Well the first thing I noticed on the s4 was the bad faders and how stiff they are.
I used to play on a Rane ttm57 so its a HUGE difference. But I can live with it since I like the s4 so much.
Im just hoping this doesnt happen to me. Goodluck.
Workaround FIX
I am experiencing a software glitch where the software track volume faders glide around while the controller faders are at their extremes. Upon moving them 1-2mm from their extremes, the software volume reengages. This glitch does not occur while the controller volume faders are positioned anywhere within that 1-2mm range.
I have owned two Kontrol S4’s each with the 3rd party fader, voiding any warranty either had. One S4 was purchased at its release off eBay NI and the other direct from NI at $161 replacement charge when I first experienced this issue.
It seems that the plate the volume faders sit in deform over time allowing the faders to step out of an operational or understandable controller range for the software. A workaround, which I have yet to try is to affix some kind of durable plate minimizes the controller range within those 1-2mm discussed above.