Help Me Explain Power Cables to my Guitar Friends

Interesting thread.
Ghostrider is correct that the desired sound out of guitar amps is antithetical at times to what we try to achieve in audiophile land.

I would generally suggest just trying a 14ga Volex (6$) in place of whatever 16ga or 18ga stock thing they are using.
If they are using an amp that is a solid state or digital modeler design-they should notice a lowered noise floor which allows their tone/sound to be heard better. They will be convinced as it is all about sound in the end.

If they are using a tube amp or SS/tube hybrid they should still hear some difference. Whether they like it or not is up to them.

I use a LINE 6 combo amp and POD XT modeler and and use the simple 14ga Crump DIY power cord on my combo amp with good results.

Very simply-just bring a cord over and let them try it.

I also use a custom Evidence Audio guitar cord from my guitar to the amp.
My belief is that better cords/cables allow me to hear the guitar/amp or modeler created sound better.

Markphd wrote - I think you are right, but I think where audiophiles can fall off the turnip truck is to equate difficulty in interpreting measurable differences (tubes vs solid state)to lack of measureable difference ($1000 pc versus WalMart). In the case of tubes vs transistors, the measurable differences are obvious, and learning to understand the relationship between listening pleasure and the two different characteristic distortion signatures has advanced the state of the art. Data is good!
Happy Listening!

Forget it. My musician friends dismiss high-end audio as bunk. Wire is wire in their opinion. Good luck.

I have been a guitar player for 30+ years and into audio since the 1970's. Yes, I can still hear the subtle differences! I have even had my hearing tested over the years. I upgraded the power cord for my Marshall JCM900 50 watt reverb top, running through a Mesa 4 x 12 slant cabinet (guitar lingo) and I can hear the difference in dynamics, sustain, and "chunk" in the sound. That is true whether I am playing my American Reissue '62 Stratocaster, Buck Owens Tele, 1989 White Les Paul Custom, or Paul Reed Smith Custom 24. Many companies are making "high end" guitar to amp cables now, including Monster and Tara Labs and DiMarzio. To me the differences are the same as audio applications in terms of improved frequency response and harmonic content. Show them my reply and they can tell by the gear that I take the guitar stuff seriously. You might need to point them in the right direction as to what to listen for. One thing about most guitar players, whether the guitar sound is distorted or not, they know when a type of guitar's sound is being accurately captured on a recording. Good luck!

While I absolutely agree that the vast majority of claims for power cords are absolute nonsense, when I brought home my Marchall amp for the first time there was a loud oscillating hum. Back to Guitar Center it went, where we couldn't duplicate the problem. They gave me another one anyway, and it had the same problem.
Ultimately we found that I had a wall wart power supply in close proximity to the power cord, and moving them far away cured the problem.
Just be sure your cord has good EMI/RFI (anything reasonably well shielded) and your good to go.
Or get one of those $4,500 "soundstaging champs" for a real guitar amp epiphany. Sure