Inspired by Black Sabbath's Iommi's Laney Supergroup amps and Rangemaster treble booster, the Sabbra Cadabra may well be the final word in nailing Iommi's tone from the foundation rather than the aftereffects. The Sabbra Cadabra can be run at up to 18 volts, which increases headroom and gives a sharper attack. Alternately, the unit can be powered by a starved power supply or weakened battery, down to three or four volts. This will soften the tone up significantly, but the changes are certainly significant. Give it a shot!