It's those big, thick strings that they put on them basses! EVIL!!
Seriously, I'm glad to hear that you're enjoying the pedal so much.
I would be remiss if I didn't point out that BYOC makes several kits specifically for use with basses. You might want to check them out some time:
https://buildyourownclone.com/collec...***-chorus-kit
https://buildyourownclone.com/collec.../bassoverdrive
https://buildyourownclone.com/collec...rcle-bass-fuzz
Not specifically for bass, but works well with one:
https://buildyourownclone.com/collec...roducts/paraeq
https://buildyourownclone.com/collec...and-compressor