#1
Hey guys what's goin on? Im sitting here pretty angry right now. I just purcahsed a brand new b-52 2-12 combo about three weeks ago. I got it at GC and got a warranty on it but either way im still mad. I was playing guitar last night for a couple hours, turned everything off, ate dinner, did some homework, and then I went to turn it back on and I get LITTLE sound. The clean channel works perfect. But when I switch it to any Gain Channel i get barely any sound.

I have to turn the amp up to like 6 to even hear myself play on the Gain channel. It is extremely thin and sounds nothing like it should. This is my first tube amp, I love it but not if it keeps this **** up. Maybe I did something wrong. I let it warm up for atleast 30sec before I turn it off of standby. Any thoughts? Will GC cover this since it's practically brand new.
#2
Lol I JUST made a thread about this... I think it might be just a loose tube...

Thats my idea at least, wait till more experienced people comment on this.

Also, they'd cover this. So don't worry about that. You'll get your sweet b52 tone back in no time.
Pain is an illusion.
Schecter Hellraiser C-1 w/ Seymour Duncan JB/Jazz Combo
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#3
Only 30 seconds?
You're meant to give it a good 2-3 minutes to warm up
ohai little sig.
#4
You let it warm up fine. When you turn on amp, do the tubes glow? Is there some black stuff at the top/bottom of any tubes like there was like a mini explosion?
#5
Quote by sesstreets
Lol I JUST made a thread about this... I think it might be just a loose tube...

Thats my idea at least, wait till more experienced people comment on this.

Also, they'd cover this. So don't worry about that. You'll get your sweet b52 tone back in no time.



Doesn't make sense that a tube could come loose from the amp just sitting on my floor.
#6
Quote by jarudy
You let it warm up fine. When you turn on amp, do the tubes glow? Is there some black stuff at the top/bottom of any tubes like there was like a mini explosion?



Ill check when I get home. Im at work right now. I guess that's an easy way to check huh?
#7
Quote by Demonikk
Only 30 seconds?
You're meant to give it a good 2-3 minutes to warm up


No, 30 seconds is plenty.

TS: check the tubes, make sure they're glowing.
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#8
Quote by SloppyJoseph
Doesn't make sense that a tube could come loose from the amp just sitting on my floor.


You mean to tell me that its impossible that when you brought it up the stairs or drove it to your house or that you've never bumped into accidentally.

Things happen, we aren't gonna point fingers at you.
Pain is an illusion.
Schecter Hellraiser C-1 w/ Seymour Duncan JB/Jazz Combo
Pitchblack | Bad Horsie 2 | DS-1 | BF-2 | ISP Decimator | DD6
YouTube Channel
#9
Quote by thsrayas
No, 30 seconds is plenty.

TS: check the tubes, make sure they're glowing.

Hmm, I always give mine a good 3 minutes, I can notice a difference in tone between 30 seconds and 3 minutes
ohai little sig.
#10
The tone might be different but the tubes shouldn't be damaged after 30 seconds.
Quote by Vincent Vega
Haikus are awesome
but sometimes they don't make sense
Refrigerator



Quote by KissingShadows
People always tell me I solo like Zakk Wylde. Thats how I know that I suck.
#11
Quote by Demonikk
Hmm, I always give mine a good 3 minutes, I can notice a difference in tone between 30 seconds and 3 minutes


Technically, I believe that the standby switch just makes a loop current run through the tubes and back into the outlet.

So it just warms it up, however, I've read and heard from some people that think the standby switch is a stupid idea and you should just play the amp real loud for about a minute and lower the volume to get the heat going.

Personally I leave it for a minute.
Pain is an illusion.
Schecter Hellraiser C-1 w/ Seymour Duncan JB/Jazz Combo
Pitchblack | Bad Horsie 2 | DS-1 | BF-2 | ISP Decimator | DD6
YouTube Channel
#12
Quote by thsrayas
The tone might be different but the tubes shouldn't be damaged after 30 seconds.

