Did this mod last night. I almost didn't do it because the fab echo actually sounds kind of cool even though it is very limited. I figured $15, I will go for it. I am really glad I did.
I re-housed the pedal into a new enclosure to make room for the knob and because I plan to add an LFO possibly for modulation eventually. Clipped the switch wires and hooked them up to a momentary spst pushbutton (any will do).
It actually sounds pretty sweet. I used a 100K pot. You do start to hear some clock noise at the longer settings, but the delay itself still sounds ok - a little grungy, but ok... It sounds really good, smooth, up to that point. Each repeat is colored in a nice way. Very dub sounding.
You have to really watch out with those SMD resistors. If you touch one with your soldering iron, you can pretty much kiss it goodbye. I don't know if you were supposed to remove the resistor (by the cap leg) for the infinite repeats mod, but as soon as I touched it, the tiny thing stuck to my soldering iron - so small I almost couldn't see it on there. I just bridged it with a solder blob, and it works... so... no complaints but a close call maybe... wouldn't want to touch any that you weren't sure about... I used some hot glue in a couple places for the stress relief on the wire for the delay time mod pot... that's that...