Invert WS?????
For the Universal Shifter (noted earlier) I use -- which works perfectly -- WS is brought into the TDA1545A unchanged.
However, DATA is inverted (??) in the final step in which an inverted BCK is used as CLK signal for lone 74HC74 to which DATA must pass thru before the DAC.
I'm away from my workbench for a while so no way to test this for some time ...IAC, are you suggesting simply invert WS using, say, 74HC04? The Black Crow does not appear to do this (see post above) or look at this image...
For the Universal Shifter (noted earlier) I use -- which works perfectly -- WS is brought into the TDA1545A unchanged.
However, DATA is inverted (??) in the final step in which an inverted BCK is used as CLK signal for lone 74HC74 to which DATA must pass thru before the DAC.
No - if that was the problem (180 degree phase shift of WS) the only result would be the channels got swapped (and one was a sample late). So no, there's more to it than that.
Three 74HC174's + pwr
Hmm....well that Black Crow device is supposed to work with three (3) 74HC174s -- the model in the image has supposedly been marketed and sold by diyparadise.com for several years now.
So I may have some "short" or PSU issue, tho' my o'scope traces look decent.
I still don't understand that whine/buzz that disappears once WS and/or BCK are disconnected. This is with DATA connected (but no active stream -- i.e., player in STOP or PAUSE)???
BTW: for the Black Crow, the single 74HC125 on the far right is just a buffer, not really needed (e.g., you can also use small value R's here as many do for the three-line DAC feed).
Hmm....well that Black Crow device is supposed to work with three (3) 74HC174s -- the model in the image has supposedly been marketed and sold by diyparadise.com for several years now.
So I may have some "short" or PSU issue, tho' my o'scope traces look decent.
I still don't understand that whine/buzz that disappears once WS and/or BCK are disconnected. This is with DATA connected (but no active stream -- i.e., player in STOP or PAUSE)???
BTW: for the Black Crow, the single 74HC125 on the far right is just a buffer, not really needed (e.g., you can also use small value R's here as many do for the three-line DAC feed).
Still haven't solved it!
Away from my bench ... so just theorizing here in public transit:
The working Universal Shifter brings BCK and WS into TDA1545A unchanged...
However, I have three 47-ohm damping R's on the 3-74HC174 converter (i.e., between converter and DAC, for BCK, WS and DATA) while the Universal Shifter has no damping R's.
Away from my bench ... so just theorizing here in public transit:
The working Universal Shifter brings BCK and WS into TDA1545A unchanged...
However, I have three 47-ohm damping R's on the 3-74HC174 converter (i.e., between converter and DAC, for BCK, WS and DATA) while the Universal Shifter has no damping R's.
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