Acoustic B100 making a distorted crackling noise

AdamK

AdamK

Jan 24, 2015
449
221
4,551
Virginia
#1
That's the best description I can give. For a while now my amp will occasionally make a distorted/crackling noise on notes that seem to be primarily low ones. Was wondering what might be broken here and if it's fixable. The only thing I have against bringing it to a tech is not being able to see what went wrong and how to fix it. I'm very curious being an aspiring electrical engineer. Not sure if I'm up for the challenge of fixing it unless it's pretty simple.

Thanks
 
#2
A super easy test you could try: is to simply plug a guitar cord in between your effects send & return jacks. If this instantly fixes the problem, you could choose to simply leave a short cord in place, or you could clean the switching contacts in your effects return jack that was causing the problem. (Research the term: "dirty effects-return jack" for more info, you'll discover its a fairly common problem in most all brands of bass amps)
 
#3
anderbass said:
A super easy test you could try: is to simply plug a guitar cord in between your effects send & return jacks. If this instantly fixes the problem, you could choose to simply leave a short cord in place, or you could clean the switching contacts in your effects return jack that was causing the problem. (Research the term: "dirty effects-return jack" for more info, you'll discover its a fairly common problem in most all brands of bass amps)
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Ah of course! I did this earlier but never thought to listen for it. Of course I wouldn't hear it while the effects were active so I'd need to turn them off. Thanks for the advice! It did sound like a fairly common problem.
 
#6
So I just tried it out, going through the pedal and not going through it, and it wasn't making the sound. I'm sure it will happen when I start playing some other time. I'll also make sure to monitor whether or not I have anything else powered on that is in the vicinity in case it's a voltage problem (doubt it).
 
#11
AdamK said:
That's the best description I can give. For a while now my amp will occasionally make a distorted/crackling noise on notes that seem to be primarily low ones. Was wondering what might be broken here and if it's fixable. The only thing I have against bringing it to a tech is not being able to see what went wrong and how to fix it. I'm very curious being an aspiring electrical engineer. Not sure if I'm up for the challenge of fixing it unless it's pretty simple.

Thanks
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anderbass said:
A super easy test you could try: is to simply plug a guitar cord in between your effects send & return jacks. If this instantly fixes the problem, you could choose to simply leave a short cord in place, or you could clean the switching contacts in your effects return jack that was causing the problem. (Research the term: "dirty effects-return jack" for more info, you'll discover its a fairly common problem in most all brands of bass amps)
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Interesting. This has just started happening with our lead guitarists Fender Reverb Twin, though it's happening more on his higher notes, i believe. @anderbass, do you recommend trying this in his case as well?

BassmanPaul said:
Or a Cell phone sitting on top of the amp! :D
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AdamK said:
Is this true??
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BassmanPaul said:
Yes!
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Interesting!
 
#15
I've had a couple of the spade connex at the speaker get too loose and make some serious bad noise. The male is actually a bad fit to the female - which is larger and sloppy.

Replace them with automotive spades (female) in the RED sleeve size. The BLUE ones are also too big.

Standard audio spades don't seem to work - so I go straight to the automotive versions first.

The speaker has to come out after the grill gets removed.....the grill has four Velcro pads at the corners. This too ---- the piping comes with the grill - so don't try to separate them.

I use a cake frosting spatula to get it apart - it's super flexible and very thin and springy.

The speaker is held in place with Phillips head screws and there were compressible composition washers under the screw heads.

On the off-chance that the spades are loose inside the amp/head - you have to pull the head out of the cab. Be careful that you pay attention to the length of the wires from the rear of the amp, that go through the floor of the head compartment, and go to the driver (speaker). It isn't very long - so watch it!
 
#16
At what volume is the amp causing this noise? It is only a 100 watt amp.
 
#18
That's just avoiding the possible truth. The fact that it only happens at higher output doesn't mean it's OK to leave it this way.

Open up and see if there's a problem with the connections or not. If there is a lot resistance because of weak connex, thankfully a solid state amp can intermittantly "see" an open circuit and for quite a long time it won't have any immediate damage.

Just my advice to keep your nether follicles from future immolation.
 
#19
SurferJoe46 said:
That's just avoiding the possible truth. The fact that it only happens at higher output doesn't mean it's OK to leave it this way.

Open up and see if there's a problem with the connections or not. If there is a lot resistance because of weak connex, thankfully a solid state amp can intermittantly "see" an open circuit and for quite a long time it won't have any immediate damage.

Just my advice to keep your nether follicles from future immolation.
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I didn't say it only happened at higher output. Anyway, it hasn't happened in a long time. It could have been the electronics of my Bose speaker sitting on top of it.
 
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