How does Synyster Gates do pitch squeals?

Answer 1

Depending on the placement of the note in the particular solo or scale run, he usually uses a pinch harmonic, basically catching a harmonic with a piece of flesh from the thumb of the picking hand.

Also, the pitch squeals could be attributed to the electronics in his guitar feeding back. He is currently using a Sustaniac pickup in the neck position. The Sustaniac is basically a sustainer, which gives him a variety of tonal options and he can set it to deliver a specific type of feedback, such as a lower octave, a sustaining octave or a higher, more feedback delivering octave, such as in some of the riffs and solos, Listen to the Nightmare record, it is absolutly filled with them, such as the opening piece on "God Hates Us." I believe he also used it on some earlier pieces, as early as "Seize the Day" from City of Evil. He uses it currently, as shown on the Live In The LBC dvd.

and yes, i have pretty much geeked out both setups of Synyster Gates and Zacky Vengance. I am a huge fan and a fellow guitar player. I hope this info serves you well