I would not say the QED cables were boutique, yes they was more expensive then Amazon Basics Cables I was using but the basics cables were not playing ball with my Dac/Streamer Coaxial/Digital inputs.
Well, "fairly expensive" sounds "boutique" in my world.
But don't take my comment too seriously, each to their own.
I cannot tell from your previous postings if you are aware of this, so please allow me to explain: You should
not use analogue RCA audio cables for digital S/PDIF connections, even if the devices have RCA "coax" inputs and outputs (where
coax really just describes the cross-section of the most commonly used type of cable for HF transmission). The signal carrying the digital information is an analogue high frequency signal and need a cable with a well defined characteristic of 75 ohm, very much like most antenna cables. Regular audio cables might work to some extend, but since the characteristic impedance does not match the impedance of the input and output, reflections from both cable ends can corrupt the signal and cause errors.
Amazon claims coaxial construction and compatibility with S/PDIF just for their Amazon Basics subwoofer cables, but they don't explicitly state the characteristic impedance to be 75 ohm, as required. Long story short, I do not necessarily recommend Amazon Basics cables for coaxial S/PDIF. But I also wouldn't spend more than 100 bucks for a coax cable. There are much cheaper cables that are perfect for the job ... and their RCA plugs will even fit the Ultra. One example:
For analogue connections e.g. the inexpensive REAN RCA plugs by Neutrik are pretty much perfect. Other Neutrik plugs should fit fine as well.
So, don't get me wrong. I do
not argue against changes to the recessed sockets. The more compatible, the better. I just don't think RCA plugs have to be of dimensions that currently don't fit.