Internal Wire Gauge?

Based upon advice from either John Curl, of John Risch (forget which) I ended up using 18 or 20g solid core (SC) for the ground runs/busbar in a vintage pilot 240 (the 26g SC that I first tried was noisy).

I used 26g SC (47 Labs OTA) for the signal paths and it worked well.

I left the original stranded power wire intact, so don't have an opinion on that.

This said, there was guy advocating Huge gauge stranded wire off the OT's in DH/SET amps (maybe 8g-10g), so my guess is that it depends upon the specific amp (PP with gobs of feedback VS DH/SET with none).

So...

You have ground/power/signal paths in the mix to figure out what seems best (for each) for your specific amp.

DeKay

Addendum:

One of the John's is a Jon (sorry forget which, but both have given me sage advice in forums over the years - which was much appreciated).

DeKay