Abraxalito, the summary is mostly right. I started with a full working TDA1543 fed from a DIR9001 that I bought from ebay. As it worked perfectly I decided to mod it by lifting the TDA away from the main board and supplying it with a new, higher voltage regulated supply. (Based upon the ultimate TDA1543 thread). This is when I ran into problems first, I bought 2 more TDAs and tried them in the new setup to no avail. I gave up and put the original TDA back on the board, and it started to work again. I then used the two other TDAs in parallel in a whole new project (again based upon the ultimate TDA1543 thread) fed by the CS8412. I ran into the same problems which I used the shift registers to overcome.
After thinking further about this, the only common layout to the projects was the use of stripboard or similar for the TDAs. There was no shared, continuous ground plane for the digital chips (there was no ground plane at all on or around the TDAs). My amateur guess is that the lack of ground plane was causing some inductance on the I2S lines which was forcing a delay into the ws switching (problem is it did look sharp/square/clean on the scope!). When I added more shift registers i added more digital chips without a ground plane and it made matters worse.
I also tried to make things worse, by adding resistance and increasing the length of the I2S runs. I figured if I could make it worse, I might be able to figure out how to make it better. Think I managed to add a 1m loop of wire onto the data line and 400ohms before I degraded the signal enough to cause problems, but these weren’t delay, just lots of lost bits and corrupted data.
After thinking further about this, the only common layout to the projects was the use of stripboard or similar for the TDAs. There was no shared, continuous ground plane for the digital chips (there was no ground plane at all on or around the TDAs). My amateur guess is that the lack of ground plane was causing some inductance on the I2S lines which was forcing a delay into the ws switching (problem is it did look sharp/square/clean on the scope!). When I added more shift registers i added more digital chips without a ground plane and it made matters worse.
I also tried to make things worse, by adding resistance and increasing the length of the I2S runs. I figured if I could make it worse, I might be able to figure out how to make it better. Think I managed to add a 1m loop of wire onto the data line and 400ohms before I degraded the signal enough to cause problems, but these weren’t delay, just lots of lost bits and corrupted data.
Similar Problem : TDA1543 with AD844 and 3.3V Vref
Hello,
I found this post today after experimenting same problem and having spent several hours building two times the same setup.
I already reported this problem in another post.
Raspberry Pi (picoreplayer) I2S AND USB -> Amanero
RPI or Amanero I2S -> 3K3 x3 -> pin 1,2,3 TDA1543
TDA1543 AOL pin 6 -> pin 2 AD844
TDA1543 Vref pin 7 -> NC
3V3 (TL431) -> pin 3 AD844
pin 5 AD844 -> R IV 330 Ohms to Ground
pin 6 AD844 -> 100K Ohms to Ground
pin 5 or 6 AD844 -> LM1875 NON Inverting input
I can play music with good sound, however, whatever the R IV value, I get HUGE distortion as soon has I move digital volume above 20% from the picoreplayer, don't understand why ???
TDA1543 PSU tried both 5V and 8V25 no change
AD844 PSU +/- 15V
LM1875 PSU +/- 20V
Any idea why I can't move digital volume up to 100 % ?
I have also tried to set passive I/V to make sure, same problem, so only one circuit in play the TDA1543 is the problem...
I have a muse DAC that has 4 TDA1543 in parrallel, put Raspberry Pi I2s and Amanero I2S on it, perfect !
Might be that some TDA1543 are wrong ?
Hello,
I found this post today after experimenting same problem and having spent several hours building two times the same setup.
I already reported this problem in another post.
Raspberry Pi (picoreplayer) I2S AND USB -> Amanero
RPI or Amanero I2S -> 3K3 x3 -> pin 1,2,3 TDA1543
TDA1543 AOL pin 6 -> pin 2 AD844
TDA1543 Vref pin 7 -> NC
3V3 (TL431) -> pin 3 AD844
pin 5 AD844 -> R IV 330 Ohms to Ground
pin 6 AD844 -> 100K Ohms to Ground
pin 5 or 6 AD844 -> LM1875 NON Inverting input
I can play music with good sound, however, whatever the R IV value, I get HUGE distortion as soon has I move digital volume above 20% from the picoreplayer, don't understand why ???
TDA1543 PSU tried both 5V and 8V25 no change
AD844 PSU +/- 15V
LM1875 PSU +/- 20V
Any idea why I can't move digital volume up to 100 % ?
I have also tried to set passive I/V to make sure, same problem, so only one circuit in play the TDA1543 is the problem...
I have a muse DAC that has 4 TDA1543 in parrallel, put Raspberry Pi I2s and Amanero I2S on it, perfect !
Might be that some TDA1543 are wrong ?
Hi Bidule,
I never got to the bottom of my problems, so i don't know if i can be any help. My only suggestion is to have a think about how you have been organising the circuit boards in you setup. As with my last post, my only hunch is the TDA1543 is sensitive to ground plane issues.
Have a look at this thread I've been reading lately might help:
http://www.diyaudio.com/forums/digital-source/31002-ultimate-tda1543-dac-layout.html
Adam.
