It doens't turn it into a DM-3, but it makes it nice and dark. Adding the cap does reduce the mumber of echos though, so if you are looking for an infinite echo sound, it won't let you do that.
i am looking to get a warmer sound out of the pedal like keely has what cap do you recommend?
Keeley shows it switchable between 0.1 and 0.47, but 0.1 didn't do "enough" and 0.47 did "too much". I used 0.22�F and it sounds good to my ear - YMMV.