What’s that wind in my champ

[Kesi from Hungary]

I have a '74 Fender Champ. Lately I've been suffering from scratchy pots. They have already been cleaned and sprayed, but are still very scratchy so I am going to replace them.

But that's not the problem or my question. I also hear a whispering sound like the wind or sea waves with sometimes a crackle from the volume pot.

Is that windy sound caused by the bad volume pot or is there something else that might maybe a bad capacitor.   

Does anyone recognize this?

[Dave]

I would try a shot of WD-40 in those pots before I sprang for new ones.


Not sure what to tell you about an amp with the winds.


Dave

[JPK]

I'd recommend something made for electrical cleaning like DeoxIT D5. This is what I use. Then you're not leaving behind stuff you don't want in there like silicone, etc. I got this suggestion here from the old timer amp gurus. 

[rafe]

Id check for leaky caps (dcv)

[Dave]

I'd recommend something made for electrical cleaning like DeoxIT D5. This is what I use. Then you're not leaving behind stuff you don't want in there like silicone, etc. I got this suggestion here from the old timer amp gurus. 

WD-40 has no silicon. The reason I use it is that it is a little oily and the oil lubricates the resistive surface and helps sometimes when pots are scratchy and whatnot. Anything that cleans and then evaporates away is good is dirty is the only problem.


Dave

[sluckey]

Usually when someone mentions WD40, they are talking about the original formula that has been around for decades. I would never use that on electronic circuits. But today there is a huge family of WD40 products that cover a lot of lubricant applications. One is even pure silicone spray. Interestingly they even have an electronics cleaner made specifically for the task. And it leaves no residue.

     https://www.amazon.com/WD-40-Specialist-Electrical-Contact-Cleaner/dp/B00AF0OFVU/

[Dave]

I would never use that on electronic circuits.

Boy, I would, and do frequently. It works great. Besides, he says that he is going to replace the pots anyway, so what could it hurt?


Dave

[66Strat]

Use your DVM to check for a leaky capacitor or conductive board.

[Willabe]

I would try a shot of WD-40 in those pots before I sprang for new ones.

WD-40 is not for cleaning pots.

[Willabe]

I also hear a whispering sound like the wind or sea waves with sometimes a crackle from the volume pot.

Carbon comp plate resistors can do that.

[PRR]

Have you changed tubes? "Wind" sounds to me like maybe dirty cathode, replace the tube.

[Kesi from Hungary]

When I completely served the champ earlier this year, the misery started with the scratchy and windy thing after a couple of months. First I cleaned the pots and lubricated them with spray and when that turned out not to be enough, I carefully opened them and cleaned them completely again. That didn't help then. They are still the original ones from '74.

The next action I took was to change the tubes with no results.

[glass54]

WD40 (Water Displacement and Solvent) Does not lubricate!
WD-40 was invented in San Diego in 1953 as a rust-prevention solvent for Atlas missile outer skins.

I would and do use DeoxIT D5. At least it doesn't appear to dissolve any original lubricant left in the pot 
I too would look for Leaky caps and conductive PCB.
Regards
Mirek

[Dave]

"Does not lubricate!"


Hahaha. I'll be damn


Dave

[Kesi from Hungary]

Because I don't have Deoxit 5 (expensive stuff too, by the way, €33 I saw) I did a test with WD-40. A small improvement in reducing cracking and wind, but also a clear improvement in volume.
So I immediately ordered new pots to start with.
Also checked for leaky caps but couldn't find anything. They were also all renewed earlier this year.

[sluckey]

Is this the Fender champ 12 that you were modifying back in the summer of 2022?

[dude]

He said amp has pots dated 1974, couldn't be the Champ 12, wasn't made till early nineties, maybe late eighties..? But if it is, that amp has issues, completely cheaply made for one, PCB board is the worst, although the tubes use wire from the PCB, better than attached to the board .

[Kesi from Hungary]

I got both champs. This one is the silverface from ‘74.

20 years ago when I played a lot in bands they called me the Champ man

[Carlsoti]

Leaky coupling cap or a wonky plate resistor would be my guess, after swapping known-good tubes through each position.

[PRR]

{Original flavor WD40}

Does not lubricate!

It is very high-spec highly specified kerosene, Diesel fuel oil. It is not a good lubricant; OTOH it is better than petrol/gasoline/naphtha/benzine. If it would stay, it would "lubricate" good-enough for doors and pots. Low bearing speed and not-high loading.

