Bugera 333xl Troubleshooting?

[amarshism]

If the problem isn't being replicated at other locations then maybe it's your power browning out? Otherwise I'm thinking a shorted channel switch relay. Does the bugera have external switching jacks for use with third party switching systems?

Either way, lesson learned, and don't skimp on your gear. Especially for live use when it can cause slot of professional embarrassment to yourself and band and possible loss of work.

 

[Omega_Void]

If the problem isn't being replicated at other locations then maybe it's your power browning out?

Yeah. Vinny, have you run any other high-power-consuming gear at that location, and if so had any trouble from it?

Otherwise I'm thinking a shorted channel switch relay.

If it was just a relay the channels would swith but there'd be no unusual sounds. The switch-off type noise the OP refers to indicates an interruption in the hi-voltage also.

 

[guitarguru777]

I talk shit about them because they're one-trick pony amps built from the cheapest components money can buy. I think that they're little more than a massive marketing con aimed at convincing people to waste money on pale imitations of popular brands that are simply NOT road-worthy equipment.

1st off ... you are obviously someone who has never owned ANY of the Bugera products. To call the 333XL a one trick pony proves you are a fucking idiot .... lol

That being said ... I have been gigging mine hard for almost a year 3 to 4 nights a week 4 to 6 hours at a stretch and the ONLY issue I have ever had on the amp is the "OMG THE STANBY LIGHT WONT TURN OFF" deal. I have been too lazy to go in there and fix it.

Other then that with a retube of JJ and =C= power tubes its been as reliable if not more then my 5150, Krank, and my JCM.

So I dunno where you are getting your BS from but since you have never been an owner I would advise you to just shut up about it. 98% of the problems you hear from Bugera owners are do to them not taking care of the amp.

1. Making sure the tubes are seated properly
2. Making sure the bias is set properly
3. Replacing the shit Bigera tubes for quality tubes
3. Wiping the dust from the exterior of the amp daily
4. Wiping the dust from the interior of the grill weekly
5. NOT PUTTING BEER OR OTHER LIQUIDS ON THE AMP AT GIGS
6. Keeping the dust cover on it when not in use.

These are all STANDARD things you should do with ANY tube amp to keep them in tip top shape. The problem is now that a 12 year old can afford a tube amp they have no idea how to maintain them.



As for the OP ... the power issues is something I thought of too. I would recommend finding a power regulator, and seeing if this fixes the issues. If the power in your house is faulty it could cause A LOT MORE DAMAGE!

Tube amps are VERY VERY VERY finicky to the amount of power they get. If its under powered this could be the issue. Get a power conditioner ASAP and see if that fixes the issue.

 

[155]

It is very hard to troubleshoot amps when one is not actually there to poke around the inside. If it only happens when the amp gets hot, it may be something heating up and desoldering itself. This is fairly common, I've seen it happen in a JCM900 slx and some marshall mg stuff. The solution is the add a bit more solder or a heat sink to dissipate that extraneous heat.

If you don't have experience dicking with amps, I would suggest getting someone that knows how. It will most likely be expensive (typically $50-65/hr + $50 flat bench rate at shops).


There is a common issue with these amps involving a molex connector that can't handle the current running through it so it melts, causing intermittent then complete failure. One should remove the molex connector, and solder the wires directly to the pcb. This happened to mine before I bought, so I bought it broken for $200 and spent 20 minutes fixing it and have logged more than about 1500 problem free hours since.

Burned molex connector coming from power transformer to main board

Wires from molex soldered to main board


I have no problem with Bugera's build quality. I am working on amps and other music gear all the time as a side hustle and I was actually surprised for how organized and clean the 333xl was. The most problematic amps I have ever experienced were a Marshall JCM900 SLX and JCM2000 TSL. The 333xl is my primary gigging amplifier. I generally play two shows a week in a cover band for 4-5hrs each show. Then have two 4-5hr band practices a week. That's about 20hrs a week.

