Hi, I am trying to get a tone close the basic tone on the first five Black Sabbath albums. During this period Tony Iommi was using a Laney Supergroup head boosted with a Dallas Arbiter Treble Booster. The closest thing to the Laney on the HD 500 is probably the Plexi, any ideas which of the pedals would give a boost similar to the treble booster? or has anyone achieved a good Sabbath tone in some other way? There is very little in Custom Tone, and to my ears they don't come close to the Iommi tone.