Digital And Analogue Cables

@ghasley Digital cables are basically intended to transmit square waves of sorts, right, and not a full analog audio signal (despite whether you classify those signals as analog, they do not contain the analog representation of the music)? Yes, all cables have conductors that can send either type of signal, but the interfaces in which they connect and the spec that they need to transmit the information effectively determine their classification.

@Op I may be simplifying too much.

Analog cables

• Speaker cables
• Interconnects - RCAs or XLRs carrying analog signals between components (analog outputs from a DAC, phono stage, preamp)

Digital cables move digital signals - I have a network player/preamp so it’s all in one box. And many folks have separate components for streamer, DAC, Clock and music libraries connected using digital connections.

• This is where I think it gets confusing because there are a variety of USB, Optical, Coaxial, HDMI, AES and I’m sure there are others

@blisshifi

I was trying, rather poorly I might add, to communicate that the analog representation of the digital waveform is a pretty fragile thing. Subject to noise, induced jitter, reflection, etc. Too many in our hobby believe its transmitting EITHER a one or a zero. It is transmitting a representation of but it isn’t like say a ribbon cable between a hard drive and a mother board. The cable quality and specifications matter and can positively/negatively affect sound quality...in short, all cables aren’t equal.

Again, your exemplary reputation precedes you and I know you counsel your clients accordingly, I was just trying to make certain that a budding audiophile wouldn’t make incorrect assumptions. Regards.

So… a digital “cable” the wire part, not speaking on the connector, does not need carry but minimal voltages in a narrow range, but noise (interference) is of much higher concern because, as the signal is “low”, any interference is going to be “high” relative to the signal.

With a full spectrum, higher voltage signal, “analog”, the density and power of signal is higher and so the “interference” is vanishingly small (given the same interfering signal as above).  

Increasing the signal value relative to the interference value is a different beast depending on what type of “information” and at what “strength” and “density” that signal is.

Analog signal carrying fat pipes with some shielding (impedance as low as possible) vs digital signal carrying thin “pipes” with heavier shielding with specific line impedances per specs for the transmitters and receivers depending on what they are doing.

which is why optical cable is superior as shielding that from anything that can interfere with the light stream in the cable is much easier than shielding “regular” signal from emf interference. (And the specifications for optical is a .. more dense… info stream)

also why interference coming in on the power input is of concern.. there is no information, so any interference signal that is picked up has an outsized influence on signal as that interfering signal becomes part of the base of the carrying wave produced in the audio stream.

at least that is my layman’s conceptual understanding.

@blisshifi you hit the nail on the head. "Digital cables" transmit packets that are mapped to 0's and 1's with a different voltage levels and those voltage levels vary continuously during the transmission, due to power fluctuation, EMI, and various other influences. RCA single ended interconnect does the same (in all honesty it is questionable whether RCA cables can do sine wave without distortion, no jagged edges), transmits voltage variation. I haven't heard that someone is referring to Ethernet cable as digital, and it does exactly the same thing. It seems that it was pushed through via cable manufacturers to market cables as digital and sell them for digital music easier. In technical terms, probably the closest to a digital cable is optic cable, light=1 no_light=0. Another bone for us HiFi hobbyist to chew on.🫣