bugera issues...

[Grizzly_Diesel]

i bought a bugera 333xl infinium about three years ago. its worked great since. now it has horrible feedback on the gain channels. the clean channel is poppy? I'm running a boss ns-2 noise suppressor and an mxr berserker overdrive. i put new tubes in it about a year ago. i recently got a new job so i hadn't played it for 4-5 months. its all plugged into one of the live wire power strips that's supposed to provide more protection and hiss reduction. any idea's where a good place to start on finding the issue?

[zzmoore]

Re: bugera issues...

It sounds like an amp problem but.....unplug everything but the amp, then insert the guitar if the amp is fine.

[GilmourD]

Re: bugera issues...

I'd check the preamp tubes first. Take a regular ol' #2 pencil or a chopstick and GENTLY tap on each preamp tube. You'll always hear something with a good tube but you'll know when you tap on a bad tube.

If the preamp tubes are fine then you might have a bad power tube.

Tubes go weird sometimes.

[Chickenwings]

Re: bugera issues...

tubes

start there.

[Grizzly_Diesel]

Re: bugera issues...

OK so i had my computer and TV plugged into the strip as well. i unplugged the tv and computer. now the only thing on the strip is the amp and my interface, monitors and pedal power supply. ran the cable straight from the guitar to the amp and it didn't change anything.the buzz is so bad i cant even get a guitar signal to come through the speakers. tapping on the tubes makes no sound. I don't know if you'd hear anything through the feedback though

[Grenade]

Re: bugera issues...

Don't the infinity series have LED's on the back for tubes?

[GilmourD]

Re: bugera issues...

OK so i had my computer and TV plugged into the strip as well. i unplugged the tv and computer. now the only thing on the strip is the amp and my interface, monitors and pedal power supply. ran the cable straight from the guitar to the amp and it didn't change anything.the buzz is so bad i cant even get a guitar signal to come through the speakers. tapping on the tubes makes no sound. I don't know if you'd hear anything through the feedback though

What's sitting next to the amp and are any of your power plugs missing ground pins or have the ground otherwise defeated?

[Fred2202]

Re: bugera issues...

Sounds like you might have a bad jack at the guitar input. Solder joint that grounds the jack might be cracked or broken. A lot of amps have the input jack soldered directly to a circuit board and sooner or later the solder joints Crack and fail. If not one of the preamp tubes is really shot. Does the volume of the noise get louder or quieter when you turn the volume up or down?

[Darg1911]

Re: bugera issues...

Sounds like you might have a bad jack at the guitar input. Solder joint that grounds the jack might be cracked or broken. A lot of amps have the input jack soldered directly to a circuit board and sooner or later the solder joints Crack and fail. If not one of the preamp tubes is really shot. Does the volume of the noise get louder or quieter when you turn the volume up or down?

Along these lines, make sure the cable or guitar isn't the problem. Plug straight into amp. Try different cable and/or different guitar or plug into a different amp. Just rule the simple stuff out.

[Grizzly_Diesel]

Re: bugera issues...

ive tried three different guitars and no change. all plugs have grounds intact. and right next to the amp is my monitors and interface. nothing changed over the course of the 4-5 months that it sat. and it does have the leds on the back for the power tubes, but not for the preamps.

[Darg1911]

Re: bugera issues...

ive tried three different guitars and no change. all plugs have grounds intact. and right next to the amp is my monitors and interface. nothing changed over the course of the 4-5 months that it sat. and it does have the leds on the back for the power tubes, but not for the preamps.

OK, so you've eliminated the guitar as the problem. Got another amp? Does it work fine with your cable? If no other amp, do you have a spare cable to plug in? It's probably not the cable, but you have to eliminate it or risk chasing your tail. After that, do you have any spare 12ax7 tubes? Even if you only have one known good spare you can start swapping preamp tubes, one at a time to at least narrow it down to being tube related, and probably rule it in or out. If it is a preamp tube gone south, it's probably only one unless there is another problem with the amp that took out the tubes. The infinium tech. with the LED's for the power tubes is pretty cool, but I'm not so sure how much I would trust it to completely tell me the power tubes were ok. Still, I'd start with the preamp tubes.

One other thing. A microphonic tube isn't necessarily a "bad tube". It is a noisy tube. It may or may not cause problems. So just because you tap a tube and hear the microphonic "ring" through the speakers, doesn't mean it's the cause of all the feedback that you report is making your amp unusable.

[Grizzly_Diesel]

Re: bugera issues...

well moved the amp and plugged the strip into another outlet and the buzz went away. i added my noise supressor and it was still good. then i added my od and the horrid fuzz came back. so i think it was a combination of a faulty outlet and my od pedal died. thanks for all the advice!