"Reference" TDA1541A DAC with I2S-BUS architecture

[dvb projekt]

I think a few detailed photos of your setup could help!

 

[studiostevus]

I hope it will... Sorry for the mess, i have been trying quite some things to find the problem.

How do i check whether spdif signal is locked? What is the expected output voltage at tda output?

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

Thanks for your help...

 

[Malka07]

Hi Studiostevus,

On your dac pic, I see no signal return/gnd connected at audio out...could this be the reason for no sound?

Alon

 

[studiostevus]

I have connected the grounds via my dmm cables. Not perfect, and i will end up with star ground once i yet everything running.
But even with imperfect gnd, there should be some sound...

 

[dvb projekt]

Did you have the V2.3 revision of the DAC module?

 

[studiostevus]

Yep

 

[dvb projekt]

As far as i could see it on the pictures, there is no failure in the connection.
Are the 3 voltages (+5V, -5V, -15V) direct at the TDA1541A correct?

 

[studiostevus]

Ok, so that should not be the problem.

I read somewhere that i should read 3-4V dc at the output of the tda. Can somebody confirm that, because I dont get that?

Also if i put in a test resistor to ground, i would expected at least voltages that vary with the music. I dont get that.

I do get i2s signal that varies with the music though (on/off), so my working hypothesis is that the i2s going to dac is ok.

 

[dvb projekt]

Ok, so that should not be the problem.

I read somewhere that i should read 3-4V dc at the output of the tda. Can somebody confirm that, because I dont get that?

Also if i put in a test resistor to ground, i would expected at least voltages that vary with the music. I dont get that.

I do get i2s signal that varies with the music though (on/off), so my working hypothesis is that the i2s going to dac is ok.

Normally you should measure some small AC (mV) at the output with connected I/V resistor.

 

[dvb projekt]

The I2S switch module (e.g. USB & SPDIF) is ready

An externally hosted image should be here but it was not working when we last tested it.

- separate relays for each I2S signal to get the maximum HF-Isolation
- based on the Takamisawa NA-5WK relay, witch has minimal HF-Insertion loss
- 2mm pcb
- Immersion Gold
- green soldermask on both side
- 35µm copper weight
- Board size 45mm x 35mm

The price for it is $8 (naked module as on the right side on the photo)

Worldwide shipping: $ 4
paypal fee: 3,9%

​

 

[neda]

Hi Oliver,

I've been reading over this thread the past couple of days, and my head is spinning to say the least. But very interesting.
I've assembled amps and modified preamps and cd players in the past, but have no experience with dacs.
I see you, and some other members are using 2 DAC module boards in your setups. Can you please tell me what the advantage of this configuration is?

Thank You,
Ned

 

[dvb projekt]

Hi Ned,

with 2 DAC's linearity errors are reduced and signal to noise ratio improves.


Best,
Oliver

 

[neda]

Does the 2 dac module board setup require 2 tda1541a shunt regulator module boards also?

 

[dvb projekt]

No, you could use one TDA1541A shunt module also for a double DAC module config.

 

[neda]

Oliver,

I'm planning on building this dac with S/PDIF input from my cd transport only.
No USB. Using a T/P WM8804 receiver. So, I'm assuming I will need the following items, correct me if I'm wrong.

2x Power supply modules
1x TDA1541a shunt reg. module
1x Shunt reg module for 5v line
2x TDA1541a Dac modules (might as well do it right)
1x Tube-I-Zater v2.0 module
2x NL17SZ02 adapter PCB
1x Ultra high speed buffer module

I don't need the I2S switch module since i'm not using usb, correct?

Let me know if I'm forgetting something. I would like e to get it all in one order.

Best regards,
Ned

 

[dvb projekt]

Oliver,

I'm planning on building this dac with S/PDIF input from my cd transport only.
No USB. Using a T/P WM8804 receiver. So, I'm assuming I will need the following items, correct me if I'm wrong.

2x Power supply modules
1x TDA1541a shunt reg. module
1x Shunt reg module for 5v line
2x TDA1541a Dac modules (might as well do it right)
1x Tube-I-Zater v2.0 module
2x NL17SZ02 adapter PCB
1x Ultra high speed buffer module

I don't need the I2S switch module since i'm not using usb, correct?



Let me know if I'm forgetting something. I would like e to get it all in one order.

Best regards,
Ned

Hi Ned,

not a must, but with the Salas HV-Shunt module is sounds much better

 

[neda]

Yes, I want that also. Give me the works.

Please add everything up including all fees, and I will paypal you the amount
tonight after work.

 

[dvb projekt]

The invoice for the whole project is sent

 

[noizas]

Ok, so that should not be the problem.

I read somewhere that i should read 3-4V dc at the output of the tda. Can somebody confirm that, because I dont get that?

Also if i put in a test resistor to ground, i would expected at least voltages that vary with the music. I dont get that.

I do get i2s signal that varies with the music though (on/off), so my working hypothesis is that the i2s going to dac is ok.

hi,

if I2S timing is ok and input data values are zero, one TDA1541 output has -2mA current output offset.
So with connected I/U resistor (let say 25 Ohm) between output and analog ground you should have about 50mV negative DC offset on output in silence.
If two parallel outputs are connected, those will sink 4mA from the source (AGND) via I/U resistor correspondingly.

 

[studiostevus]

This is what I measured, with a 75.3Ohm resistor.

Result is -213mVdc, so -2.8mA.

This is too high, but not sure it would be outside parameters. Also it doesnt change with the music. So it could be
1) something with the tda or the dac-setup
2) something with the spdif supply from doede douma's board. I have measured the i2s voltages. I measure

No SPDIF signal:
bck = 2.05 vdc
data = 0.1 vdc
fs = 2.24 vdc

SPDIF Signal applied:
bck = 2.05 vdc
data = 1.2-1.6 vdc varies
fs = 1.9 - 2.4 vdc varies

does that seem ok?