You are probably the first to report what sounds like a "significant improvement" as opposed to "marginal", by using better wire for the neutral, but then is is UP-OCC copper, which appears to provide benefits no matter where it is used. Others have tried very good wire from a couple of established brands, but not UP-OCC copper, and they reported only marginal improvement.
I think also that all cables have a tendency to perform differently from one system to the next, because your description of "invisible" speakers and the sound being more "vinyl like" (I’ll assume this means more natural/realistic) is exactly what I am currently experiencing, but all my cables are using the Silver plated Mil-spec from Take Five audio, which is CRYO’d
It stands to reason that using the best quality wire for both signal and neutral conductors should achieve the best performance.
So, do you have any plans to convert other Helix cables?
@traubert - ever since I started developing cables I have come to realize that any change can make some difference (good or bad) in cable performance, so it might be possible to "tune" a cable to a persons preferred sound. What I will add is that the Helix Geometry is one of the most neutral sounding cables around and as such the "tonal qualities" do not change too much
What I and others have tried is varying the number of conductors of the same size - and from that perspective two conductors appear to provide optimal "bang for the buck"
e.g. going to 4 wires made no appreciable improvements
Unfortunately, budgets are the restricting factor for most people participating in this thread, but if you are interested in following up on this particular approach we would all appreciate your feedback/findings
Regards - Steve