I just ordered a replacement for the Kelly KBL72401B in my C124 - which while working, is acting up. On top of my previously reported regen issues, motor noise has been very gradually increasing very slowly but surely - the only way to tell is that I've come to perceive the the once-pleasant rising turbo-like whine a an an annoying vibrating buzz until going quite fast. Also, my old e-max - which I used to consider noisier than the C124, is now in comparison, nearly silent.
The new controller with the "E" suffix is supposedly much quieter and smoother. (Per Terry at Current) It has different dimensions - 47mm shorter, 16mm wider, 22mm taller. Might need to modify the heat sink a bit.
I will need a RS232 to USB adapter cable to configure the controller. Anyone got one to loan or sell? PM me if you do. Thanks.