Cutting out?

[ibanezjunkie]

on my valvestate head, which is about 18 years old now according to its serial number, has started to crackle and cut out when you adjust the gain, volume etc.

sometimes it cuts out for about 10-20 seconds before jacking back in. i asked my uncle who is an retired electrician/contractor and he thinks the pots need cleaning.

1. do you think he is right
2. if he is right, what do i clean them with??

thanks

[oldguy]

I think he's right. Electrical contact cleaner.

[ibanezjunkie]

i guess that would involve dismantling the head and cleaning the soldered tabs on the pots?

[oldguy]

No, you remove the knobs, spray a dab back along the shaft so it gets into the wiper, and rotate the shafts to and fro to get the cleaner to work its mojo. Not difficult at all.

[ibanezjunkie]

do you remove the anchoring bolt behind the knob?

[jim p]

I like to use WD40 it is a silicone biased lubricant so it leaves some lubrication behind when you are done. The contact cleaners sometimes just evaporate and in a little while and things go bad again. I used the stuff in the high voltage section of a colour TV and it kept things working for a year then you just sprayed it again. Also works on old spark plug wires when there insulation breaks down. Probably would work well on Lucas ignition system on a damp day. I would see if you can spray into the opening at the back of the pot near the terminals then turn the pot clockwise and anticlockwise a few times to work it in.

By the way WD40 is the #1 product in customer satisfaction.

[ibanezjunkie]

I like to use WD40 it is a silicone biased lubricant so it leaves some lubrication behind when you are done. The contact cleaners sometimes just evaporate and in a little while and things go bad again. I used the stuff in the high voltage section of a colour TV and it kept things working for a year then you just sprayed it again. Also works on old spark plug wires when there insulation breaks down. Probably would work well on Lucas ignition system on a damp day. I would see if you can spray into the opening at the back of the pot near the terminals then turn the pot clockwise and anticlockwise a few times to work it in.

By the way WD40 is the #1 product in customer satisfaction.

i WD40 alot myself :D

being an engineering and technology student, its almost impossible to not use it =]

ill probably clean the pots tomorrow. sundays are usually the days i dismantle everything and clean it etc. it really is unbelievable how much dust builds up on the spiderweb design on my ibanez.

[ibanezjunkie]

just spent about an hour cleaning all the pots out with WD40. Systematically going back over everyone then testing them. It still crackles a tiny bit on the Normal channel Gain, and the master volume, but the important thing is IT DOESNT LOSE VOLUME :D

its good enough to be used for gigs now, as a temporary gigging amp until i get something new with enough kick in it.

[Spudman]

i WD40 alot myself :D

being an engineering and technology student, its almost impossible to not use it =]


I'm sure this will turn into a good lesson for you but NEVER clean pots with WD40. It is the wrong stuff. Deoxit is widely accepted. As a student of technology you should have known that WD40 is not for cleaning electronics in guitars and amps.

[WackyT]

Gotta agree with Spud. DeoxIT (http://www.deoxit.com/) is the stuff to use in this situation. Have had potentiometers destroyed with WD40.

[jim p]

Well I have used WD 40 many times and I am an electrical engineer but whatever?

[ibanezjunkie]

i use it all the time. i clean my PCBs and variable resistors with it regularly :S

[ZMAN]

You guys have some bad information. I agree with Spudman. The last thing you want in a pot is oil. The problem with the scratchiness is dirt and the oil will only make it worse. I would give it a good cleaning with contact cleaner and save the wd for lubrication.

[mrmudcat]

Agreed,we never wd our skate bearings(skateboading ):poke: because it just collects more dirt causing more friction .etc.etc............

[ibanezjunkie]

Agreed,we never wd our skate bearings(skateboading ):poke: because it just collects more dirt causing more friction .etc.etc............

haha i tried that...caused a broken arm going down a hill...then jammed up.

[ZMAN]

I used to cringe at paying 5 bucks a bearing x2 for each wheel for German bearings for my son's boards. But they were sealed and never had a problem. It was worse keeping him in shoes though.

[jim p]

I mulled this over and was just going to let the subject die but.

