I tried six or seven coax cables as well. The worst was the entry level Synergistic Research Foundation. Warm, dynamic but had a very weird frequency response, lacked depth, just weird. However, their AtmosphereX Euphoria cable at 3X the price at $1.5K is everything that the Foundation lacked plus. Just fantastic and clobbered all other cables I tried (which were priced below $1K). Try it from an SR dealer with money back guarantee.
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?