Twisted Pear S/PDIF WM8804 Transceiver Module on TDA1541A problem

Hi to all,

i would use the WM8804 to convert the S/PDIF to I2S (16bit). The I2S should feed my TDA1541A NOS DAC.

Unfortunately i have no sound output :( , independent if i set the I2S to 16 or 24 bit (AIFCONF0 1 or 0).

Malka07 use the same DAC pcb´s from me and have also no luck.

The connections are as follows:

LRCLK to TDA Pin1
BCK to TDA Pin2/4
Data to TDA Pin3.

Can someone help?


With my Teradak X2 USB to I2S converter, everything works fine!

Best regards,
Oliver
 
Last edited:

vanwykca

Member
2009-01-14 3:57 pm
Hi Oliver,

I've checked my setup(TP 8804 into TDA1541a NOS) and had a look at the TDA data sheet and it looks like pin27(OB/TWC) on the TDA has to be pulled high(connected to pin28/VDD/+5v) to allow it to accept multiplexed two's complement/I2S input. Might be worth checking in your setup.

Regards
Cornelius
 

io

Member
2006-05-01 10:27 am
Hungary
I2S 16bit
 

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io

Member
2006-05-01 10:27 am
Hungary
hi

I am using WM8805, WM8742, but I think this should be good to 8804

WM8804--TDA1541
16bit I2S hardware

1--H
2--L
3--L
4--L
5--Unlock(3v3-10k-led)
6--
7--3V3+
8--AGND
9--
10-Xtal
11-Xtal
12-Data out
13-
14-Bclk-out
15-LRck-out
16-
17-
18-DGND
19-3V3+
20-Spdif-IN
 
Can you please confirm there is at least LRCK signal? (if you have oscilloscope, that is). If you don't have oscilloscope, simply measure DC from LRCK to GND and report back. Measure DC with and without music playing.

Also, what are the status LEDs saying? All off?

Last thing which comes to mind: is the DAC powered from the same supply? If not, you might need to also connect the GNDs of the 2 boards?
 

Malka07

Member
2009-03-16 11:23 am
Can you please confirm there is at least LRCK signal? (if you have oscilloscope, that is). If you don't have oscilloscope, simply measure DC from LRCK to GND and report back. Measure DC with and without music playing.

Also, what are the status LEDs saying? All off?

Last thing which comes to mind: is the DAC powered from the same supply? If not, you might need to also connect the GNDs of the 2 boards?

Hi and thanks for your help.

I have the same dac as Oliver(Dvb-projekt) and am also having the same problem. I dont have an oscilloscope, but i measured dc from LRCK to GND with and without music playing and both times i got 1.64v.

All LEDs are green when a coax cable in connected to the dac regardless of if music is playing or not. If the coax is disconnected then all lights are red except non audio which remains green.

I have Gnd on my Twisted Pair board connected to Gnd on the dac board.

Pictures of the dac can be seen in this thread along with Board layouts etc...maybe that will help too.

http://www.diyaudio.com/forums/group-buys/167414-reference-tda1541a-dac-i2s-bus-architecture.html

Page 1 shows the board layouts....and page 31 onwards, are pics of my dac with the problems im having.

Thank you all, for your kind help...i really would like to get to the bottom of this, and im sure Oliver would too.

Alon
 
Alon,

i´ve got an advice from John (ecdesigns) to our problem.


Hi Oliver,

It seems highly unlikely that a batch is not working.

WM8804 typical supply voltage equals 3.3V. The I2S attenuators you are
using are designed for 5V TTL levels only. This could also explain why
there is no sound with this particular module.

You could temporarily remove / bypass the I2S attenuators to see if
this is causing the problems. This could be done easiest by bypassing
the series resistors for DATA, BCK and WS.

I could test it this evening. Perhaps your are able to test this earlier.

:cheers:
 
I´ve looked deeper on the three modules (TP WM8804, Y1 PCM2707 & X2 TE7022). :magnify:
All three IC´s runs with 3.3V, so that´s not the difference.

The X2 is the only one, witch have a BUS Buffer (74HC125) between the converter IC and the I2S output.

On the Twisted Pear and the AMB Y1 pcb lacks this buffer.

I will try to insert such a buffer IC between the output of my TP WM8804 and the I2S input of the DAC module in the next days and report the result.
 
I have made some quick measurements with my oscilloscope:

Left: Teralink X2 BCK - Right: TP WM8804 BCK

[IMGDEAD]http://img695.imageshack.us/img695/976/sam0202i.jpg[/IMGDEAD] [IMGDEAD]http://img593.imageshack.us/img593/8408/sam0205u.jpg[/IMGDEAD]

Left: Teralink X2 LRCK - Right: TP WM8804 LRCK

[IMGDEAD]http://img508.imageshack.us/img508/4939/sam0203.jpg[/IMGDEAD] [IMGDEAD]http://img11.imageshack.us/img11/4783/sam02060.jpg[/IMGDEAD]


Left: Teralink X2 Data - Right: TP WM8804 Data

[IMGDEAD]http://img227.imageshack.us/img227/139/sam0204.jpg[/IMGDEAD] [IMGDEAD]http://img19.imageshack.us/img19/5224/sam0207l.jpg[/IMGDEAD]


Independent from the signal quality, any thoughts?
It seems that the Buffer in the X2 made a bit more output voltage.