Dont think i can ever trust a GK head again.

[agedhorse]

Rusty knobs? Since there isn't anything inside a pot that can rust, this is an interesting concept. Care to suggest what is rusting?

 

[Crystalman85]

Rusty knobs? Since there isn't anything inside a pot that can rust, this is an interesting concept. Care to suggest what is rusting?

Well, there was a time when my gk 700rb-II had scratchy knob and the sound kept cutting out. so I had my dad take a look at it(since he has experience in electronic devices) and noticed there was rust or gunk building up on the knobs. I'm not quite sure how this happened, but my dad was able to fix that trouble with contact spray. what he did is that he removed the module part where you dial in the eq and used contact spray and the rust or gunk came off. after letting it dry from the spray, he put the module part back in the amp and it was working like brand new. I'm not quite sure if this was caused by the amp not being covered, but I do know from that moment that this trouble can be fixed by contact spray.

 

[agedhorse]

Contact cleaner will only work if the cause is contamination on the element. Use the wrong material and you are likely to ruin a set of pots.

It couldn't possibly be rust, there's nothing that can rust. This whole thing is pretty weird.

 

[Al Kraft]

I wonder if oxidation on the resistance pad or wiper wear particles were being mis-characterized as "rust".

 

[agedhorse]

I wonder if oxidation on the resistance pad or wiper wear particles were being mis-characterized as "rust".

If there was enough wear to create visible debris, the pot would be well worn out and then some. Same for oxidation, the thickness of such layers are only angstroms thick.

 

[Crystalman85]

Contact cleaner will only work if the cause is contamination on the element. Use the wrong material and you are likely to ruin a set of pots.

It couldn't possibly be rust, there's nothing that can rust. This whole thing is pretty weird.

Well there was some kind of gunk on the knobs. and the contact spray actually did work. and after that, the gk amp has been working good.

 

[JRA]

any brand can produce lemons. and some folks have bad luck. karma brings the two together.

 

[BadExample]

Well there was some kind of gunk on the knobs. and the contact spray actually did work. and after that, the gk amp has been working good.

You have to keep in mind the act of disassembly and reassembly may have cleared off a failed contact somewhere, like a connector contact. Isolating the problem is preferred, because it can be identified and corrected with confidence. That being said, I certainly understand why someone might try to correct the obvious or easy to resolve possible causes before running off to the tech. Hopefully these type of attempts don't cause further problems if the amp does end up on a tech's bench. From the tech's perspective, the worst thing to have on the bench is an intermittent problem. You can't test reliability into a repair.

I'm glad your father's fix has been reliable for you and the amp lives on.

 

[jim nolte]

Contact cleaner will only work if the cause is contamination on the element. Use the wrong material and you are likely to ruin a set of pots.

It couldn't possibly be rust, there's nothing that can rust. This whole thing is pretty weird.

I've got a original '65 Jazz Bass with scratchy pots, I just paid 25 bucks for a small bottle of De-Oxit, you now have me worried about using it

 

[agedhorse]

I've got a original '65 Jazz Bass with scratchy pots, I just paid 25 bucks for a small bottle of De-Oxit, you now have me worried about using it

Is it D-5 spray?

 

[jim nolte]

Is it D-5 spray?

I don't know, it was recommended to me and I'm not home to check. I don't think it's a spray but a drop applicator but I haven't opened the package yet and I can return it. Which one should I be getting?

 

[alaskaleftybass]

@agedhorse can steer you the right direction.

 

[agedhorse]

The spray is far easier to use, just a tiny amount in the slot that the terminals exit from is all that's needed then rotate the control a few times.

This is also called D5

 

[Crystalman85]

You have to keep in mind the act of disassembly and reassembly may have cleared off a failed contact somewhere, like a connector contact. Isolating the problem is preferred, because it can be identified and corrected with confidence. That being said, I certainly understand why someone might try to correct the obvious or easy to resolve possible causes before running off to the tech. Hopefully these type of attempts don't cause further problems if the amp does end up on a tech's bench. From the tech's perspective, the worst thing to have on the bench is an intermittent problem. You can't test reliability into a repair.

I'm glad your father's fix has been reliable for you and the amp lives on.

I don't have any experience with electronics, but the gunk was gone after my dad sprayed the module part with contact spray and the gk amp I've had has been working well since then.

 

[popcat]

Some manufacturers use sealed pots (usually full plastic enclosures which are PC-mount), but many of the panel-mount type are still the open style with a typical aluminum body. Dust can penetrate through the opening near the lugs and sufficient build-up will interfere with the wiper action and cause scratchiness or other problems; such gunk build-up can be cleaned. Auto parts stores carry spray electrical cleaner, and electronic stores used to carry similar called "tuner" cleaner for TV set tuner mechanisms and pots.

I have found that spray Brake Cleaner is less expensive and just as effective, it has a high vapor pressure so it dissipates quickly without any residue (which is why it used on brakes). I usually have some around anyways for cleaning other things (not just brake hardware).