Fair enough, I take into account the fact it's usually ****-cold here too
ohai little sig.
#13
Hence the penguin lol.

Anyway. Relax, just keep the volume cranked whatever.
Pain is an illusion.
Schecter Hellraiser C-1 w/ Seymour Duncan JB/Jazz Combo
Pitchblack | Bad Horsie 2 | DS-1 | BF-2 | ISP Decimator | DD6
YouTube Channel
#14
Quote by sesstreets
You mean to tell me that its impossible that when you brought it up the stairs or drove it to your house or that you've never bumped into accidentally.

Things happen, we aren't gonna point fingers at you.



Well i mean yeah but it worked I turned it off, and then it didn't work. It didn't get moved, bumped or anything. But oh well, I guess that's the joy of tube amps.

BtW, how do you like your 52? I really like mine. Im thinking about getting an OD pedal for it though just to see how it sounds. Maybe a Maxon 808.
#15
Easiest way is to take it back if you're sure it isn't a loose tube. Let them look at it.
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#16
Quote by Demonikk
Hmm, I always give mine a good 3 minutes, I can notice a difference in tone between 30 seconds and 3 minutes


The point of the standby is a safety precaution to just to turn on the heaters to warm up your tubes a little bit before blasting them with a few hundred volts of B+. Really it's not even needed for guitar amps, I've never heard of a single case of cathode stripping, and some tube amps (like the classic 30) don't even have a standby.
#17
The overdrive channel on mine is no where near as loud as I would have expected. I have the volume on the clean channel set at about 2 but to get the same amount of volume out of the overdrive channel I have to set it to at least 7.

I just figured its the preamp tubes because for some reason mine seems to have 5 chinese 12ax7 rather than the Sovteks the manual says it should have. The only sovtek tubes I have are the power tubes, rectifier and the phase inverter, all the rest are made in china.
#18
I agree with that.^^

I have my Gain channels cranked. And my clean on about 6. The main stays about 1 or 2.
#19
Quote by sesstreets
Technically, I believe that the standby switch just makes a loop current run through the tubes and back into the outlet.

So it just warms it up, however, I've read and heard from some people that think the standby switch is a stupid idea and you should just play the amp real loud for about a minute and lower the volume to get the heat going.

Personally I leave it for a minute.

Find that person(s) and smack them immediately. They are so wrong it is not even funny, its actually kinda sad.

What the standby switch is doing is sending low voltage high current to one portion of the tubes. You want this one portion (filaments) to get super hot so electrons are essentially being boiled off the filament. (later these boiled off electrons will be attracted to the plates which have a very high positive potential).

Then you turn the amp on fully and the rest of the tubes gets voltage and you rock away.

If the tubes see voltage all at the same time you are putting huge amounts of stress on your amp and it could possible die right then and there.

There is a reason why standby switches have been on tube amps for the past 60s odd years or so....
#20
I have a 1977 Peavey VT Classic, it doesn't have a standby switch, you just turn it on and wait till the tubes warm up enough for sound to come out. Been working fine for over 30 years without a standby switch and I have only changed tubes 3 times in the past 15 years that I have owned it.

Now that said just to be on the safe side I always leave the amp on standby for a couple minutes on amps that have them.
#21
Quote by kurtlives91
Find that person(s) and smack them immediately. They are so wrong it is not even funny, its actually kinda sad.

What the standby switch is doing is sending low voltage high current to one portion of the tubes. You want this one portion (filaments) to get super hot so electrons are essentially being boiled off the filament. (later these boiled off electrons will be attracted to the plates which have a very high positive potential).

Then you turn the amp on fully and the rest of the tubes gets voltage and you rock away.

If the tubes see voltage all at the same time you are putting huge amounts of stress on your amp and it could possible die right then and there.

There is a reason why standby switches have been on tube amps for the past 60s odd years or so....


