"I’ve been using a Mad Professor Simble pre-driver pedal when I need to drive the amplifier a little more. I think it’s a brilliant, simple pedal. It’s just got two options—loud and louder—and a footswitch."
beautifully transparent and complex overdrive. doesn't do extreme gain settings, but packs quite a punch into a decent clean amp. for massive crunch i tend to run a klon-type overdrive into it to give it a little more oomph.