Reading the tda1541 datasheet last night I finally clicked I think on what the simutaneous mode is. From what I understand the chip can be fed by offset binary or twos complement dependant on the voltage applied to one of the pins, either -5v,0v or +5v. Simutaneous mode is -5v?
And Ians board separates these and then DL and DR go to their independant input pins?
Is that correct? Is that the mode you are using
And Ians board separates these and then DL and DR go to their independant input pins?
Is that correct? Is that the mode you are using
Note here, the datasheet talks about input modes, Pin 27 needs to be at -5V or VDD1 potential to allow simultaneous mode. It also shows the DL, DR, BCK and LE pin connections.
Hope this helps and you get it running! Report back your thoughts!
Cheers,
Drew.
Hope this helps and you get it running! Report back your thoughts!
Cheers,
Drew.
Attachments
cheers Drew,
many thanks for your hint! I think I simply missed pin27
Will check once come home.Look into Signalyst.. He's got oversampling algorithm's that rival the best. And he is continually updating support and upgrades, recently went to 80bit precision for minimal resolution loss digital volume control and upsampling! If he had HDCD decoding for the M$ version it would be perfect. This is the future, and made possible by your project, thanks again.
And for Mac users, I give the highest recommendation to Audirvana Plus. It uses the excellent iZotope SRC engine and allows for full customization of all digital filter parameters. It will recognize USB DAC up to 768KHz, and also supports DSD in several modes (native, DoP, DSD>PCM). Wonderful sound and easy to use!
Did you switch TDA1541A to simultaneous mode by jumping pin 27 to -5V?
PCM interface is different from I2S interface.
Just hope it helps to solve your issue.
Regards,
Ian
hi Ian,
thanks! just have switched it as it should be and thought that the problem has been found and solved, but unfortunately same distortions still persist.
hi Ian,
thanks! just have switched it as it should be and thought that the problem has been found and solved, but unfortunately same distortions still persist.
Did you try the normal connection without the diode?
I suggest you asking for advise from Oliver to see what he get back to you.
I have his red PCB, but I still have no time to test it.
Regards,
Ian
Clock & Signal Terminations
Hi Ian,
2 questions I hope you (or some other seasoned expert of the many on this forum) have time to answer...thanks!
Are there any specific termination / load requirements for the output signals (clock,data) of the I2S to PCM board, on the DAC PCB I am laying out? This would be in single or dual differential mono mode.
Also, I asked this in the GB forum, but for correctness, will as k it here:
Is there a significant difference (by you or reported) in actual (or perceived) sound in using the I2S to PCM PCB, over the original version FIFO and re-clock PCB? (as I have now)
This would be with respect to the TDA1541 running NOS.
Regards,
Gary
Hi Ian,
2 questions I hope you (or some other seasoned expert of the many on this forum) have time to answer...thanks!
Are there any specific termination / load requirements for the output signals (clock,data) of the I2S to PCM board, on the DAC PCB I am laying out? This would be in single or dual differential mono mode.
Also, I asked this in the GB forum, but for correctness, will as k it here:
Is there a significant difference (by you or reported) in actual (or perceived) sound in using the I2S to PCM PCB, over the original version FIFO and re-clock PCB? (as I have now)
This would be with respect to the TDA1541 running NOS.
Regards,
Gary
Hi Gary,
1. You don't need any additional termination on all signals, because all signals were source terminated and matching 50 ohm impedance cable or trace
2. PCM borad was designed for many multi-bit DACs which do not accept I2S signals. PCM board does not have jitter elimination function as a FIFO does. So, if it works together with a FIFO and good clocks, the sound quality would be better .
TDA1541 can accept both I2S signal and PCM signal, however some diyAudio members and I confirmed that it sound better with driven by PCM signals .
Regards,
Ian
Hi Ian,
Thanks! I absolutely meant when the PCM daughter board is connected with the FIFO, and not just by itself with an I2S source. I understand the functioning of each board, no issue there. The question was answered by the last line of your reply. On this build, going with the AD1865N-K. TDA1541 running fine.
Gary
Cheers Ian,
removed the diodes, check all TDA's power supplies, made a mod to Oliver's dac (DEM oscillator), unfortunately the sound is still distorted.
Do you have any ideas what else could be checked?
Attachments
Thank clivem for your great news. With the PCM board, it would be more flexibility to play with different multi-bit DAC configurations. Keep going with your good job and let me know for your progress. Enjoy your music
.Regards,
Ian
Hi deses,
Did Oliver get back to your with some advise? I didn't find problem from your pictures. Just hope I can see the waveform which could tell exactly what was wrong.
If it would be any help, I can sent a new PCM board to you to confirm they are good.
Is there any suggestion from anyone else?
Regards,
Ian
Just in case there is any help:
http://www.diyaudio.com/forums/digi...rsal-i2s-pcm-driver-board-53.html#post3621653
Ian
we just rechecked the connection with TPA transceiver board and it turned out to be correct. I decided to try another spdif board that should come soon.
Meanwhile I was trying to connect PCM board with Amanero and got the same results. I doubt there is something wrong with your board, but anyway thanks for your kind offer!
could you please elaborate a bit where to connect the scope?