In the video below, guitarist Jon Donais of Shadows Fall (He's also filling in for Anthrax these days) demos Rivera's Metal Shaman distortion pedal and Double Shaman overdrive pedal.
He plays the Metal Shaman through the clean channel of the Rivera Knucklehead Tre amp; he plays the Double Shaman's LA channel through the gain channel of the Knucklehead Tre. Both are running out of the Ktre and into a Celestion Vintage 30-loaded Silent Sister Iso cab. It was recorded with a SM57 straight into Protools Mbox pro with no additional EQ.
For more about Rivera amps and pedals, head to rivera.com.