Amp Internal Wire

I'm not getting into the debate over conductor material but would recommend Teflon for the insulator.  Why?  High melting temperature so less likely to damage it while soldering and then there is the whole low dielectric absorption thing.

Well the melting point seems like it should be the last reason to use teflon.

The teflon dielectric constant (k) is ~2, and I think that PVC is k=~4.0.
Cotton has a k around 1.3-1.4

K=2 is a lot lower than 4, so that is a good (and better) reason to use teflon over PVC.

like the Navy’s AEGIS cruisers. Teflon coating provides heat-protection for decades, where common PVC-coated wire will crack and degrade over time. 

There is some degradation from UV, drying out, and maybe other things.

How much heat is generated in the tube equipment? The insulation only needs to insulate the wires electrically. They do not need to be insulted for heat and cold, like a wool jumper, or down jacket.

And they do not need protection from heat. The insulation is to protect them from arcing or shorting.

It is not like the amp is mission critical, or crashing over waves 24/7 in a way that requires the insulation to not chafe over time.

I would still be using the teflon before I would use consider using PVC, just not for the reason of heat protection.

@nonoise @thyname . Yep

OP:

I am very familiar with the wire you are thinking about and can tell you it is wonderful. My favorite in fact. I have a lot of it in my system but have never rewired an amp with it.   

My guess is those internal amp wires are too short to make a difference and you might do more harm than good removing them and (poor) hand soldering new ones.

But if you like to go for it ... don’t forget the wires inside your speakers. Depending upon their size there may be more length there and you may be amazed, after you just got your $5000 speaker cables, what standard wires inside the cabinets you have attached them to.

I agree with those who are saying enough is enough. On my speaker designs, I use a better quality wire inside of them than most Major manufacturers do, but that is even overkill. A couple of years back Belden did a study and claimed that their CAT5  wire was quite sufficient for Audiophile grade connections up to 10 feet. and you are concerned over 4 inches or less?!?!

Now I might not agree with Belden, but that is what you will find inside speakers for less than $5000 in many cases. ANy High-End Company worth its salt has done its homework and knows that we are talking about things here that are so far beyond being measurable it is ridiculous.

My custom built 300B SET monoblocks has OCC silver internal wire and same for output transformers, I did replace a couple internal wires with Duelund dca for a bit more warmth. My speakers wired with combo Furutech and Duelund dca, Jantzen solid core and litz inductors. I've been experimenting with wire for years, with many components and cables, to claim it doesn't result in changes in sound simply means you've never attempted it.