W skrócie: SPDIF - pasmo powinno być do 30 MHz. Lampki nie HF lub VHF tak, jak napisał karbidoczaszka nie zadziałają dobrze.
Cytat z ŁF - artykuł na temat transportu.
The SP/DIF
signal is a 0,5 V pp square wave. It is VERY FAST. it contains 44 kHZ of samples, each sample is a 16 bits, so it is 16 square impulses, and two channels alternating. So we send 2 x 16 = 32 squares per each sample. Plus some other information embedded like end of word, and clock and checksum. So we have roughly 35 squares times 44,1 thousand = 1,543 million pulses per second.
From Furrier\'s theorem we know that the square wave is an infinite sum of sine waves of odd harmonics, so if 1,5 meg is our first fundamental frequency, we need at least 10 harmonics to be represented properly to make a square. This means that we need to send precisely the sine wave bundle which includes clean 1st, 3rd, 5th, 7th, 9th, 11th, 13th 15th and 17th and 19th harmonics
The 19th harmonics of the 1,5 meg is 30 megahertz. That is bloody fast, as fast as radio waves.
It means that there is a big demand on cable quality. What is cable quality? Simply speaking, in order NOT TO attenuate the fast signal the cable must have very low capacitance and inductance. So it must be twisted pair with physical separation of wires and good low loss dielectric. XLO way of twisting springs to mind. Twisted but quite far apart. Third wire - earth - is sent by a separate third wire or screen. The shorter cable the better. XLR made of CAT6 cable should be the best DIY option.
IS2 interface is an option which sounds superior on all equipment which has this option. It makes the data slower, the signal is split into three separate threads: actual data, clock and left-right word separation impulse signal. So we need 3 wires plus earth to send I2S but it is worth it. The SAA7220P/B chip has this format readily available, as well as all receiver chips. It is usually done by means of using computer 9 pin serial RS socket and a computer LAN cable.
