Hi ET,
I wanted to post these comments, but please understand my motive is to educate, not criticize. Your magnet wire setup is simple in design and no doubt sounds cleaner without the shielding in most cable designs. It is not however because you have no dielectric, in fact the enamel coating on the wire you are using has a relatively high dielectric constant of 5.1. A bare wire in a vacuum would be a 1.0 and bare wire in air would be slightly higher. Cotton and dry paper have fairly low dielectric constants of 1.3 and 2.0 respectively.
The problem with copper wire in air, cotton or paper is corrosion and oxidation. Cotton and paper will both retain moisture in a humid climate and actually speed up the oxidation process. This is where poly___ something and Teflon become so useful, but as discussed here, they carry a sonic signature with them. The solution of enamel coated copper wire seems so logical, but in fact it is not a great dielectric at all.
Dielectric constant is a measure of the charge retention capacity of a medium. In general, low dielectric constants (i.e., cotton @ 1.3-1.4) result in a "fast" substrate while large dielectric constants (i.e., Alumina @ 10.0) result in a "slow" substrate. What this has to do with our audio industry is obvious. The lower the dielectric the less energy retention and the easier the signal is carried.
For this reason copper in inherently limiting if we want to use low dielectric materials to isolate wires. In this respect a super thin poly__ something would actually be a better choice than enamel. The issue then becomes finding a super thin covering on copper wire. This is not as easy as one might think, but there are thin tubing that can be shrink wrapped to a bare wire that may prove to be an excellent choice over enamel.
So I suspect the real reason you are happy with the sound of your system is two fold, first the fact that the wires are allowed to be free of added materials like shielding fillers and sleeving leaves a cleaner signal. The high dielectric constant you have may actually have some benefit by being slowed making the treble less aggressive, thus less bright.
jd