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Old 23rd January 2013, 04:27 PM   #1631
JLOP is offline JLOP  France
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the Alsa mixer may be good software, but its ergonomics is definetely 19th century. It would be good that someone competent (not me (:-() rewrite it in an appropriate way
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Old 23rd January 2013, 11:13 PM   #1632
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Originally Posted by JLOP View Post
the Alsa mixer may be good software, but its ergonomics is definetely 19th century. It would be good that someone competent (not me (:-() rewrite it in an appropriate way
In your mpd.conf, alsa section just write theese lines:

mixer_type "hardware"
mixer_device "hw:0"
mixer_control "Luckit Clock Selector"
mixer_index "1"

You will be able to adjust volume via your mpd client: gmpc, mpdroid, mpad...

Last edited by Sagittarius; 23rd January 2013 at 11:30 PM.
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Old 25th January 2013, 07:31 PM   #1633
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Default Please help digital noob

Hello,

I plan to make a nice streaming client with the WaveIO board. So I've ordered and received such a board. As I'm new on digital diy-audio I'd like to take things step by step.

First thing: hooked the WaveIO up to my Linux laptop via the USB-cable. The plugged the isolated s/pdif into a dac. And yes! music!

Time for the next step (with which a miserably failed): connect a TDA1543 DAC to the isolated I2S. Whatever I do, I get no sound at all.

So what did I do (see attachment)?
First the analogue part:
I'd like to keep things simple for a starter. I've a passive I/V stage (270 ohm resistor to ground. the resistor to set Vref is a 2K trim pot to ground).
I stacked 8 TDA1543's on top of each other and gave each one a separate decoupling capacitor (100nF multilayer) and a seperate lead to the 8.4V power supply. I think this part is OK, or at least good enough to get some sound.

Then the digital part (I suppose something is wrong here):
I created a 3.3V power supply which I connected to J5 of the WaveIO board. The positive lead to the pin marked V+, the ground lead to the pin next to it (marked isol. gnd).

Then for each of the 3 I2S lines I've made a twisted wire of 2 leads (about 3 cm long). Lets take the data lead as example for what I did for each of the twisted wires. One of the leads is connected to the WaveIO pin marked DT, the other side to the data pin of the TDA1543. The other lead is connected to WaveIO pin next to the DT pin (marked isol. gnd) and to the DAC chip gnd pin.

I use the ground pin of the DAC as ground star for the 3.3V supply and the 8.4V supply.
I created an analogue ground star at the output connector. Digital and analogue ground meet at the power supply ground feeding the 3.3 and 8.4 regulators.

What am I doing wrong as there is absolutely no sound. This is what I checked:
- all connections checked and double checked
- power supply voltages
- DC output voltage of DAC (about 1V and a bit)
- DC voltage on I2S lines (there is some)

Please help, how can I find the mistake?
Any help appreciated, MArco
Attached Files
File Type: pdf New Document 4.pdf (309.3 KB, 99 views)
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Old 25th January 2013, 08:23 PM   #1634
Ben Mah is offline Ben Mah  Canada
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Quote:
Originally Posted by deduikertjes View Post
Hello,



Time for the next step (with which a miserably failed): connect a TDA1543 DAC to the isolated I2S. Whatever I do, I get no sound at all.

So what did I do (see attachment)?

I stacked 8 TDA1543's on top of each other and gave each one a separate decoupling capacitor (100nF multilayer) and a seperate lead to the 8.4V power supply. I think this part is OK, or at least good enough to get some sound.
I think that the issue is the 8 dac chips. The isolator is not able to drive that many chips. A buffer between the isolator and the dac chips is required. A 74HC125 may be used to to buffer the I2S signals. Check out Doede Douma's DDDAC 1543 circuit which shows a 74HC125 in the I2S path.
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Old 25th January 2013, 08:47 PM   #1635
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Quote:
Originally Posted by Ben Mah View Post
I think that the issue is the 8 dac chips. The isolator is not able to drive that many chips. A buffer between the isolator and the dac chips is required. A 74HC125 may be used to to buffer the I2S signals. Check out Doede Douma's DDDAC 1543 circuit which shows a 74HC125 in the I2S path.
Thank you! Never thought of that. Can you please elaborate a bit?
Why is the chip not capable of driving that many chips? Does the PS to the isolator make any difference? How many chips should it be able to drive?