Just want to go over the subject of pots and cleaning pots. First let’s think of what the construction of a potentiometer is you have a semi circular strip of deposited carbon on a substrate or cermet (a plastic and carbon element) and last the wire wound element with this you have a wiper that is dragged across to produce your variable resistance. So you have the friction of the wiper working against the resistive element and even if you do not turn the pot much vibration will be working the wiper into the resistive element so time is working against the life of your pot. Then dirt and corrosion if this pot is in something you own you should have a good idea if it was driven hard and put away wet, say it is in an amp that has always been indoors and if a tube amp it is nice and toasty most of the time then corrosion is probably not what is happening here. Next dirt the amplifier chassis is an enclosed space and if there is no fan blowing air around then dirt from outside is probably not the cause of our ills. Now if this is something you bought in a garage sale that was in grandpa’s basement or out in the garage for who knows how long all bets are off. So the little guy is more than likely flaking out due to that point contact of the wiper scraping away at it.
So now cleaning a pot cleaning is a bit like using a quart of magic mystery oil in your car to fix the woes of your engine in the back of your head you know this is a Band-Aid and you just may need to replace something if not great. Now I have used contact cleaner on a pot and was not thrilled with the results I got little improvement and it was binding more then before. Probably due to the fact that the major ingredient in contact cleaner is isopropyl alcohol (the pure stuff not watered down) that is a great degreaser and drying agent so now the guts of the pot are bone dry just like your skin if you get some of this stuff on you. So that led me to using WD40 the pot moved freely worked ok and now there is some lubrication to protect from friction and corrosion so that is what I like to use.
Anyway this is all antidotal because I don’t think anyone of us has disassembled a group of equally bad pots tried various methods to clean them and verified the results. So the choice is yours in which way you go.

Now on to the best floor wax to use on your fingerboard.

Oh on the insides of your basic pot on the web there is “The secret life of pots” with a picture of one opened up, in it you can see some nice nicks and wear spots on the resistive element.

[Spudman]

Anyway this is all antidotal because I don’t think anyone of us has disassembled a group of equally bad pots tried various methods to clean them and verified the results. So the choice is yours in which way you go.


We might not have but many other people have done it and they wont suggest using WD40. There is a reason that they make electronics cleaners otherwise we would all be using WD40.

If you have questions on what to use to clean electronic potentiometers then I suggest going to amp builder web sites, guitar builder web sites and general electronic repair web sites and pose the same question to them.

If you ever shot WD40 into a Neve or Allen & Heath recording console you'd be killed on the spot for that.

[mrmudcat]

Last and final comment from me !!


Zero Residue Contact cleaner!!!!!!! Period no ifs and butts:bootyshake:

No WD-40, no De-Oxit, no carb cleaner...

jim p good post.If not copy and pasted from the intraweb then great post!

"semi circular strip of deposited carbon on a substrate or cermet"

This can be effected causing failures do to long enough contact with wd40 etc etc .

Remember the stuff was made to wick away moisture not as a cleaner or lubricant.


Last reply im out!!!!:AOK:

[Rocket]

No WD-40, no De-Oxit, no carb cleaner...
Freon PCA 113.

[mrmudcat]

You can also pull the knobs and shoot some compressed air in the crooks and crannies to clean them before adding anything:AOK:

[Rocket]

Remove all pots & bypass wiring for max... ends cleaning chore!

[jim p]

Well this whole how best to clean a pot thing has been interesting. In surfing around have found that in the antique radio, stereo and camera repair camp they would dissemble the pot gently clean with a plastic eraser then use Teflon grease on the wiper. If the wiper binds then the operation of the pot will not be smooth and may cause audible pops in the output signal. For those of you who talked about slide pots they are a little of a different case (more open greater chance of dirt, dust, Pepsi getting in) but there is slide lube made for that so lubrication would and is used on the resistive element.
On manufacture a different grease or lubricant could be used at different locations within the pot. At the control shaft, the shaft and the front face of the pot makes up a sleeve bearing so a high viscosity grease would keep this from binding and act as a seal to prevent dirt from getting into the pot. Then there is the wiper to resistive element and wiper to commutator ring from what the repair guys have done above nonconductive grease here would work well to prevent binding and with the wiper inside of this dab of grease dirt would just stick to the outer layer and not effect operation.
If in manufacture they did use grease at the shaft blasting cleaner in at the shaft is not a good idea it will move the grease into the body of the pot so working from the back of the pot would be better plus this will leave you with bare metal against bare metal.

For those of you into DeoxIT here is there answer when asked

We do repairs on radio communications and audio/video equipment. Looking for a recommended product for safely cleaning and lubricating modern carbon potentiometers. Our stash Whisk, a good but banned older spray is finally depleted.

Thank you.



Morning,
If the pots are truely carbon contacts then we would recommend the DeoxIT FaderLube. If they are/could be carbon wipers with metal contacts, then we would recomment the DeoxIT D100S-2 product.


If you do not know, I would use the FaderLube first. If that solves the issue than you are good-to-go. If their is meatl on the pot, then the FaderLube will not dissolve oxidation and your issue may still remain. Then use the DeoxIT D100S.

So what is the secret ingredient lubricant in FaderLube and is it that much different then WD 40? For all you know it could be WD 40 but who knows it is a secret.

Now the old repair guys would do a three part process (denial, acceptance, then replacement) if not disassembled then cleaning, followed by drying with hot air gun and last light lubrication.

And some of the old guys would use a light application of WD 40. And some hate it and some used another manufactures equivalent in some cases.

Bottom line do what you feel makes the most amount of sense for you
So "Be the pot" "Wax on, Wax off"