Hi all!
I'm really a dumb on digital tech, but I'm also curios and I wish to know if somebody can explain me how it works the output part of the Pass' DAC, whose schematic is on the d1-srv-man.pdf file on Passlabs site.
Well, I'm concerning on the U12 and U17 PCM chips.
It seems that the input data are the same, but the output signals follows different path, in fact they are worked out as hey are opposite in phase, obtaining a balanced output.
Ok, where is the trick? In some way the logical port before the PCMs did the work? how?
Thank you in advance,
I'm really a dumb on digital tech, but I'm also curios and I wish to know if somebody can explain me how it works the output part of the Pass' DAC, whose schematic is on the d1-srv-man.pdf file on Passlabs site.
Well, I'm concerning on the U12 and U17 PCM chips.
It seems that the input data are the same, but the output signals follows different path, in fact they are worked out as hey are opposite in phase, obtaining a balanced output.
Ok, where is the trick? In some way the logical port before the PCMs did the work? how?
Thank you in advance,
Faber said:Do you mean that transform 1 -> 0 and 0 -> 1 it's all the work to do to have an exactly inverted waveform?
thanks
That 1 and 0 are a square wave form that is inverted "logically" speaking . I am confidential with Philips I2S signals where the DATA is inverted just to have an inverted signal(or waveform) at the audio output.
74HC86 are exclusive OR gates. Data at U9-A is XORed with 0, so it's pass through (1 -> 1 and 0 ->0). Data at U9-B is XORed with 1, so it's inverted (1 -> 0 and 0 ->1). If you use PCM-1704, these inverting logic is built-in. The shcematics only showed left channel. The right channel duplicates the left but uses DOR data.
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