Amp crackles/pops

G

greatbob6

New member
So, recently my AC15 has started to making some random crackling/popping sounds when its on, even with the volume all the way down and guitar disconnected. From looking around online a little bit it sounds like it might be a preamp tube that's no good...does that sound like the most likely culprit? I've only had it for about a month and it hasn't left my house since I got it...it definitely has not been treated roughly.

I may have to swing by the shop I bought it at and get it checked out tomorrow...they are closed on Sunday and hard to get to between when I get off work and the time they close during the week.
 
Re: Amp crackles/pops

Probably dirty or moist valve base connections. Where do you store the amplifier?
 
Re: Amp crackles/pops

I use a basement bedroom as my office/music room. I've never had any problems with moisture though. I'll check and make sure all of the tubes are seated properly.
 
Re: Amp crackles/pops

If the problem still persists after making sure they're all in the sockets properly, it is probably a tube issue. Preamp or power amp? Depends.

In my experience with my Crate V32, I tried replacing the preamp tubes first (I didn't really know any better, and thought they were the issue) but the problem persisted. So then I ended up buying a new quad of EL84s for the power section and the problem was gone! Amp had never sounded as good as it did then!

I've got the same issue happening again now and I'm grabbing power tubes first, but as I said, I feel like the issue could come from a few things in the amp (and I'm certainly no expert on them).
 
Re: Amp crackles/pops

The sounds happen even with the volume and master volume turned completely down, so it seems to me that it would most likely be the power tubes. I have an extra 12ax7 so I can easily check the preamp tubes, unfortunately I don't have any El84s lying around. Although, at this point since the amp is so new I may just take it back to the shop where I bought it and have them check it out so they don't think I was screwing with it. :)
 
Re: Amp crackles/pops

greatbob6 said:
The sounds happen even with the volume and master volume turned completely down, so it seems to me that it would most likely be the power tubes. I have an extra 12ax7 so I can easily check the preamp tubes, unfortunately I don't have any El84s lying around. Although, at this point since the amp is so new I may just take it back to the shop where I bought it and have them check it out so they don't think I was screwing with it. :)
Click to expand...

You should DEFINITELY do that, based on principal alone... I had an AC30TB back in 2004 that had a similar problem... Even with guitar unplugged and volume down, it would crackle/pop loud! I had a little experience with electronics back then, and found a 2-watt wire-wound ceramic resistor loose on the power rail...

If it's new enough, return it for certain! Just to be safe and save you cheddar on tubes and other stuff you may not need...
 
Re: Amp crackles/pops

If you would replace the output tubes, and the problem dissappears, it was obvious the problem was due to the power tubes, if it is still there, I would start to think about damaged/cracked screen resistors that cause this problem, in that case, replacing them would bring the solution.
But as said, I'd try switching power tubes first, I know you don't have any lying around, but you'll need spared anyhow, so this may be the time to order a set of EL-84 and give it a try! ;)
 
Re: Amp crackles/pops

I have a "popping" issue when I switch channels on my amp, but it doesn't always happen. Would this be tube-related?
 
Re: Amp crackles/pops

greatbob6 said:
The sounds happen even with the volume and master volume turned completely down, so it seems to me that it would most likely be the power tubes. I have an extra 12ax7 so I can easily check the preamp tubes, unfortunately I don't have any El84s lying around. Although, at this point since the amp is so new I may just take it back to the shop where I bought it and have them check it out so they don't think I was screwing with it. :)
Click to expand...

New enough to be under warranty? Don't touch it inside [ may void warranty ]. Take it back to where you got it.

The crackles and pops could be anything from crappy solder joints , to faulty parts. [ caps resistors ].
 
Last edited:
Re: Amp crackles/pops

GoldenVulture said:
What sort of amp? Does it have any Solid State circuitry?
Click to expand...

It has a solid-state rectifier. It's definitely due for a tube change all around. I've got a set of EH EL34's and I'll do the Tung-Sol in V1, Mullards in the others preamp. If the pop persists then it's something else.
 
You must log in or register to reply here.
Back
Top