Oh, that's what they are for. I kind of thought that, but wasn't sure. I ordered the parts, so when they get here, I should start assembly soon.
Thanks.
Thanks.
Prune
I can't find anyone that stocks these MUR4100 recitifier diodes. Digikey has a lead time of until june, newark has a lead time of 85 days. You know of any other suppliers that will sell for reasonable amounts or a good substitute to use? I'm sure 1N4003's will work fine, but their currect rating is 1A, not 4, and they are not fast recovery.
Thanks.
I can't find anyone that stocks these MUR4100 recitifier diodes. Digikey has a lead time of until june, newark has a lead time of 85 days. You know of any other suppliers that will sell for reasonable amounts or a good substitute to use? I'm sure 1N4003's will work fine, but their currect rating is 1A, not 4, and they are not fast recovery.
Thanks.
Actually, I found a supplier. Arrow Electronics had them. Now all I have to do is wait for everything to come.
Thanks.
Thanks.
The DAC is finally assembled except for the pulse transformer. That should arrive Monday. Soldering really wasn't too difficult, just tedious. Once it is operating, I'll start assembling the power supply. I really hope this works, because rework will not be very easy.
Prune,
Have you built yours yet? Have you got your PCB made by Olimex? I imagine the perfect test would be the S/PDIF output on my sound blaster audigy or the coax output on my dvd player? I cant really try anything else until the pulse transformers arrive to build the coax output circuits on the other devices I have.
Thanks.
Prune,
Have you built yours yet? Have you got your PCB made by Olimex? I imagine the perfect test would be the S/PDIF output on my sound blaster audigy or the coax output on my dvd player? I cant really try anything else until the pulse transformers arrive to build the coax output circuits on the other devices I have.
Thanks.
I built mine a long time ago.
Warning!
A lot of Creative cards have digital output with voltage way beyond spec, in some cases as much as 9V! Test with the DVD player's output; for the sound card you may need a TTL to S/PDIF level converter.
Warning!
A lot of Creative cards have digital output with voltage way beyond spec, in some cases as much as 9V! Test with the DVD player's output; for the sound card you may need a TTL to S/PDIF level converter.
Well,
I assemble the power supply and get it working. I received the pulse transformer today. Now, when I go to test, it does not work. U1, which is the 5V regulator, only putputs 900mV according to my meter, U5 outputs 3.9V or around there. Have I fried U1 and maybe U5 with too much heat?
I assemble the power supply and get it working. I received the pulse transformer today. Now, when I go to test, it does not work. U1, which is the 5V regulator, only putputs 900mV according to my meter, U5 outputs 3.9V or around there. Have I fried U1 and maybe U5 with too much heat?
Ok, I replaced the regulator and I get 5V out, but all I hear is static. I power the DAC, I hear this buzzing at first (probobly the voltage monitor), then I hear static. It gets louder and louder it seems, with a popping sound too.
Anyone know what could be wrong? I don't have a scope so I can't observe any waveforms.
Anyone know what could be wrong? I don't have a scope so I can't observe any waveforms.
I've also noticed the CS8420 gets HOT after being on for a while. So could the CS8420 section be the problem?
After furthur inspection, U5 seems to be bad, outputting 2.6V. I used my last replacement on U1. I'm thinking heat damaged these regulators, because they are so small and easily killed by the heat. I'll order some more and hope this will solve the problem. Is the audio output all static and noise a symptom to a problem of a dead CS43122 or is it just underpowered?
Your soldering iron may be too hot, or you are applying it for too long. To avoid this, I highly recommend this cheap and simple DIY hot air pencil:
http://www.usbmicro.com/odn/documents/46.html
Or at least use an iron with temperature control, or a low wattage one.
Do not use a voltmeter to test connections. It puts out voltage when in resistance and diode modes, which at the wrong pin may fry something.
Ground yourself and keep parts away from static. Static really is an issue with these parts.
But most likely your problem is soldering. Often it's very hard to see small solder bridges and cold joints. Burnt flux is not a good insulator. You can use a sharp tipped pick or tweezers to scrape between small pitch joints to make sure there's not a small bridge or lodged solder particle.
Yes, the reciever and DAC chips get hot, but should not be too hot. The clock and CS43122 analog regulators should only be warm; the digital regulators (the ones close to each other) do get quite hot.
