Harps and Accessories
I was fortunate enough to be able to do Pirastro pedal nylons for the 4rth Octave (Burgundy gut in the 5th) just to try them.
As far as I know, it is an industrial secret. They are made of different material, have a different surface. And if you play low on the string, they do sound quite the same as gut. What’s best is if you can get the heavy gauge strings.
Saul, by heavy gauge, do you mean Pirastro Pedal Nylon or is there something else?