I’m sorry to hijack this forum for a completely different product, but the Novation moderator rejected my post as spam! Please remove this post if I’m totally out of line here…
Anyway, my drumstation has a crazy knob. The pitch knob for the hi-hat acts like a ghost is turning it up and down constantly. If I play the sound not controlled by the front panel (by switching the 808/909 switch) it works fine so I’m fairly certain it’s not a MIDI issue. Should I replace the pot? Has anyone ever had a bad pot generate constant crazy values? If so what was the fix?
Is it an encoder or a potentiometer (does it have infinite rotation or not)?
In my opinion, 2 main possible reasons:
- bad contact within the pot/encoder : some “contact spray” should solve this, in the worst case you can replace the pot.
- the tin solder has “evolved” due to the ROHS norm, or some dust is conducting. This one is pretty difficult to spot. The best option being to clean the circuit with the help of a toothbrush and some acetone or methylated spirit.
It’s a pot, not an encoder. Thanks for the advice. I’ll crack it open soon and see what I can do.
I think the DrumStation predates ROHS and would vote for oxide in the pot. And go for a good contact spray, not the bottle of WD-40 or 5-56…
I have Caig fader cleaner. The behavior is still very mysterious to me. It’s not acting like a typical “scratchy” pot. It’s more like someone assigned an LFO to that parameter. I’ll have to make a video…
Maybe the Pot isn’t connected directly to any analog circuitry rather then being scanned with an A/D. If so the middle Pin is broken/has a bad contact the A/Ds input is floating resulting in random readings - just like on the Shruhti/Programmer…
The drumstation is a virtual analog. So I would imagine that is the case.
If the thing gets a bit warm when set on, you can also suspect a solder joint gone wrong. You can usually spot them visually.
Have to agree with the “middle pin broken”.
Played with it a bit more this morning. The randomness only happens when the pot is set around the mid point, from around 11 o’clock to 1 o’clock. Anywhere else it behaves normally. I suppose it must be the pot then? Still very strange to me that it gets these random values on a constant basis rather than intermittently - I programmed 16th notes and every hit was a different value. But then I don’t really understand the electronics going on here…
Sounds like a worn out pot to me… removing dust ,cleaning and lubricating may help, at least temporarily. There is a lot of info on the net, see, for example, here: http://www.musicradar.com/tuition/tech/how-to-fix-crackly-pots-and-faders-219973
I’ve done this a couple of times, it kind of works, but the problem is usually back after some time. I ended up replacing pot both times.
After power on, if you don’t touch any knob…is the edit led turned on (blink)?
As said before - rust dissolving and lubricating spray (Contaclean, Kontakt PR) is very good solution. Especially if there’s no replacement pots.
I’ve recovered my drowned Soundcraft SX this way. More than half of pots and faiders was rusty and totally malfunctioned.
I’ve sprayed CONTACLEAN inside them (you have to move/rotate them a little after spraying) and also sprayed it on pcb (rust causes shorts in many places). Nex day i’ve cleaned the pcb, move the pots and faders again and voila - it starts to function. Not all pots, but most f them. After month of use non working pots regenerated one by one. Now i have working console (which i got for free) for the price of spray can.
But if there’s only one malfunctoning pot and you can buy replacement - spray not worth the trouble
Today I started repairing the Polivoks
No sound at all, all pots are in very poor condition. And no way to get replacement. So i’ve desoldered all of them, than open their cases, sparayed with Contaclean spray. Also clean all switches.
After that all pots began to work (except two wich works with crackling) and synth too. But keyboard still in very bad condition. Some of reed swithces broken, and somwere is short so one note playing constantly.
It’s lot of things to to.
Want to say that Contaclean is musthave!
I had a bass station once, dodgy pots on that too! I replaced a bunch of sliders on an ooold novation controller once, novation were kind enough to send replacements free of charge…shoot em a nice email maybe?
I reckon those Polivoks pots would clean up nice when soaked in some vodka
I do not keep alcohol at home, sober for two years =)