I did this exact same thing to a friends thats probably the problem..

 

[Sloan]

HAHA!

I was able to exactly duplicate the results in the video by quickly and gently toggling my 333xl's main power switch, so that's most likely your problem.

The ultra channel light went out and then a bit later the clean channel light came on. Exactly like in your vid.


Check for loose connections on your power switch.

 

[Damage, Inc.]

HAHA!

I was able to exactly duplicate the results in the video by quickly and gently toggling my 333xl's main power switch, so that's most likely your problem.

...so the problem comes down to shoddy workmanship and/or shit parts. I am well aware that this kind of thing can happen to any amp, but Bugera is not a brand known for its long-term reliability. It's like everything Behringer makes...reverse-engineered from a proven design and made as cheaply as possible. You get what you pay for.

 

[Vinny]

Thanks guys. I plugged it into both my furman and monster power conditioners, and same thing happened.

 

[Sloan]

...so the problem comes down to shit happens.

 

[Vinny]

Hahahahahah nice edit Sloan!
I meant to look inside it today, but I've been super busy with recording and other stuff. I'll let you guys know if I find anything suspicious very soon!

 

[Vinny]

Ok, so I took the amp out of the shell and looked around and tugged on every little cord that my little chopsticks would allow me to (nothing too harshly though obviously) and that I felt comfortable with (coz I'm a wimp and don't want to get electrocuted hahaha), and all of the connections seem to be nice and tug.
Molex wasn't burned at all.
BUT I did notice that one of the power tubes made a slightly different tone when gently tapped on than the other power tubes, and isn't lit up as much... Could a single power tube be the problem?

 

[Vinny]

Ok, ALSO I have had it on for over 1 1/2 hours out of the shell and it is still working just fine... So that makes me suspicious of a heating/cooling problem too. But I haven't actually played through it yet.

 

[viralz]

It seems that your amp don't like Creed

 

[Vinny]

Funny, I was thinking the same thing...

 

[Omega_Void]

... I did notice that one of the power tubes made a slightly different tone when gently tapped on than the other power tubes, and isn't lit up as much... Could a single power tube be the problem?

No. It would affect the sound, but not the switching circuitry.

Ok, ALSO I have had it on for over 1 1/2 hours out of the shell and it is still working just fine... So that makes me suspicious of a heating/cooling problem too. But I haven't actually played through it yet.

Does sound like a heat issue inside the amp itself. Sloan has proved experimentally that a temporary interruption in power produces the exact same result.

So there's a problem connection which loses contact when it heats up, and it's between the mains inlet and the power transformer.

If all the solder joints are sound, it might be:

1) an iffy molex connector -- if one contact inside expands enough to lose the mechanical connection, then instead of overheating and burning it would heat up and then lose connection until it cooled off a bit.

2) a similar thing occurring inside the power switch.

3) ????

Since burned molex connectors are known to happen, it would seem prudent in any case to remove it and solder the wires to the PCB like Sloan did, as a safeguard against future failure.

If that doesn't cure the amp, you could try jumpering the connections on the power switch. If the problem goes away when the power switch is bypassed, and comes back when the jumper wire is removed you'll know it's the switch.

 

[Vinny]

...So it just started doing it again when I turned the Stanby on... FML

 

[Sloan]

Did you check connections yet?

 

[Vinny]

Yup. I'm by no means an EE, but everything seemed to be snug.

 

[Sloan]

Have you tried to track the problem starting from the power switch? I would power it up and gently toggle the power switch just to see if you can replicate the problem. hunt down and isolate the issue!

 

[Vinny]

Yea, I can't seem to replicate it that way...

 

[Sloan]

If it's not a loose connection, and it worked with more airflow, i'm thinking it could be something heating up enough to loosen it's solder joint. try running it for a long time with a fan blowing on it. may not help since the part is inside the chassis, but it's worth a try.