY needs a realitively high input voltage !!!! Otherwise one could use a standard transformer with one winding for the SAA and one for the clock. Too bad this will not be possible unless one uses a transformer with different secondary windings of let's say 1 x 7 V 0.5 A and 1 x 15 V 0.1 A.
Secondly a dedicated 5V well decoupled regulator for the SAA. So the SAA will not be fed with the main 5 V line while polluting the very same 5 V power line. So at least an extra 7805 between the SAA and the primary side of the 7805 of the mainboard..
I hope it is clear now.
What I do mean is the following: a small 15 V 5 VA toroid with a diode bridge + cap for the clock (a FleaDIY is already a low noise PSU) so that the only GND connection of the clock will be at the SAA's clock input GND. Please not that the FleaDIY needs a realitively high input voltage !!!! Otherwise one could use a standard transformer with one winding for the SAA and one for the clock. Too bad this will not be possible unless one uses a transformer with different secondary windings of let's say 1 x 7 V 0.5 A and 1 x 15 V 0.1 A.
Secondly a dedicated 5V well decoupled regulator for the SAA. So the SAA will not be fed with the main 5 V line while polluting the very same 5 V power line. So at least an extra 7805 between the SAA and the primary side of the 7805 of the mainboard..
I hope it is clear now.
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I also found that SAA7220A and SAA7220B are both compatible to TDA1541 and TDA1541A, but see my bit transition measurements:
http://www.diyaudio.com/forums/digital-source/113620-dac-linearity-test-cd-4.html#post1443116
See also post #44 in the same thread.
Note that pin4 is used for some reclocking in TDA1541, but it is not used in TDA1541A (at least I could not find any evidence that it is used).
http://www.diyaudio.com/forums/digital-source/113620-dac-linearity-test-cd-4.html#post1443116
See also post #44 in the same thread.
Note that pin4 is used for some reclocking in TDA1541, but it is not used in TDA1541A (at least I could not find any evidence that it is used).
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