When you test it, have it connected to the DVD player's coaxial output with something playing (as I said previously, some sound cards output too much voltage). Sometimes with no input the thing produces noise.
BTW if you can post a high resolution scan (PNG format, or if you use JPEG use the maximum quality compression) of both sides we may notice something you didn't.
http://www.usbmicro.com/odn/documents/46.html
Or at least use an iron with temperature control, or a low wattage one.
Do not use a voltmeter to test connections. It puts out voltage when in resistance and diode modes, which at the wrong pin may fry something.
Ground yourself and keep parts away from static. Static really is an issue with these parts.
But most likely your problem is soldering. Often it's very hard to see small solder bridges and cold joints. Burnt flux is not a good insulator. You can use a sharp tipped pick or tweezers to scrape between small pitch joints to make sure there's not a small bridge or lodged solder particle.
Yes, the reciever and DAC chips get hot, but should not be too hot. The clock and CS43122 analog regulators should only be warm; the digital regulators (the ones close to each other) do get quite hot.
When you test it, have it connected to the DVD player's coaxial output with something playing (as I said previously, some sound cards output too much voltage). Sometimes with no input the thing produces noise.
BTW if you can post a high resolution scan (PNG format, or if you use JPEG use the maximum quality compression) of both sides we may notice something you didn't.
I recommend examining all your soldering work under a microscope or powerful magnifying glass, and using a bright light. My philosophy of soldering is that the operation should take at most a few seconds for SMT parts, and the result must be not only correct, but also aesthetically appealing. Anything ugly or embarrasing is likely to not work properly.
jwb,
Almost all of the soldering done is astheticly appealing, I really think the issue is heat.
Prune,
From what you said, I think the CS8420 and everything around there is fine. It doesn't get too hot, but it gets hot. I have looked at it and never really saw anything out of the ordinary, though I could have shorted it, because I never aligned it as best I could, but I spend a lot of time using heat on it, and that could have fried it, because it only had 2.6V on it's output.
I have one of those desoldering irons, just no pump, which I will get soon. I'll be EXTRA carefull soldering this regulator in. Also, I'm concerned about the noise it makes. I unsoldered the defective regulator (U5), and still made noise that it did. The buzzing at first (sounds more like a bunch of pulses, I'm not really sure what causes that, anyone else know?), then static, which gets increasingly louder, then you hear intermitant poping sounds. Is this the noise you hear with no input?
Also, the transformers I received today seem very flimsy. The ferrite core seems very loose and move easily. I received 5 and all are like that, but I soldered one in anyway alighing it was difficult, because I held the core with tweezers, and the bobbin part moved around slightly. Is this normal or did I get defective transformers? I got them from tweakaudio.net. Any movement of the core will change the properties of the windings, but will it affect the S/PDIF transmission that much?
Thanks.
Almost all of the soldering done is astheticly appealing, I really think the issue is heat.
Prune,
From what you said, I think the CS8420 and everything around there is fine. It doesn't get too hot, but it gets hot. I have looked at it and never really saw anything out of the ordinary, though I could have shorted it, because I never aligned it as best I could, but I spend a lot of time using heat on it, and that could have fried it, because it only had 2.6V on it's output.
I have one of those desoldering irons, just no pump, which I will get soon. I'll be EXTRA carefull soldering this regulator in. Also, I'm concerned about the noise it makes. I unsoldered the defective regulator (U5), and still made noise that it did. The buzzing at first (sounds more like a bunch of pulses, I'm not really sure what causes that, anyone else know?), then static, which gets increasingly louder, then you hear intermitant poping sounds. Is this the noise you hear with no input?
Also, the transformers I received today seem very flimsy. The ferrite core seems very loose and move easily. I received 5 and all are like that, but I soldered one in anyway alighing it was difficult, because I held the core with tweezers, and the bobbin part moved around slightly. Is this normal or did I get defective transformers? I got them from tweakaudio.net. Any movement of the core will change the properties of the windings, but will it affect the S/PDIF transmission that much?
Thanks.
With the hot air pencil, make sure you stuff enough fine steel wool to get good heat transfer. You don't need fast airflow. If you still can't get it hot enough to melt the solder, after the part has warmed up, briefly touch the lead you are soldering, that should do it.
