How crucial is the quality of a digital cable?

I recently purchased a Cambridge Audio CX 81 integrated amp. The analog inputs sound great, but I find the internal DAC to be a disappointment. It uses the ESS Sabre ES9016K2M chip. I use a mid-level Rotel RCD 951 CD deck as a transport via the digital coax. I also hooked the deck via the analog out, just to compare. The analog interconnects are entry level AQ's. The digital coax is an Amazon purchase in the $15 range. I find the internal DAC of the 20 year old Rotel to be superior to the new AX 81, when doing an A/B.

What then confuses me is that the Blue Tooth streaming from the amp is quite good. It is HD aptX,  24-bit/84kHz capable. But, wouldn't that also go through the same internal DAC? Could it be the mediocre Amazon digital coax cable? I always assumed that digital cable quality was less significant than analog cables. Just bits and bites, right?

If someone knows of a decent digital coax for under $50, I would be very grateful. I would also appreciate any advice on an entry level power cord for the amp. Can a decent power cord be had for under $100? 



Can of worms and some great advice above. If you upgrade to not using your phone as a source (dedicated streamer) and upgrade the DAC and cables you will be rewarded. And how  

A used LumimT2 is one such all in one device. (It supports native Amazon HD) it’s a great price point for what you get. Separates also great but will have a higher entry cost.

Also try a free Qobuz trail. 



I will give you two examples:

- On streamer to DAC I replaced a DH LABS SILVERSONIC  USB cable with a CURIOUS USB cable. Big difference, so much more musical, less harshness, smooth to the ears yet plenty detailed.

- latest switch, from CD Transport to Dac, I replaced a AQ Carbon 48 hdmi with the Tubulus Concentus I2s cable. OMG, unbelievable difference as soon as I connected it. So much better detailing with incredibly tight bass and a very airy sense of space, gorgeous.

You can see more details about the equipment on my house of stereo system.

Digital interconnects have had the biggest sound improvement in my system vs power cables as my listening house has a dedicated line with zero interference. So yes, digital cables upgrades make a huge difference but it is not cheap.

It’s a catch 22 mits not just the usb, or digital cable ,

but you have at least 2 Ethernet cables that too effect the sound quality 

the Ethernet cable closet to the hub makes the most difference 

the Ethernet hum too ,such as uptone audio ether regen around $630 

makes a noticeable improvement , the synergistic research is the best I have hear 

by a large margin but around $2k I will get one ,maybe  I spent $5k just in hub and cables ,and don’t even have the top Ethernet hub , Top Digital sound quality cost over $10 k ,the dac alone is around $5k and up.

Just bits and bites, right?

Well, yes. That is true.

As has been mention previously, the issue is not with the contents, but how it travels through the cable and if there is contamination or timing errors.

In many respects, both digital and analog demand decent cables, dependant on the system.

I've never used RCA interconnects to transfer digital signals to a DAC. But theoretically, cables which are most resistant to RFI/EMI would least likely to interrupt any digital signal stream. My first choice is to use optical cable because it's completely immune from RFI/EMI. In my experience, the results are error-free streaming from my Apple TV at it's highest spec digital steaming capabilityy, (IRC 24 bit 48 MHz and my Sony UDP 1000ES disc player at it's highest spec into the internal DAC on my Anbthe STR pre-amp. And so far, I've heard no difference in SQ from more expensive streaming system. I'm 71 years old/; but my most recent hearing test about four years ago reveled that I can still hear 20KHz audio signals. I consider myself extremely lucky because I spent sixteen years in ambulances running a high volume of emergency responses with loud Federal Q sirens and later, electronic sirens without wearing any ear protection.