Check the listing for details. Carl Martin BassChorus Effects Pedal Black. Condition: New. Listed at 389.00 USD. Although similar in function to the Chorus XII, the Carl Martin BassChorus effects pedal is housed in the new wider/lower metal housing with “chicken-head knobs” for adjustment. The new housing also encloses the regulated +/-12V power supply for maximum headroom and clarity. While many chorus effects in the marketplace are designed for guitar use and therefore mid-range heavy, the Carl Martin BassChorus has been extensively fine-tuned so that the full effect of the chorus is evident as far down as low B. Similar to its predecessor, the BassChorus is a dual-stereo effects pedal with independent sets of speed and depth controls. The Select button allows you to use or bypass the effect and the On button allows you to choose between your two chorus settings.