Some thoughts about tonearm wire

Spatialking, I strongly doubt that the wire in your tonearm is as thin as 50 AWG. 50 AWG wire is approximately 0.0010 inches or 0.0254 millimeters in diameter. Typical tonearm wire is 33AWG or thereabouts.  There used to be a school of thought among audiophiliacs that favored solid core wire and with a gauge as thin as practicable.  Michael Percy Audio used to sell and maybe still sells a special brand of Japanese 6N copper wire that is 40u (microns) in diameter, or .0015748 inches, which means it is a bit wider in diameter than your estimate of what you see in your AT tonearm.  I have seen an IC made with that 40u stuff; it was almost invisible and incredibly fragile, enough that the company that made it, Mapleshade Audio, gave up on it. Anyway, as others have said, I would leave the wire in your AT tonearm alone, if it were me making the decision. 

Also, you state you are worried about resistance, capacitance, and inductance.  By and large the gauge of the wire will only affect resistance per unit foot.  The geometry of the winding, if any, is what mostly determines reactance (capacitance and inductance). If the individual leads are twisted together, for example, that would affect reactance as compared to running the 4 leads (left, right, hot, ground) side by side.  Solid core vs stranded wire would also make a difference in reactance.

By the way, if anyone has a meter that can measure down to 80 milliohms (.08 ohms), let me know. I’ve owned many different ohmmeters including the best of both analog and digital, and none can measure below 0.1 ohms, more usually 0.2 ohms, and that’s with the two leads touching.

@lewm There is no way that tonearm wire is as thick as 33g!  One can see the insulation, but one cannot see the wire inside it when looking at the end cut. I have a wire stripper that can strip down to 32g, but that insulated wire slips right through it.  

As for wire gauge affecting only resistance, that is not true.  The math for calculating inductance is complex, but you can find inductance calculators online to determine the inductance of a wire.  The bandwidth numbers I posted above are just from that calculation. 

Also note that wire has a surface area just like capacitors.  Put them closer together, the capacitance goes up.  Make the surface area larger and the capacitance goes up.  Move them apart, capacitance goes down and inductance goes up.  The fact is, resistance, inductance, and capacitance are linked together.  Changing one will alter the others.  

I do have a milliohm meter in the lab, and it uses a 4 terminal Kelvin measurement.  It can easily measure 0.001 and 0.0001 Ohms.  The catch is it pumps 10 Amps down the test subject, and it measures the voltage drop to display milliohms.  If I pumped 10 Amps down that tiny wire, I am sure it would smoke it!  Frankly, I would be squeamish about sending a 1mA as a test current.  The only way I could measure the resistance in that tonearm is to determine the lead resistance and subtract that from the reading.  Indeed, a process fraught with errors.

The best approach would be to just replace the wire with a known & larger gauge  I can't do this in the lab, and the quotes from folks who can do this is more than I want to spend on the project.

I did not say a length of wire does not have inductance (or capacitance).  I did say that the gauge of the wire has little effect on reactance (thinking of a single conductor in space with nothing around it), compared to the geometry of the wire in relation to other conductors that might be carrying either ground return or the opposite phase of a balanced connection, in an IC or inside a tonearm wand, where you have two hots and two grounds running close together in the case of an SE circuit or two positive and two negative phases, if the cartridge is running balanced mode.  Twisting increases C, and running them side by side might increase L. Also, the wires inside a chassis can affect each other’s reactance depending upon how they are routed with respect to one another. The effect of those factors on capacitance would outweigh the difference in capacitance between two very thin wires of slightly different gauge singly in free space, or at least I think so.  If you have some data, I would be interested to investigate this further.  

Most of us by and large do not have access to your lab equipment.  Therefore, when you say that resistance should be less than 80 milliohms (I think that is an accurate paraphrase, but if not, please correct me), that is not a useful criterion for the rest of us who cannot measure down past, really 0.2 ohms.  I have expensive Fluke digital and Triplett analog meters, and neither can go that low. My Fluke meter reads 0.2 ohms when the two leads are in contact.  Furthermore, the slightest bit of dirt, grease, or whatever on the probe would screw up the reading of 80 mohms.  I also did not mention it before, but why or how did you settle on 80mohms as the max permissible resistance?  Just wondering. I have thought on this issue myself, once in a while. Many gain stages use a resistance in series with the grid of the gain tube or the gate of a transistor, in order to suppress oscillation of the circuit.  In a tube stage, the value of such a resistor is usually at least 100 ohms. I wonder how the resistance of the wire carrying the signal to one end of the "grid stop" resistor could make much difference in light of that fact.  I am agnostic, unsure what to think about that.

Forgot to mention that if you think your tonearm wire is thinner than 33G, based on direct inspection, I stand corrected.  Must have been a bear to solder that stuff.

@jc4659 I have experienced works undertaken on the Mechanical Interfaces and as time went on diverted the focus onto the electrical side of the same TA.

After a selection of designs and wire types tried. 

A certain wire used continuous really shone through for the attraction brought with it. 

It also left the impression the work undertaken on the mechanical interfaces were now really able to show off the quality they had created. 

I fully understand your reaction to your own experience. 

Femo's of such designs wins advocates fast.