Thanks, MArco
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Old 25th January 2013, 10:42 PM   #1636
Ben Mah is offline Ben Mah  Canada
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Quote:
Originally Posted by deduikertjes View Post
Thank you! Never thought of that. Can you please elaborate a bit?
Why is the chip not capable of driving that many chips? Does the PS to the isolator make any difference? How many chips should it be able to drive?

Thanks, MArco
The isolator chip has a maximum output level. If the output is divided many times, it is logical (pun intended) that at some point the logic levels become too low for the dac chips to recognize. I don't have any experience with the 1543 so I do not know what is the maximum number of chips.

Increasing the isolator supply to 5 volts will increase the output of the isolator. You should confirm with the data sheet or Lucian that 5 volts is feasible. However, will the increase be enough to drive the eight dac chips?

You can also try using only one dac chip to see if it works, to confirm that it is an issue with the logic levels.
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Old 26th January 2013, 09:58 AM   #1637
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Quote:
Originally Posted by Ben Mah View Post
Increasing the isolator supply to 5 volts will increase the output of the isolator. You should confirm with the data sheet or Lucian that 5 volts is feasible. However, will the increase be enough to drive the eight dac chips?

You can also try using only one dac chip to see if it works, to confirm that it is an issue with the logic levels.
I've tried with 5v (datasheet of the isolator specifies a max of 7v). No sound ...

Trying onlyone dac chip is very difficult. I can't easily take one out of the tower.
Or would it be enough to remove the power supply to 7 of the 8 dac chips?
Is there a way to measure if levels to the dac chips are ok? I don't have a scope ...

Thanks, marco
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Old 26th January 2013, 12:37 PM   #1638
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Quote:
Originally Posted by deduikertjes View Post
. . . would it be enough to remove the power supply to 7 of the 8 dac chips?
With only eight DAC chips, I doubt fanout (max no of chips a device can drive) is your problem though it might be. Fetch the schematics from DD's site and use them to check your build. (They'll also show you where to add a buffer chip between the WaveIO and the DAC chips.) I'd start by using USB power to drive the board (set the jumper!) and making sure you have:

WaveIO DT (pin 3) > TDA1543 Data (pin 3)
WaveIO LR (pin 5) > TDA1543 WS (pin 2)
WaveIO BC (pin 7) > TDA1543 BCK (pin 1)

and good ground connections. Pin 1 of the isolator chip is marked on the PCB.

If you've check all that but still get no sound, fanout might just be your problem. If it's easy to remove the power to the DAC chips, consider removing it from, say, six of the eight devices. The 270R resistor shown on your diagram is not ideal for I/V for two chips but should be fine for testing.

Good luck.
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Old 26th January 2013, 07:07 PM   #1639
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Quote:
Originally Posted by Ryelands View Post
I'd start by using USB power to drive the board (set the jumper!) and making sure you have:

WaveIO DT (pin 3) > TDA1543 Data (pin 3)
WaveIO LR (pin 5) > TDA1543 WS (pin 2)
WaveIO BC (pin 7) > TDA1543 BCK (pin 1)

and good ground connections. Pin 1 of the isolator chip is marked on the PCB.

If you've check all that but still get no sound, fanout might just be your problem. If it's easy to remove the power to the DAC chips, consider removing it from, say, six of the eight devices. The 270R resistor shown on your diagram is not ideal for I/V for two chips but should be fine for testing.
Thank you for your suggestions. I'm running the board from USB power.
Checked all connections for the third time.
Cut power lines to 7 of the 8 dac chips. Still no sound at all ...

I've not a clue. Are there any basic checks that I can do?

MArco
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Old 26th January 2013, 08:19 PM   #1640
Ben Mah is offline Ben Mah  Canada
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Quote:
Originally Posted by deduikertjes View Post
Thank you for your suggestions. I'm running the board from USB power.
Checked all connections for the third time.
Cut power lines to 7 of the 8 dac chips. Still no sound at all ...

I've not a clue. Are there any basic checks that I can do?

MArco
Are you still using the isolated out and is the power still applied to the output side of the isolator?

When you send music to the WaveIO, is there voltage on the data output? With no music there should be no voltage and with music there should be voltage.

If you get output from the LR, BC, and DT and the wiring is correct to the dac chip (check for shorts to ground - check that there is voltage at the dac inputs), then check your dac. Check for correct power supply voltage at the chip, check for loose wires, bad solder connections, and that all grounds are connected.

Good luck.
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