Oh alright.

I mean I've always used it but I've seen people just turn on the amp by flipping both switches really quick.
Pain is an illusion.
Schecter Hellraiser C-1 w/ Seymour Duncan JB/Jazz Combo
Pitchblack | Bad Horsie 2 | DS-1 | BF-2 | ISP Decimator | DD6
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#22
Ok so i got an update. It looks as if all of my tubes are still working. They all have an orange glow to them. And the clean channel is fine. But both gains still produce sound but at like 5% of what the volume should be. So this is really confusing the hell out of me. If i turn it up it sounds like balls, so that's not an option. I want my friggin gain channels back.
#23
It sounds like you have a ****ed preamp tube. Your tubes are warrantied for 90 days per the B52 warranty. I would take it back to GC and tell them you want new tubes or for them to give you a new head in box.
#24
Where are the preamp tubes? Sorry, told you I was new at this.

Is there a diagram I can look at?
#25
When you are looking at it from the back the preamp tubes are the small ones on the right hand side. I think you have a problem in either the 3rd or 4th one from the right since those are the 2 that are only used in the overdrive channel.

You can test this by taking the tube out of the 6th spot ( this is the tube for the effects loop and you can do with out it for a few for this test) and swap it with the 3rd tube and see if it fixes it, if not put the 3rd one back and try it in the 4th spot. If the problem goes away you know which tube to replace. Just remember where everything came from in case it doesn't solve the problem.
Last edited by Demigawd at Dec 11, 2008,
#26
Right on. Im pretty mechanically inclined and im not really scared of screwing anything up i just know nothing about this thing. I guess the only way to learn is to get up in there and get dirty. I guess ill switch some tubes out tonight and see if that works. Im going to go try and find a tube diagram for this.

To me it also seemed like it was one of those smaller ones behind the gain controls but i had no idea since they were all glowing. It wouldn't be glowing if it wasn't working right?
#27
From left to right on the AT-212

v12, v9, v8, v7, v6, v5, v11, v10, v4, v3, v2, v1

v12= 5ar4 rectifier

v6 - v9 = 6L6 powertubes

v5 - 12ax7 - Phase inverter

v11 - 12ax7 - effects loop

v10 - 12at7 - reverb

v4 - 12ax7 - overdrive channel

v3 - 12ax7 - overdrive channel

v2 - 12ax7 - clean channel ?

v1 - 12ax7 - initial preamp stage

For the AT-100 just reverse the order

The only one I am not sure of its purpose is v2, but judging from the schematic I am reasonably certain that its the clean preamp tube.
Last edited by Demigawd at Dec 11, 2008,
#29
From another forum and looking through the schematics.

Both can be found Here

The schematic there says its for the AT-100 but the AT-212 is the same, the chassis is just flipped over to fit in the combo.
Last edited by Demigawd at Dec 11, 2008,
#30
Right on dude. Thanks for the help. So from your schematic, and since I dont use any effects, I will take the 7th tube from the left and replace it with the one from either 9 or 10 spot.

Another question, If it happens to be the case, why did both OD tubes blow at the same time? Since both of my gain channels are out.
#31
Yeah you basically want to take the tube from the effects loop since for the time being it is expendable, and then try it in place of each of the overdrive channels tubes.

Both tubes didn't necessarily and most likely didn't go out at the same time, the gain is cascaded through both tubes, or in other words it goes in to v3 and is amplified then passed along to v4 and amplified even more. So either one or both may be bad but probably just one of them.
Last edited by Demigawd at Dec 11, 2008,
#33
Yeh i figured it out, they were all up in there at first. 60 bucks and 5 new tubes later, I am set. It sounds better than when I first brought it home. I think the tubes were about shot when I got it. I guess it blew one at GC too because there was an Electo Harmonix one already in there. I really appreciate all of the help. And BTW, the GC guy told me that b-52 doesn't offer any 90 day warranty on the tubes.