R1,2,3 = 100k
R4,5,6=75r
Me and Cmiu007 built 4 kits of this DAC and the Spdif input never worked. As Cmiu007 already said feed the DAC with SPDIF TTL level thru IC1 isolator and it should work.
Anyway the Spdif input is not a good implementation as the digital source should see a 75ohmm termination and is not like this.
R4,5,6=75r
Me and Cmiu007 built 4 kits of this DAC and the Spdif input never worked. As Cmiu007 already said feed the DAC with SPDIF TTL level thru IC1 isolator and it should work.
Anyway the Spdif input is not a good implementation as the digital source should see a 75ohmm termination and is not like this.
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Skylab
and others... I have never seen that spdif level shifter is made in such resistor values. Digital signal must have 75ohm impedance.
So try to switch resistors... 75 goes to ground... so R1 is 75ohm
R4 is ....ocassionally 100R but i dont know what kind of ic it is. With scope you must get about 5v ttl level on output. If it is too low try smaller R4 resistor value.
and others... I have never seen that spdif level shifter is made in such resistor values. Digital signal must have 75ohm impedance.
So try to switch resistors... 75 goes to ground... so R1 is 75ohm
R4 is ....ocassionally 100R but i dont know what kind of ic it is. With scope you must get about 5v ttl level on output. If it is too low try smaller R4 resistor value.
Hi,
See the two yellow high lighted box on ground and BK which should map to the GND and BCK output pin of the isolator, can I just hotwired them to the spdif input directly (bypassing the isolator) and with S2 set to OFF ?
more like this - s2 off / s1 on
the picture is for i2s/dsd setup
An externally hosted image should be here but it was not working when we last tested it.
no use as the data pins that comes from ic6 have 3v, i presume that because of poor soldering of the chip, the data entry part is faulty - this may be the explanation why some dacs works for 5 minutes and afterwards distorsion apears or in my case one chip burned and the other two works only thru isolator. direct data feeding does not work.
A. direct feed - no lock
B. thru i2s isolator - stable lock (before and after the isolator - i don't remember which is which, but does not matter as they are almost identical)
An externally hosted image should be here but it was not working when we last tested it.
B. thru i2s isolator - stable lock (before and after the isolator - i don't remember which is which, but does not matter as they are almost identical)
An externally hosted image should be here but it was not working when we last tested it.
One thing I don't quite get, the trace coming from the isolator and the direct spdif (IC2) both goes to the same pin under R10, technically if the pin soldering is faulty then both should failed.
When I use the first direct spdif input, I got a solid lock but distorted sound.
Is it possible due to a faulty invertor IC2/3/4? or just a plain bad implementation?
i didn't desoldered them yet, i'm still waiting to replace the burned k2m chip.
it's a little probability to have 4 faulty ic's on 4 boards (atupi's included)
later edit: i'm keeping the working ones as they are for the moment
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