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I think I've got genuinely failed pots on my ESX. I'm familiar with the jitter issue and it looks just like that except I've already done the baker's paper and it's not helping, plus it's always the same two, maybe three pots.

FX1 and LFO rate values jitter, but I can make them stop by turning them all of the way to the left and leaving them there. Cutoff is different, sometimes it will only go up to 40 or so. The pots turn smooth and don't wiggle.

In addition to trying the baker's paper fix, I also dosed them with a healthy spray of Deoxit which makes them spin more freely but didn't change the behavior any.

I bought it used of course but it's in super cosmetic shape, came with the box and whatnot, and there's not a scratch on it.

Before I start looking for part numbers and a soldiering iron, has anyone seen this and come up with a fix?

Thanks,
CCQ

have you tried tightening up all the screws holding the control surface board the the front face? I had knob jitter issues mostly when pressing buttons and especially when using the arp ribbon. I didn't do the baking paper thing because I thought that the spikey solder points would just poke thru it anyway in time. tightening up my screws fixed my jitters.

Yep, the screws thing worked for me on my EMX for a time so I did try that. Rather than solder, I'm going to see about soaking these pots a while. Too bad, that.

There's a post referenced from the knobs sticky titled 'FX knob on SX' or something like that and I got optimistic but i think the title's a typo and the fix is for an encoder.

I ordered replacement pots from Syntaur and they arrived fast (and cheap) from Texas. Some of the pots have surface mount parts next to them but in the case of the two I'm replacing, they're easy to get to with a soldering iron.
-CCQ

Did soldering new pots make a difference?

Yes and no. There are little surface mount jobbers next to each pot which make getting the middle pins sorted a tight and treacherous squeeze. I wouldn't want to go and do all of them for kicks. You're bound to mess one up. Speaking of messing one up, I messed up the cutoff which is going to take a little solder magic which is going to have to wait, but I'm optimistic. Good thing I have two.
And thanks for asking.

I don't think that soaking the pots will help. It sounds like an electronic glitch or short somewhere & the pots are likely just the symptom rather than the root.
Potentiometers are lubricated & using cleaner is not a great idea unless they are genuinely dirty. If you have used a cleaning fluid, i recommend to follow up with a blast of compressed air, a wipe clean & a re-lube . The cleaner you see washes out the lube !

One other thing, was it an ebay purchase ?

Thanks, Doc. I bought two in a week. The Ebay one was in good shape. There were some dents to the bezel which were noted and fine with me. This one was a Craigslist purchase, otherwise immaculate, with the box, etc, and checked out OK. These things always seem to pop up after.
Is using the Deoxit lube atonement for the sin of cleaning them or am I better off not using Deoxit in the first place?

CleverConQueso wrote:Is using the Deoxit lube atonement for the sin of cleaning them or am I better off not using Deoxit in the first place?

Can't say exactly & i'm no pro. Plus i have not laid hands on your units but assuming they are a few years old i guess it can't hurt to blast 'em out a bit. Just clean up any excess fluid & remember , by cleaning them you are also washing out the original lube. Or is you product clean & lube or something ?
I doubt it will make matters worse though, a process of elimination if nothing else.

So you still havn't got to the bottom of it yet then ?

I reckon the trouble with buying used gear is (And always has been) that people just know that they can offload it onto someone else & still get a good price. I've experienced it myself , bought a synth & it turned out to be twitchy but was a twitch that was blatantly obviously known to the seller except they withheld that part in the description !! It goes on all the time & we have to be a good judge when we take the 'Second hand risk ! "

Best of luck with it, hope you find a fix.

Well I went and replaced the bad pots and they're better now except one. The saga is buried in the thread above. But yes, I have the cleaner/lube kit.