The DUAL DRIVE is not an ordinary overdrive. It's a preamp which is to be connected with a clean preset or single-channel- amplifier.
It turns any single-channel amp into a three-channel-amp. Its distortion is similar to the sounds otherwise gained only with high-prized boutique amps which may cost up to ten times as much as the DUAL DRIVE.
Many users claim the DUAL DRIVE sounds better than many tube amps, at least just as well.