TC Electronic 3rd Dimension: adjusting the bias trimmer

Thu Oct 23 2025
https://dim3mods.blogspot.com/
Here, I demonstrate adjusting the BBD bias trimmer on the TC Electronic 3rd Dimension, seeking the best available sound quality. Unfortunately, to my ears, the trimmer seems to have three positions: a range of about 30 degrees in the middle where the BBD works at all, flanked by regions on each side where it does not work at all (presumably, the BBD saturates). Within the "works at all" region, I cannot hear much of any change in sound quality; the best policy seems to be to simply set it in the middle of this range, and call it good. Is this good enough for me to tolerate, in view of my potential plan to interconnect two of these units so as to produce an actual dimension chorus? I'm tending to think not. But I had to find out.