On the Jorge Nolla clip, he's plugged in and running the sound through an amp. At first, judging from the sound, I would have sworn that he has a couple or steel strings on the top, mixed with nylon basses below. But then I figure he probably gets that steel-string sound by pre-twiddling the knobs.

Definitely a more piercing tone than one can get from bare, undiddled-with nylon trebles, even if one is playing with a lot of nail and very close to the bridge.

That bit on the oud sounds pretty good.

Don Firth