Cab crackling

[Wylie]

I wonder if you guys can help me. When I plugged in today to practice, and played at about medium-loud volume, I noticed a crackling from the speaker. Definitely not a vibrating speaker or loose screw, but a crackling; not loud but noticeable. With more intense mid-range notes, the crackling increased, and also increased with higher volume settings.

I switched out my instrument cable, also made sure the jack/input on the bass was tight. I even plugged the amp into a different wall outlet -- trying anything. Got the same result.

I haven't even gigged recently, haven't moved the amp and cab in weeks. There's nothing I can see that would cause this to happen. BUT ... I also noticed that my tone control, which I keep rolled all the way off (down), seems to be extremely sensitive; when the knob is turned, it makes a fair sharp bit of crackling.

Are these things related? I'd appreciate any help.

Thanks.

Ted

[TheButler]

I had this very same problem with my Mesa Boogie 1516 cab. Unfortunately, I only noticed after I loaded it into the car (in its flightcase), knackered my back and took it to a fellow basschatter for a trade negotiation (that we were both very much excited about). Last time I properly used the cab there was no crackle but upon plugging it in to test it, before the trade, it started to crackle. I opened the back, check the connectors and stuff, and look for any physical damage on the drivers, but this was probably futile, given its probably something I won't be seeing thats bust. So... i'd also appreciate help!

A crackly pot is probably not related...

[Mr. Foxen]

Possibly a bad connection somewhere, pull off an put back on spade connectors, resolder everything.

[JTUK]

[size=6][b][sup]Have you ruled out the amp being at fault....sounds like a possible dry solder joint somewhere in the chain.?[/sup][/b][/size]
[size=6][b][sup]I'd isolate the amp and cab and see which one keeps showing the crackling and then you'll know which to concentrate on[/sup][/b][/size]

[Wylie]

Thanks for suggestions, Jtuk, Butler, and Mr. F., I will take a look inside and see if I can detect anything loose.

tg

[TheG]

Hi there this sounds like the tone control could be dirty I have just experienced it on an amp I haven't used for a while. I think the dirt settles in or something so is worse when you leave it for a while.

The first thing to try is moving the tone control all the way forward and backwards several times to clean the dirt away inside the pot. It may be crackly as you turn the knob so keep turning it back and forth until the crackling stops. Then see what it sounds like then. If its really loud do it with the amp turned down and then have a listen again.

The correct thing to do would be to get some "contact cleaner" for cleaning pots and switches from Maplins or somewhere and spray it on the tone control and then turn it forwards and backwards again to give it a clean. It might be expensive though cant remember?

Maybe a good idea to clean all the rest of the knobs as well in the same way.

Let me know how you get on and if that actually solves anything or not.

[TheG]

Or try the cab through a different amp / amp through different cab if you can to eliminate the crackly pot thing.

[TheButler]

I tried the cab through my amp, but given my amp has a crackle it didn't narrow it down. I think i'll do as Mr. Foxen suggests and get replacing connectors. all the drivers are making noise, and there isn't any overt signs that something properly busted (unless a slight crackle constitutes something serious? )

[Wylie]

[quote name='TheG' timestamp='1333919823' post='1608342']
Hi there this sounds like the tone control could be dirty I have just experienced it on an amp I haven't used for a while. I think the dirt settles in or something so is worse when you leave it for a while.

The first thing to try is moving the tone control all the way forward and backwards several times to clean the dirt away inside the pot. It may be crackly as you turn the knob so keep turning it back and forth until the crackling stops. Then see what it sounds like then. If its really loud do it with the amp turned down and then have a listen again.

The correct thing to do would be to get some "contact cleaner" for cleaning pots and switches from Maplins or somewhere and spray it on the tone control and then turn it forwards and backwards again to give it a clean. It might be expensive though cant remember?

Maybe a good idea to clean all the rest of the knobs as well in the same way.

Let me know how you get on and if that actually solves anything or not.
[/quote]

Thanks, G., I'll try this. I wondered if it could be a pot (and hoped it was that simple).

tg

[Phil Starr]

By and large broken speakers buzz and broken amps crackle, Intermittent faults are often the hardest to find and by sod's law the most common. A crackle can be anything electrical from the mains socket to the smallest component in the amp. Having said that the 'sensitive' tone control has something going wrong so that is prime suspect. The trouble is that the bit that is causing problems is most likely to be the connection between the slider and the carbon track deep inside the pot and you need to get the switch cleaner inside the works to do anything. Modern pots often have few holes to stop dust getting in and causing this problem which makes them difficult to clean. Spraying the outside or just pulling a knob off (ooh-er) won't do any good and you'll need to take the amp out of it's case at least, be aware of the risk of electric shocks here.

Another useful trick is to get hold of a can of freezer spray. If you spray one component at a time the freezing and shrinking will either remove the fault or make it dramatically worse and you have your culprit.You might find this helpful [url="http://www.ultimate-guitar.com/columns/gear_maintenance/a_guide_to_fixing_intermittent_faults.html"]http://www.ultimate-guitar.com/columns/gear_maintenance/a_guide_to_fixing_intermittent_faults.html[/url] good luck.

[TheG]

Yes intermittent faults are a nightmare. I had an amp that cut out without warning every 2 or 3 gigs and I couldn't predict when it would happen at all. Eventually after taking out 2 amps for every gig and then buying a new amp I rendered it useless as I couldn't even make the fault appear myself at will.

Then a guitarist friend of mine on a gig said I know someone who can fix that for you. I said how can he I cant even get the fault to appear myself. Anyway he was very confident and I just gave in and gave him the amp to send off - the guy was obviously a fool!

3 days later he contacted me "its fixed!" he said. In amazement I went to pick it up.

In the end it turned out to be a cracked printed circuit board that was breaking a contact every so often. Great stuff! I then started using it and it has been fine ever since and that was 5 or 6 years ago.

[Wylie]

[quote name='Phil Starr' timestamp='1333955723' post='1608581']
By and large broken speakers buzz and broken amps crackle, Intermittent faults are often the hardest to find and by sod's law the most common. A crackle can be anything electrical from the mains socket to the smallest component in the amp. Having said that the 'sensitive' tone control has something going wrong so that is prime suspect. The trouble is that the bit that is causing problems is most likely to be the connection between the slider and the carbon track deep inside the pot and you need to get the switch cleaner inside the works to do anything. Modern pots often have few holes to stop dust getting in and causing this problem which makes them difficult to clean. Spraying the outside or just pulling a knob off (ooh-er) won't do any good and you'll need to take the amp out of it's case at least, be aware of the risk of electric shocks here.

Another useful trick is to get hold of a can of freezer spray. If you spray one component at a time the freezing and shrinking will either remove the fault or make it dramatically worse and you have your culprit.You might find this helpful [url="http://www.ultimate-guitar.com/columns/gear_maintenance/a_guide_to_fixing_intermittent_faults.html"]http://www.ultimate-...ent_faults.html[/url] good luck.
[/quote]

Thanks, Phil.

tg