H9 ZIMcard is currently the default for Channel B. A very high-fidelity and high-gain version of the TS circuit. Full bass, even mids, smooth top end. At low gain it's a great overdrive and at high gain it's in distortion territory. Double diode configuration in the clipping section enhances sonic clarity and low mids. H9 delivers the gain of a distortion with the voicing of an overdrive.