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

@audphile1 

Here's what chatgbt had to say about the chip:

 

1) The DAC “ID” (the actual DAC chip)

The 280D’s D/A conversion is built around the ESS Sabre ES9018K2M DAC chipset.

That chip is used in a fully asynchronous design, with support up to PCM 32-bit/384 kHz and up to DSD256 via USB/network (depending on input).

2) The “ID number” in the manual (FCC IDs for the wireless modules)

If by “I.D. number” you meant the regulatory ID printed in documentation, the 280D manual lists transmitter module FCC IDs:

  • SSSBC127-X

  • ZUCSEDMP3

Extra useful info about what’s “around” the DAC chip (often matters more than the chip)

The manual also notes MOON’s jitter-control DSP approach (M-AJiC32 / MOON Asynchronous Jitter Control) and describes the unit as a fully asynchronous DAC.

Lets assume your moon dac is fully asynchronous. Which means even when it’s slaved to your cd transport via coax cable and the transport is the master clock, the moon will reclock the signal with the final result will be based on its internal clock.

Based on my experience with several DACs, some claiming to be immune to jitter, the quality of the signal fed to the DAC always matters and makes a difference in sound. Using USB allows for DAC clock priority and yet cables still matter and transports/streamers matter as well. 

A golden rule of GIGO (garbage in garbage out) applies in audio every time, analog or digital. There’s no magic bullet. 
 

And to your streaming sounding worse than CD - that’s most likely because your network set up can probably use an improvement. When you optimize streaming it will sound comparable if not better than CD. That could be a topic for the next thread you start. 
 

McCormack :)

brings back good memories. Had several of their amps. Great sounding stuff. 

The 280D’s D/A conversion is built around the ESS Sabre ES9018K2M DAC chipset.

That chip is used in a fully asynchronous design, with support up to PCM 32-bit/384 kHz and up to DSD256 via USB/network (depending on input).

@audio-b-dog Ok, I now understand what’s happening here. This description language is a product of its time, referring to this older, low-power ESS (portable DAC) chip as the first generation ESS DAC chip being able to operate USB asynchronously (ASRC), meaning with a separate USB interface chip and its own clock. This is nothing new in 2026, but was a novel development years ago because earlier chips used the jittery source USB bus frame clock as the audio clock. The digital inputs in your unit almost certainly function as any other DAC, and when using coax, you are using the CD transport’s clock, whereas with streaming, you are using the DAC’s internal clock.

Here is an old article (2013) with a good description of the source (e.g. computer) providing synchronous USB transfer.

@ted_b 

You are right. It uses an older ESS DAC chip, although I don't know if that makes you right about whether the transport's clock is used.

I will tell you one thing, I think the Moon 280 D was a deal. At least for me. It doesn't have a screen. The streaming interface is on an iPad or phone. It does not have a preamp or headphone amp. Just simple lights on the front telling the user the input in play and the quality (44.1, 48, 96, etc.) It does use, however, the same software as the more expensive Moon streamers. When I auditioned it I could not tell the difference between the 280D and streams costing more than twice its price. I didn't think I'd stream much, but I am doing more than I thought. I have heard better streamers, but this one errs in a musical way, kind of like tube gear. So, I'll keep it.