Finally a doepfer module with some clean knobs and not like the absurdly enormous previous knobs, easy to turn, easy to take them in hands and you have ample space to turn them quickly in opposition to the previous ones where you had not even the place to turn you knobs without hurting your fingers. I also use the A138m but this one really lacks space for an easy, quick and effective turning of the knob in opposition to the A138s. You really get a make noise/harvesterman-Like knobs without the color which should be the basic knobs of the whole A100 system's modules. the A138m, the A138s can mix CV signals and lets you feed them to your different CV inputs of you other modules. You can feed up to 4 different CV sources or audio sources to CV inputs, monitors, mixers or wherever you want to patch to output. You also got the panning to play with, or to use for your mastering. With this module, you get all the advantages of a doepfer module, which is cost, solidity and effectiveness without those damn knobs which are killing my fingers on a daily basis. I strongly advise you the 138s.