So my amp is acting up. Is it the phase inverter? I dunno...

Agileguy_101

Master of his Domain
My amp has been making a noise for the last few days. It was a crackling sound, like one or both of the speakers were malfunctioning. Didn't make sense as they are both pretty new speakers, but I thought it still might be the source of the problem. I decided to check the tubes to rule that out. I started with the PI for whatever reason, and lo and behold the crackling was gone! However, my amp was making a very odd noise about every 10.5 seconds. I recorded it on the sound below.

Does these sound like symptoms of a bad PI tube? If not, what would you think?

 
Re: So my amp is acting up. Is it the phase inverter? I dunno...

I gotta say... honestly, forums are not the best place to diagnose electronic problems. Not weird problems anyway.

I do hope though, maybe someone here has experience with this strange noise thing.

And no I don't think it's a tube issue. Probably a bad cap. (but I am just some jack on a forum)
 
Re: So my amp is acting up. Is it the phase inverter? I dunno...

Doesn't sound like a tube problem.

What amp is it? Does it have any built-in effects (such as delay)? Does it make that noise with nothing plugged into the amp...no guitar or stomps?
 
Re: So my amp is acting up. Is it the phase inverter? I dunno...

68 Bassman. My cell phone was a few feet from the amp when it happened. Didn't think about that, good idea.

Good news is that I was playing it last night and the weird noise above was gone, but the crackling was back. You can hear it at the beginning of this clip:

 
Re: So my amp is acting up. Is it the phase inverter? I dunno...

68 Bassman. My cell phone was a few feet from the amp when it happened. Didn't think about that, good idea.

Good news is that I was playing it last night and the weird noise above was gone, but the crackling was back. You can hear it at the beginning of this clip:


Yeah, me an my bass player were both getting weird noises somewhat like that through our amps for awhile...When we decided to make a "No phones at practice" rule, it stopped happening. We just leave them in a different room, hasn't happened at all in the three months since the no phones rule.

The crackling though...Does it only happen when you're playing (like in the clip)? Or does it also happen when you're not playing? What about with nothing plugged into the amp? Have ya ruled out faulty cables? Or a corroded jack? Any of the knobs crackle when you move them? Also which channel are you using on the bassman? And do you have all the knobs on the other channel turned to zero (surprisingly does make a difference)?

I got a similar crackling on my SF bassman, turned out the tube for the bass channel (V1) was dieing...Still crackled even though I never used that channel. Replacing the tube cured the problem.
 
Re: So my amp is acting up. Is it the phase inverter? I dunno...

I got a similar crackling on my SF bassman, turned out the tube for the bass channel (V1) was dieing...Still crackled even though I never used that channel. Replacing the tube cured the problem.

Interdasting. The noise is no longer as of today, but I'm going to get a couple of new tubes for my baby just to be on the safe side.
 
Re: So my amp is acting up. Is it the phase inverter? I dunno...

Hey -
If tubes do not fix it...bring it by and pick up a loaner.
Chip
 
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Re: So my amp is acting up. Is it the phase inverter? I dunno...

It sounds like a bad capacitor, when it's an intermittent clicking. It's slowly charging and discharging instead of doing what it's supposed to. That's if tubes and bad electricity are ruled out.
 
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