Do I need an expensive digital cable?
I have been using a fairly inexpensive optical cable to connect my CD transport to my Moon 280D streamer. I was told that an SPDIFcoax cable would sound better. For an experiment I purchased an inexpensive Pangea coax cable. It didn't sound at all because its terminator ends did not fit snugly in my equipment. I consulted chatgbt who often gives me audio advice. It advised that for the short run of 1 meter, an RCA interconnect would work. It did. And sounded much better than the optical. Chatgbt said that RCA interconnect was good enough.
Now, there is a twist to this story that might make those doubters think twice. A digital cable carries packets of information that are rechecked to assure that the streamer is recieving correct information. There is the timing concern, though. But my Moon 280D has an asynchronous DAC with a clock as part of the DAC. Any information sent by my transport, whether it is clocked by the transport or not, will go through the Moon's asynchronous DAC's clock. So ;there shouldn't be a timing problem. Should there?
Can anyone make a case that I should buy a "better" coax cable?
@audio-b-dog understood. Thank you for that information! you used chatgpt you said in your original post. 1. what is bit depth in audio and 2. With cd transport connected to dac via coax cable, which unit is the master clock
|
True.
No, it does not. Unlike an analog signal, a digital waveform merely indicates whether a bit is on or off (1 or 0). Any voltage (amplitude) above a predetermined threshold means a 1. Any voltage below another predetermined threshold means a 0. As long as these thresholds are met, the bit will be set correctly and it does not matter how clean or how awful the analog representation of the waveform might look. Now, some cables might pick up EMI and RFI along the way, which might adversely affect sound quality if any of the connected components are poorly designed and / or built, but that is completely independent of the digital data transmission per se. |
@audio-b-dog With a USB connection into your Moon 280D, the data stream is asynchronous (untimed) until it reaches the DAC’s internal clock. With Toslink/coax/AES EBU/I2S, the source device (e.g. your CD player) holds the master clock, and the data transmitted to the DAC is synchronous (timed). Clock quality is most certainly a factor in the overall result, and another variable to consider as to why one type of connection to a DAC can bring a different result than another. The proper characteristic impedance for both coax cable and connectors is 75 ohms. Audio RCA connectors are typically 20-50 ohms, so a better coax cable will use connectors of the correct impedance. Proper impedance minimizes unwanted reflections. Where one is flexible about cable length, 1.5m (~5ft) coax cable length has been demonstrated as theoretically "ideal" for reflection mitigation. Splitting hairs possibly, but worth a mention. |
@richardbrand you do have to remember though that streamers buffer the incoming data stream in memory. TCP is a clock-less protocol: by design it does not have nor need a physical clock, unlike USB etc. which do. |
@devinplombier not entirely true. coax is a copper cable. It is susceptible to EMI and RFI. If subjected to either or both, the electrical noise may impact timing and interfere with data transfer. In addition the noise will make its way into the DAC which again will negatively impact sound quality. |
