Has anybody tried using single solid core cables?

A comment on a quick method of "what is the gauge of TWO of the same wires"..
Generally in the audio use range two same gauge wires add upto the third less gauge number.
So two 25 gauge wires equal one 22 gauge wire
Two 22 gauge wires equal one 19 gauge wire
Two 19 gauge wires equal one 16 gauge wire..

Two 15 gauge wires equal one 12 gauge wire.

FOUR 25 gauge wires would then be like one 19 gauge wire...

This is for same types.. Solid core, to solid core etc.
As Almarg used the tables for the resistance and ampacity give this generalized result. easy to use.

I just switched from stranded #10 carol wire to #12 solid core for some power cables.
There is a difference.
The carol stranded had a big robust sound.

The solid core had more inner detail,I noticed little things that were buried with the stranded.

I am sticking with the smooth but detailed sound of the solid core.

Solid core copper and stranded copper do not sound the same.
Solid core DIY speaker wire had less bass but the treble and mids were much more defined and less tizzy.
I could always hear a difference when I used each type of wire as DIY bypass fuses.

The solid core DIY fuse was less harsh than the stranded.

I no longer use DIY fuse bypass devices, as there are replacements for the stock fuses today.

Yes, I have experimented with solid core copper and solid core silver cables. The sound is unnatural, but it can make vocals sound better than they are.

I've come around to thinking it's all in the implementation and the particular system. Right now, I have solid core silver for my ICs and tinned, stranded copper for my SCs.
It's the best I've heard in my present system.

Coli, interesting personal observation on the unnatural sound and the betterment of the human voice. I know from recently using silver solid core SCs that voices were better presented than most other parameters of the musical event and that leading edges were hightened at the expense of the rest of the note. That could be why it was so engaging, at first, and then left me unsatisfied after.

I still believe that there are better made solid core SCs out there but they are beyond my financial reach.

All the best,
Nonoise

A good solid core cable can be competitive with a midrange stranded cable. But in the upper levels of performance, stranded cables rule. Some would say that the top level solid core Audioquest is competitive with the best Nordost, Cardas, MIT, Purist, but that's not my experience.