Make sure you didn't put the input transformers on backwards. I think the higher resistance winding goes to the reciever, the lower to input.
BTW I grounded the transformer shield to digital ground.
Make sure you didn't put the input transformers on backwards. I think the higher resistance winding goes to the reciever, the lower to input.
BTW I grounded the transformer shield to digital ground.
Yes, the side with the red dot is the side that connects to the BNC connector. Now I just have to wait for the replacement regulator to come...
Ok, regulators came today, it was a waste of money. I put the new one in and it outputs 2.4V. I then lifted pins 7 and 8 of the CS43122 and got 4.4V out of the regulator, which seems closer to normal, but the digital supply is still connected via the resistor array. Have I fried the CS43122 due to heat as well? I have a feeling I did. I did use solder wick on it about 3 times, which heated it up quite well, though I did let it cool each time. I really don't understand how heat may cause a short, but I guess it could. Before I order another $14.00 CS43122, I'd like your opinion on it. When U5 connected to the CS43122, it's voltage output is 2.4V. When I lift pins 7 and 8 of the CS43122, it increases to 4.4V. Any ideas here on what could be wrong?
Thanks.
Thanks.
Different materials expand differently when heated. The tiniest crack can be enough to damage the microscopic circuit. Plus, I thought that the output is supposed to be 5V, not 4.4V. That indicates there's a problem besides the CS43122. Check that C13 and C14 are not shorted. If that's not the problem, disconnect everything else connected to the output one by one, and see when it returns to the correct 5V. Most likely it's a soldering problem, less likely something is fried. Hopefully it's not the DAC chip.
You should have soldered the two big chips last, after having verified that everything else was working properly.
You should have soldered the two big chips last, after having verified that everything else was working properly.
Ok, stupid problem. Pin 4 of U5 was not grounded. Silly me. Now I get 5V like I should, from all 3 5V regulators and 5.5V from the adjustable regulator. But, now I get no sound what so ever. No noise, just a pop when I plug in the power supply, but otherwise silence. I think I ruined something when I lifted the two pins. Possibly the CS43122 was ok before, now it's dead. This really ****es me off because removing the SOIC from the PCB will not be easy when I lost be solder pick. The output is connected to a PC speaker amplifier, with the cap in series to block the DC level. This will be for testing. Before I got the pulsing noise, then the static, then the pops inside the static, but now nothing. When I touch the meter probe to the input of the line driver, I get a loud pulsing noise much like the pulsing noise before when it first turned on, except this happens whenever I touch the meter lead to the input. This project has been a major hair-pulling experience for me 🙂
Prune and jwb, I really do appreciate your help. Do you guys have any idea as to what could be wrong now? Fried CS43122?
Prune and jwb, I really do appreciate your help. Do you guys have any idea as to what could be wrong now? Fried CS43122?
First make sure the line driver is working right. Disconnect the 300 ohm resistors that go from the CS43122 to the line driver input and try sending line level analog music to each input, making sure it comes out fine at the outputs.
Is the voltage monitor turning the chips on? Look at the schematic and check voltages. How much current is each section drawing from the power supply (hook the meter in series to measure current)?
Is the voltage monitor turning the chips on? Look at the schematic and check voltages. How much current is each section drawing from the power supply (hook the meter in series to measure current)?
Ok, I looked at the output of the voltage monitor, and form what it looked like to me, it constantly stayed at 3.17, even when I first applied power to it. I inserted it according to the silkscreen and a double check with the datasheet for pinout and the pinout was correct. The section with U5 and U6 draws 76mA with no coax input connected. U1 which drives the clock and the analog section of the CS8420 draws 21mA. The analog supply for the CS43122 and the positive side of the line driver draws 34.3mA. I also connected an audio source to the line drivers inputs, which was a pocket digital radio driven by a AAA battery and I got sound on all four inputs.
So, looks to me that the ICs, for some reason, are not being reset upon power up. The voltage monitor is being driven by 4.9V according to my meter. I have a feeling if i replace the voltage monitor, it still wont work... Anyone know what else could be wrong?
So, looks to me that the ICs, for some reason, are not being reset upon power up. The voltage monitor is being driven by 4.9V according to my meter. I have a feeling if i replace the voltage monitor, it still wont work... Anyone know what else could be wrong?
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