I never got to the bottom of my problems, so i don't know if i can be any help. My only suggestion is to have a think about how you have been organising the circuit boards in you setup. As with my last post, my only hunch is the TDA1543 is sensitive to ground plane issues.
Have a look at this thread I've been reading lately might help:
http://www.diyaudio.com/forums/digital-source/31002-ultimate-tda1543-dac-layout.html
Adam.
Oh, and the only other thing I can think of is to use a decent large (100uF) decoupling cap after the power regulation for the TDA. I don't think I ever used one in either of my circuits, but from memory the TDA1543 actually switches relativley large currents on its output and this might help?
According to that post, there may be some differrent TDA1543 with "true" I2S and other format that need shift register
http://www.diyaudio.com/forums/digital-source/10838-tda1543a.html
Post #18
What do the experts think ?
http://www.diyaudio.com/forums/digital-source/10838-tda1543a.html
Post #18
What do the experts think ?
Pin 7 Floating
Hello,
I left it floating because I read in different post that it can / should be left floating.
According to my understanding Pin 7 can also be seen as a voltage reference that act as a virtual ground for the next stage.
Taking this into account, one can set an independant virtual ground for the next stage (in my case AD844 pin3) or for other passive I/V.
http://www.diyaudio.com/forums/digital-source/140538-lossless-sd-card-player-9.html Post #86
The TDA1543 chip Vref pin is not connected (very important), an external reference voltage is used instead.
and also here, following your own advice :
http://www.diyaudio.com/forums/digital-source/241865-tda1543-semi-parallel-solution-5.html post #41
Hello,
I left it floating because I read in different post that it can / should be left floating.
According to my understanding Pin 7 can also be seen as a voltage reference that act as a virtual ground for the next stage.
Taking this into account, one can set an independant virtual ground for the next stage (in my case AD844 pin3) or for other passive I/V.
http://www.diyaudio.com/forums/digital-source/140538-lossless-sd-card-player-9.html Post #86
The TDA1543 chip Vref pin is not connected (very important), an external reference voltage is used instead.
and also here, following your own advice :
http://www.diyaudio.com/forums/digital-source/241865-tda1543-semi-parallel-solution-5.html post #41
Post 41 in that thread is by triode_al, not by me.
I'm aware that I've recommended not using the internal pull-up current source within the TDA1543. However its role has to be taken over by some external circuit when this is done. I can't see what's going to take its role in the circuit you've described.
I'm aware that I've recommended not using the internal pull-up current source within the TDA1543. However its role has to be taken over by some external circuit when this is done. I can't see what's going to take its role in the circuit you've described.
Hello adamgillingham
Looks like the problem is a TDA1543 version problem.
In my setup I thought I was using plain vanilla TDA1543, but on the chip it is written TDA1543A.
According to this post : Tweakers' Asylum: Re: Need help with TDA1543A DAC; Finally figured it out! by Elso Kwak
TDA1543A are not I2S input chip !
Looks like the problem is a TDA1543 version problem.
In my setup I thought I was using plain vanilla TDA1543, but on the chip it is written TDA1543A.
According to this post : Tweakers' Asylum: Re: Need help with TDA1543A DAC; Finally figured it out! by Elso Kwak
TDA1543A are not I2S input chip !
Right - I got that far from your description. And without the pull-up CS, the 1543 is only going to sink current into the AD844 pin2. You have a current conveyor so the sink current will be conveyed to the 330R resistor to GND. The voltage across your 330R therefore isn't going to be centred around 0V (it'll have a positive offset of a few hundred mV) so ISTM you'll need a cap in the signal path somewhere which I didn't see mentioned.
Hello abraxalito,
You are right, I ommited to metion it !
I use a LM1875 in current drive mode with a 2.2 µF Jenzen Input CAP.
I have measured a DC Offset of around 900 mv.
I have als tried to null it (not mentioned either) from AD844 pin 1 and 8 conneted to a 22K pot that has its central point to +15V as per AD884's datasheet
However for another unclear reason it didn't work as expected !
You are right, I ommited to metion it !
I use a LM1875 in current drive mode with a 2.2 µF Jenzen Input CAP.
I have measured a DC Offset of around 900 mv.
I have als tried to null it (not mentioned either) from AD844 pin 1 and 8 conneted to a 22K pot that has its central point to +15V as per AD884's datasheet
However for another unclear reason it didn't work as expected !
If it's marked as TDA1543A, then it needs a different format. Do a google search, I did find somone hosting a copy of the datasheet when I looked last night. (on diyhifi.org)
You may be able to fix the format using shift registers, or just buy some non-A chips.
As far as I'm aware all my chips were non-A, they just suffered issues with bad layout.
It's not great news, but at least you know what's up with your setup now.
Adam.
You may be able to fix the format using shift registers, or just buy some non-A chips.
As far as I'm aware all my chips were non-A, they just suffered issues with bad layout.
It's not great news, but at least you know what's up with your setup now.
Adam.
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