Cleaning/Deodorizing a Second-Hand Clouds


I just learned the hard way that one should always ask sellers of used modules if they come from a smoke free environment or not. I got a clouds for a good deal, in good condition, but it reeks like cigarettes. I just quit last year, so this isn’t ideal for me.

I’d like to clean it up and deodorize it as much as possible. I’ve got 99% Isopropyl Alcohol to wipe off the surfaces, but I don’t think I should use it on the knobs, since alcohol is known to degrade rubber.

I also have a rubber cleaner from MG Chemicals that I use for cleaning the pinch rollers on my cassette decks.

Does anyone know if I could use the rubber cleaner on the knobs and/or have any advice about cleaning this module up?


Isopropyl will get you partway there. Get some deionized or demineralized water (same thing) and hit it with that. Most of the compunds in smoke dissolve in one or the other of those.

That’s why 70% isopropyl often works better than 99%. It’s the minerals in water that make it taboo on electronics (although some older cardboard enclosed stuff hates both) but it’s safe if the minerals are gone. I heat it in a mug in the microwave to high-warmish, and I use a poly bristle small paintbrush to loosen dirt. This works really well when I’m restoring old studio gear. DON’T HEAT YOUR ISOPROPYL!

For the knobs, if you don’t have an ultrasonic cleaner, dishsoap and hot water is awesome. I put the knobs in a net bag and run them through the dishwasher with heated drying turned off. If they are a bit greasy, try soaking them in Simple Green for a few minutes.

Smoke residue gives me a rash, so I wear gloves and a mask when I handle gear before cleaning…

Good luck!



If cleaning the knobs turns out to be too much of a hassle (or if you just can’t get the smoky smell out of that rubber), you could always buy new knobs as a replacement - although you’ll only get the white ones.


Try placing it in a tub/container with some ground coffee in a smaller container beside it, the ground coffee should absorb the smokey odour.

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Decades ago, I worked as a repair tech on Tektronix oscilloscopes. The general procedure for ALL equipment coming from the shop was to put it in the wash rack. The wash rack was a metal box/sink with a lazy susan inside and the exact same kind of sprayer that you typically see in self-serve car washes. We’d take off the side panels and hose the equipment down with soap and water. And then, we’d put it into the dryers, which were enclosed cabinets kept at about 120 degrees. They’d be in there for a couple of days. The only concern with the electronics was there were some large can transformers that could contain a pool of water if they weren’t oriented with the opening face down so they would be sure to drain. We also had compressed air to hit it with before we’d put it in the dryer so we didn’t have to worry about the water leaving spots.

But the bottom line is, you can hose the entire thing off with soapy water, rinse with plain water (or if you’re concerned about waterspots, distilled water), as long as you let it dry thoroughly. Immersing it in soapy water would be fine as well, just make sure you shake it off, and/or blow it off with one of those canned air dusters. In any case, then leave it in a warm spot for a few days to make sure it’s completely dry. Or you can hurry it up a bit by putting it in the oven at a very low temp if your oven will go that low (mine won’t, it’s lowest temp is 325-- you don’t want to use more than about 140 degrees max, and most definitely DON’T use the microwave, that’d burn it out for sure).

Even old equipment that uses paper capacitors can probably be treated this way, as the paper caps are wax dipped. Though that might be the one thing to be a little more cautious about, as I suppose they could store a charge. In all cases, as long as you rinse it well and be sure to let it dry thorougly, the water isn’t going to hurt anything if there’s no power involved. Note, that if the device has a coin battery or other kind of built-in battery, that would be an issue and you’d want to remove it, but I don’t think Clouds has one-- the “memory” it uses to retain settings is a battery-free NOVRAM or similar I think-- and since it’s pretty easy to look “inside” it, you should be able to check to see if you see a small battery or not.

At Tektronix, we never had a failure due to the wash, and never had to repair old dusty, smoky, grimy, greasy, or mouse-infested (yes, that happened), or soda or coffee spilled-on test equipment. And everything was then returned to the customer nice and clean, tested, calibrated and fully operational up to spec.

If all that makes you nervous, then just take the knobs off, take the panel off, then scrub the crap out of them with whatever cleaner you’d like to use, and you’l be fine as long as the smoke hasn’t permeated the electronics so bad that you can smell it even when it’s enclosed in your rack…


That is amazing. Wow.

Incredible! I sort of want to do this now with all the old rack gear I’ve purchased on eBay over the years…thanks for sharing that somewhat counter-intuitive procedure.

Good enough for Tektronix is certainly good enough for me!

Thank you everyone for all your suggestions!

I’ll definitely be implementing some of them going forward.

Again thank you, and all the best!

I second the “wow”. I got a couple of modules that I don’t think were in a smoky environment but they still smell funny and it drives me nuts. Good to know about some of these deep cleaning methods!

Just to make things clearer, are your temperatures in Fahrenheit, Sync?

This reminds me of the video that Kevin Lightner (RIP) posted over a decade ago that made the rounds - him cleaning a filthy Arp Odyssey:

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Yes. The point is just to help the evaporation a little bit, not to bake the thing and you wouldn’t want it to get so hot that it could soften the solder. That’s why it’s best to do it for a while-- if I remember right, we did it for a couple of days, but we had an oven cabinet designed specifically for the purpose. If you’re in a sunny area, leaving it outside in the sun during the day for a couple of days should do it. Or maybe you’ve got something that generates some heat you can put it on top of-- as running your stove for 2 days might not be the best solution. Put it on top of or next to a heater vent where the warm air will hit it and leave it for a few days. It may not need that long, but we were doing it for larger and more complex equipment than a Eurorack module, so it had more nooks and crannies and that was just to be sure. Length of time may differ based on how humid the air is in your area, just use your judgement re: how long it takes to dry it out fully whatever you decide to use. If in doubt, give it more time. Might be hard to do if you’re impatient to use it, but probably best to err on the side of caution.

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