Reader Matt Mateo writes: “I think I may have an issue with my APC40 crossfader. When I move it to the left I can here the music from the right channel and the left channel. It acts up a lot but it clears up when I move it back and fourth a few times. I’ve been reading online and it’s a common issue with some people. I’m writing to ask if you’ve got any suggestions? Is this a Midi signal issue or is it a defect?”
Digital DJ Tips says:
It’s almost certainly mechanical. In the “old days” knobs and crossfaders were basically what are referred to by electrical engineers as “variable resistors” – the signal actually passed through them and they had material in them to attenuate it, so less or more came out the other end depending on where the control was set. While this is not how it is usually done with modern electronics (nowadays the electronics “look” at the crossfader setting and applies this to the actual signal instead), nonetheless there is still mechanics involved and so contrary to popular opinion, mechanical issues can still affect the way the circuitry “reads” the crossfader, and so what you ultimately end up hearing. (By the way, if you’re unhealthily interested in the myriad types of crossfader out there, DJ TechTools carried a crossfader article detailing them recently.)
So what to do? In my experience, doing what you are already doing can help (if I get a “dirty” sounding control I move it 100 times hard in both directions and it often sorts it out for months to come), but also compressed air or electrical contact cleaner can fix things too – they come in aerosols with tiny tubes that attach to the top to allow you to poke them right in where the problem is.
Of course, in the case of your APC40 the crossfader is replaceable, so that’s another option.
Over to you: How do you sort out crackly, dirty or malfunctioning controls on your DJ equipment? Got any tips, tricks or products that always work for you? We’d love to hear your experiences and get your advice in the comments.