Never use WD-40 on electronics components (or on anything in my opinion), once the carrier evaporates it leaves a coating that is a gunk magnet. For most mechanical apparatus such as hinges or locks, NOT electronics, the silicone sprays perform much better than WD-40 in this aspect.

Also, pot bodies made from steel and not from aluminum can rust (aluminum does corrode to a certain extent), and the better steel pots would have a protective lacquer coating for prevention.

 

[arbiterusa]

I love the OP on this thread: "GK sux. I bought one and it broke, so I bought another one and eventually that broke too, and so I bought a third one. I dunno. I guess I just like spending lots of money on things that break and that I think are crap."

I own GK (two MB500s, now) because they've never blown up on me.
Same with SWR. I've had that Studio head for 28 years now. Bulletproof.
I don't own Ampeg because my old V4B died in the middle of a gig. Right in the dumpster with that one.
Old Fender tube amps have gone bad on me at a rate I find unbelievable.

I don't buy stuff that dies on me. One and done is the rule.

 

[agedhorse]

Some manufacturers use sealed pots (usually full plastic enclosures which are PC-mount), but many of the panel-mount type are still the open style with a typical aluminum body. Dust can penetrate through the opening near the lugs and sufficient build-up will interfere with the wiper action and cause scratchiness or other problems; such gunk build-up can be cleaned. Auto parts stores carry spray electrical cleaner, and electronic stores used to carry similar called "tuner" cleaner for TV set tuner mechanisms and pots.

I have found that spray Brake Cleaner is less expensive and just as effective, it has a high vapor pressure so it dissipates quickly without any residue (which is why it used on brakes). I usually have some around anyways for cleaning other things (not just brake hardware).

Never use WD-40 on electronics components (or on anything in my opinion), once the carrier evaporates it leaves a coating that is a gunk magnet. For most mechanical apparatus such as hinges or locks, NOT electronics, the silicone sprays perform much better than WD-40 in this aspect.

Also, pot bodies made from steel and not from aluminum can rust (aluminum does corrode to a certain extent), and the better steel pots would have a protective lacquer coating for prevention.

Sorry, but NEVER use any of these materials on pots. It's a quick way to ruin a pot. While they may work on SOME pots there are so many incompatibilities between the lubricants and damping compounds that there's no way to know without extensive testing. This is especially true of brake cleaner, which is destructive to most plastics and coatings. Tuner cleaner and contact is similar but less aggressive, still it will dissolve lubricants and allow them to migrate to where they are not compatible with the surfaces.

The only material that I would ever consider for a pot, and only in tiny quantities, is Caig DeOxit (D5 or 5% spray). IME, this is the most compatible material I have seen but overdone can cause problems as well.

 

[agedhorse]

Some manufacturers use sealed pots (usually full plastic enclosures which are PC-mount), but many of the panel-mount type are still the open style with a typical aluminum body. Dust can penetrate through the opening near the lugs and sufficient build-up will interfere with the wiper action and cause scratchiness or other problems; such gunk build-up can be cleaned. Auto parts stores carry spray electrical cleaner, and electronic stores used to carry similar called "tuner" cleaner for TV set tuner mechanisms and pots.

I have found that spray Brake Cleaner is less expensive and just as effective, it has a high vapor pressure so it dissipates quickly without any residue (which is why it used on brakes). I usually have some around anyways for cleaning other things (not just brake hardware).

Never use WD-40 on electronics components (or on anything in my opinion), once the carrier evaporates it leaves a coating that is a gunk magnet. For most mechanical apparatus such as hinges or locks, NOT electronics, the silicone sprays perform much better than WD-40 in this aspect.

Also, pot bodies made from steel and not from aluminum can rust (aluminum does corrode to a certain extent), and the better steel pots would have a protective lacquer coating for prevention.

Sorry, but NEVER use any of these materials on pots. It's a quick way to ruin a pot. While they may work on SOME pots there are so many incompatibilities between the lubricants and damping compounds that there's no way to know without extensive testing. This is especially true of brake cleaner, which is destructive to most plastics and coatings. Tuner cleaner and contact is similar but less aggressive, still it will dissolve lubricants and allow them to migrate to where they are not compatible with the surfaces.

The only material that I would ever consider for a pot, and only in tiny quantities, is Caig DeOxit (D5 or 5% spray). IME, this is the most compatible material I have seen but overdone can cause problems as well.

 

[Red Planet]

I've got a original '65 Jazz Bass with scratchy pots, I just paid 25 bucks for a small bottle of De-Oxit, you now have me worried about using it

Did you get lubricated cleaner or non-lubricated? In potentiometers you must use lubricated cleaner, if you use non lubricated cleaner you will destroy the pot

 

[Red Planet]

News alert for those that don't know any better don't ever use brake cleaner on a guitar or bass amp back away from the brake cleaner.