Building the ultimate NOS DAC using TDA1541A

Hans Polak

If you are here, could I persuade you to make some .wav files with 1 kHz -40 -50 -60 dB?
The reason for this is that I have found that there is much difference between the .wav files I have downloaded from the net. And the files you have made with -90,32 dB is the cleanest I have seen 😛
In this thread I am measuring a No Dac direct DSD and here the results are even more different than in the TDA1541A.
https://www.diyaudio.com/forums/digital-line-level/273474-dac-dac-198.html#post5781371
 
Hans Polak

If you are here, could I persuade you to make some .wav files with 1 kHz -40 -50 -60 dB?
The reason for this is that I have found that there is much difference between the .wav files I have downloaded from the net. And the files you have made with -90,32 dB is the cleanest I have seen 😛
In this thread I am measuring a No Dac direct DSD and here the results are even more different than in the TDA1541A.
https://www.diyaudio.com/forums/digital-line-level/273474-dac-dac-198.html#post5781371
How long should the be in seconds.

Hans
 
Koldby,

I looked at the three files to see that they are all three shifted by 20dB, so 40 is -20dB, 50 is -30 dB and 60 is -40 dB, a silly mistake that I made.
Can you please confirm this before I make the -50 and -60dB, because your feedback seems a bit strange.


Hans
 
In John’s original 50hz DeM schematic with 1x tda1541a and in his comment below he gives 1uf for the oscillator cap - but in his schematic for 2x tda1541a which is attached to the post I am replying to and despite what he indicates in the text, the value in the schematic is given as 2.2uf

So does the value of this cap change if you use 1 or 2 chips?

Hi sumotan,



!00uF/25V caps, plus (+) connects to GND (0V). Minus connects to the pin of the TDA1541A.

Reason: the DC voltage on the 14 TDA1541A decoupling pins is negative (-12 ... -14V typical) with respect to GND.

1uF film cap between pins 16 & 17, 12K resistor between pin 15 and pin 17.

See attached schematic.
 
In John’s original 50hz DeM schematic with 1x tda1541a and in his comment below he gives 1uf for the oscillator cap - but in his schematic for 2x tda1541a which is attached to the post I am replying to and despite what he indicates in the text, the value in the schematic is given as 2.2uf

So does the value of this cap change if you use 1 or 2 chips?

No, use what you have by hand. Either value will do it.
 
So story ends here .. I am so sorry to hear your board is dead now. I can tell you ryanj's board is working well and not that difficult to solder.I am a -52 vintage, so my eyes and hands are not what they used to be either. Remember to buy the right parts in the correct housing ( I got some of the IC's in a smaller package first time around)
For others , who wants to correct Ians board: Invert the CLK out of Ians board to TDA1541A, disconnect the LE out from Ians board and connect the LE input on the TDA1541a board to the WS input on Ians board (in parallel with the cable from i2s source to Ians board) . Data input and DL and DR is not changed.

Sorry to revive an old post - but I’ve bought an inverter and plan to make the bck mod/fix. Will checkout the LE issue if I’m successful with bck.

Thanks for all the previous discussion on this.