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Discussion Starter · #1 · (Edited)
(FIXED)Problem with my Bugera V5

I'm pretty sure this is just an issue with the tubes, but I'm no expert so I'd like to get some advice. I've had the amp for 2-3 weeks now and ever since I got it there was this glassy rattling noise when I'd play. It wasn't a big deal but as time went on it got worse and now when I hit certain notes it starts this crazy feedback with all sorts of wonderous popping and scratchy noises.

Anyways I made a short video demonstrating the problem but let me know if this is just a simple tube-replacement issue or if I need to have the amp itself fixed. Also, if you have any tube upgrade recommendations I'd love to hear it!


Current stock tubes are an EL84 for the power tube, and a 12AX7A for the preamp.

EDIT 02/03 : EuroTubes tube dampeners fixed everything :D.
 

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While i don't own the amp, that sounds like a faulty preamp tube issue. You may wanna make sure they are in there tight or that the connector pins are tight too.

Since I don't know the amp's "character" and what your looking for out of the amp, It's harder for me to make a recommendation, but the Tungsol reissues are a great tube if the factory one is faulty.
 

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Discussion Starter · #3 · (Edited)
While i don't own the amp, that sounds like a faulty preamp tube issue. You may wanna make sure they are in there tight or that the connector pins are tight too.

Since I don't know the amp's "character" and what your looking for out of the amp, It's harder for me to make a recommendation, but the Tungsol reissues are a great tube if the factory one is faulty.
Thanks for the reply. I got this amp to demo and use a lot of pedals with. It has a pretty decent clean tone but breaks up easily(only 5 watts) but that's what I love about it, stock tubes aren't bad at all. But any kind of tubes that would produce a clearer/brighter tone(without being ice-picky) would be great.

Current tubes are Bugera brand.

EDIT: As long as I replace the preamp tube with some kind of 12ax7 does it matter what the letter is after the 7?
 

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EL84 amps generally like overdriving the power section (running the volume high) which is why it's a 5 watt amp). You may consider switching to a colder EL84 (higher number on the GT scale). It will let you break up later. This will let you run a higher gain 12AX7 (like a TungSol or RFT) in the preamp and it will sound cleaner. Using a 12AT7 in the preamp will lower your preamp gain by about 20%.
 

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That sounds like a bad power tube. I agree with sonic about switching to a colder tube, except that I sounds like you like the early breakup.

can you tell us everything that's printed on each tube??

FWIW: any 12ax7 will work........I prefer the electro-harmonix Russian 12ax7's
 

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Discussion Starter · #6 ·
EL84 amps generally like overdriving the power section (running the volume high) which is why it's a 5 watt amp). You may consider switching to a colder EL84 (higher number on the GT scale). It will let you break up later. This will let you run a higher gain 12AX7 (like a TungSol or RFT) in the preamp and it will sound cleaner. Using a 12AT7 in the preamp will lower your preamp gain by about 20%.
If I used a 12AT7 preamp tube would I need to rebias it or anything?
 

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I'll put a recommendation in for JJ's from Eurotubes being worth a look as well. For 12ax7's I like the Tung Sol's mentioned as well as the EH's but for EL84's, I'm a fan of the JJ's. Let the guys at Eurotubes or Doug's tubes know what you're looking for with break-up (early, late, middle) and they'll be able to get you one that'll give you a bit more clean headroom, a bit less, etc.
 

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Discussion Starter · #10 ·
I ordered JJ's EL84 / 6BQ5 power tube along with a JJ 12AT7 / ECC81 preamp tube.

Any inherant conflicts with this pair? Really been itching to do a series of reviews so I went ahead and ordered. As long as nothing is in danger of exploding id like to try it, then if the tone is meh I could look into some other options. Thanks for pointing me towards euro tubes as well!

Also, when it comes to taking out/replacing the tubes. They feel pretty snug in the amp and I'm worried about applying too much pressure from having to grip the tubes. I'll read up on it before I go yanking and plugging but any tips would be greatly appreciated.

Thanks :).
 

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Shouldn't be a problem. AT tubes can be used in AX sockets and the result will be less gain from the tube and some volume drop. They're often used in these little 5 watt amps because it gives you a bit more head room for cleans. As for the EL84, I think the JJ's are great. I run 4 in my Mesa Rocket 44 and another in my Peavey Mini Colossal. Never had an issue with them and they last a long time.
As for swapping in and out tubes, it really is as easy as changing a light bulb. Make sure that you let the amp cool first (not as important for pre-amp tubes, but you'll burn your hand on the power tubes). Grip at the base and pull straight out. If you need to wiggle them a little, that won't hurt anything, just be patient and work them loose. Before putting in the new tubes, you may want to spray some contact cleaner on the new tubes pins. I do this from time to time but it's not totally necessary more than 1 time every few tube changes. Keep an eye on the pin configuration when you pull the tube out to speed up the process of lining up the pins to the correct holes when putting the new tubes in.
 

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Good choice on JJ's EL84's. It's what I use in my Orange Tiny Terror and i've definitely tried all the other modern tubes (chinese, Sovtek, etc) and the JJ's just have the most excellent musical quality to them in the EL84 tube.
 

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Discussion Starter · #14 ·
Ok folks, still not out of the water. Just put the new tubes in and I'm still getting a really noticeable glassy-rattle even at low volumes.

I can't imagine this is intended, did I just get -another- bad set of tubes?
 

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Did you swap both tubes out at the same time? If so, try putting the old preamp tube back in with the new power tube and vice versa. While it is possible that you got another faulty tube, it's extremely unlikely that all 4 of the tubes in your possession are faulty. Perhaps a certain combination will allow you to weed out the offending tube/situation. See if that makes a difference. If not, more than likely there is something wrong with the amp rather than the tubes. If you have access to other tubes from different amps (provided they're the same type), try switching in a known to be good tube and see what happens.
It could also be an issue where the tube is physically rattling around in there due to close proximity to the speaker in the combo). If that's the case, bugera or an aftermarket company might offer some sort of tube guard that can more securely hold the tubes in place and keep them from rattling.
 

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Discussion Starter · #16 ·
The main offending tube seems to be the El84s, so I think the preamp tubes are fine(though the 12AT7 sounds a lot nicer to my ears :D.)

The new el84 produces the glassy-rattling noise, but the old one produces the feedback/poping/rattle with either of the preamp tubes.

So my luck isn't as bad as I thought it was, I'm gonna head over to the store that shall not be named and see if they have any EL84s. I'll keep looking into tube dampers/guards, but there doesn't seem to be a ton of information on them. You'd think they'd be sold by all the major music retailers.
 

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Discussion Starter · #17 ·
Fixed!

A local shop happened to have an old single EL84 in stock, seems to have solved the issue. I still get some of the glassy-rattling but it's barely noticeable and only happens on higher volume settings(even then it gets buried and only rears its head when the chord/note dies out.)

Still gonna look into those tube dampers, with those I imagine the problem will completely disappear. Thanks all for the advice :).
 

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Discussion Starter · #20 ·
there is something called tube rattle, eurotubes explains this. that may be your problem. combo amps have this
I've played through a lot of tube combos that didn't do this though, or by the time they did the amp was loud enough to completely drown it out and I didn't notice it.

The tube I just stuck in is fine, but I went ahead and ordered some dampening rings.
 
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