In household squeaking, it is "addictive". Use it once and you will 'need it' again and again. Because the stuff evaporates just slow enough that you will use it again instead of getting a low-volatile oil that will stay.

OTOH, gasoline is surely not a lubricant but WWII fighter airplanes doing emergency start in cold weather would dump 50% gasoline in the oil to thin it so they could get to intercept height before the bombers got past them. Not great for engine life or pilot safety but it usually worked.....

[bmccowan]

In 1974 I was working part time in a bike shop. Customers used to come in and argue that WD-40 was a good  lubricant. We would argue that it was a pretty good cleaner and a lousy lubricant. 50 years later people are still arguing.

[Dave]

I don't know what it is, but I have had good luck using it on pots. Been using it for many years. I wonder how many of the folks arguing against it have ever tried it.


Dave

[dude]

PRR, you’re like a dictionary, must be older than l, just kidding. I love reading your posts, filled with good info,Cheers

[sluckey]

In household squeaking, it is "addictive". Use it once and you will 'need it' again and again. Because the stuff evaporates just slow enough that you will use it again instead of getting a low-volatile oil that will stay.

Perfectly stated! Probably 99% of WD40 users fit this scenario. I'm guilty too. Spray that squeaky door hinge. See how quiet it is? Repeat next week.   

But I will never spray it onto an electronic circuit. There's just too many specialized products for that.

[glass54]

+1 with Sluckey

But I will never spray it onto an electronic circuit. There's just too many specialized products for that.

Have you ever noticed the inside of an amp when someone ("amateur technician") has been liberal with WD40 
Pots and chassis have a substantial amount of dust/grit/dirt collected where the the WD40 flow has happened and the smell is quite unpleasant.
....and the amp still has original faults! In the end, it's probably more cost effective and rewarding to replace the pot.
My 2 cents worth

[Dave]

OK... In light of Glass54 getting personal, I'm sorry I suggested he use if a little WD-40.


Dave

[glass54]

Dave, I'm not trying to get personal. It is my opinion that WD40 is EXCELLENT when used for intended purpose.
A new AB or Alpha pot has a nice smooth action (I believe it is a long lasting lubricant) and using WD40 can dissolve this.

When I was young, I too used WD40 in less than suitable applications (ie guilty) but now "the world is our oyster" and we have a fantastic choice of products.
....and we are here to bounce ideas off our colleagues who may have better solutions OR found really good products.

Kind Regards
Mirek

[Dave]

And I was suggesting that rather than replace a pot that was original to the amp, in my experience and sometimes, a shot of WD-40 works to restore the normal operation of the pot. I said it because I have done it and it has worked. I admit that its not a miracle cure, but I have seen it work. At the end of the day, it couldn't hurt.


Dave

[bmccowan]

At the end of the day, it couldn't hurt.

I think the point is; if you are going to shoot something into the pots, use the most appropriate stuff. Caig Deoxit D and F series have stood the test of time. I use D5 and F5 sprays. F5 lubricates better, so I use that on pots. If they prove more stubborn, I use D5 first to bring them back and finish up with a shot of F5.
They work better than WD-40, so why use WD-40?

[ALBATROS1234]

I once had noise similar to that on a Silvertone R2R I converted into a guitar amp. It ended up being a connection on a can cap to a dropping resistor. I reflowed the solder joint and voila. Saying that sometimes a solder connection that looks fine might be a culprit for intermittent noises. Use the chopstick method and do some probing about tapping and give a little shove on solder joints, it you can make the noise happen at will try to reflow the joint.

[Kesi from Hungary]

Fixed  the problem. The wind has died down.

Installed the new alpha pots yesterday and the windy sound was immediately gone. Also an improvement in sound. As if a blanket had been pulled off.

But the scratch was still there. So maybe a leaky cap or a grounding problem, which was previously suggested.
I started searching on this subject and discovered that voltage could be measured on the pots. Especially on the volume pot, there was 30V on the left log.
The culprit was the 250pf treble cap. A silver mica that was probably soldered too hot.

Problem solved. But just have to get used to the trebli sound again.

Thanks everyone for the suggestions and the product knowledge information.

[rafe]

I just went through the same thing with my 60 GA-5  It was a swoosh swoosh sound on the Volume (only) pot and scratchy too ....It was the cap passing DC voltage ......The .02 coming off the plate of first stage.....to the pot Now every thing is ok ...other than early break-up ...which might or may not be adressed....lol

[ALBATROS1234]

It is usually a cap, just saying.