#1
Hi! I have a B-52 AT112 Combo and just today I realized that after playing for a while, the volume fades out often. Like it doesn't cut completely, but it just fades out slowly and makes the sound weaker and weaker (if that makes sense). And when I turn it off and turn it back on, it works fine for about 15 minutes, then it does the same thing and the volume fades out slowly to a very weak sound.

I'm pretty sure this isn't a cable problem, because cables would just cause crackles or would just not produce any sound.

BUT I'm pretty positive this is a tube problem. This is my first tube amp and I really don't know much about tubes. Could this be the pre-amp tubes or power tubes causing the trouble?

According to the amp stuff, this is what it has:

Power: 2 – 6L6 / 5881
Preamp:4 – 12AX7
Phase Inverter: 1 – 12AX7

Also, would I need to bias this amp?, and how would I do that on my own (with a multimeter I assume?) ( and considering I don't have any spare money for a tech to do it)

Sorry for the long "problem".

Thank you!
#2
How long since the last time it was re-tubed?

-Gibson LP VM
-Silvertone Kentucky Blue
-MXR CC Delay
-Ibanez TS-9
-Egnater Rebel 20
-Avatar 1x12

My rig is simple
Haha. UG's Chuck just said chuck. haha
You're not truly playing guitar unless you know theory.
#3
Your power tubes are probably crapping out.

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[quote="'[BurnTheDusk"]']Boss pedals may be built like tanks but I would rather buy a cardboard box that is on my side than pay for a tank that is working against me.
#4
definitely sounds like a power tube problem.

next time this happens look at the power tubes, see if you can see any red plating going on.
#5
Yeah I'll check tomorrow when my parents aren't asleep. Does this mean I just need to change my power tubes? Do I have to change my pre-amp tubes too? I heard it was best to just retube everything.

How are these power tubes? (Amp uses 6l6's)
http://accessories.musiciansfriend.com/product/ElectroHarmonix-6L6-Matched-Power-Tubes?sku=210090


And would I have to take it to a tech to bias this? I have a multimeter and I can do it myself if it's not that difficult.

Thanks
#7
Don't buy tubes at MF or any similar place because they are not tested properly there.

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THE SINE WAVE SURFER σƒ τλε τρπ βπστλεπλσσδ

╠═══════╬═══════╣


[quote="'[BurnTheDusk"]']Boss pedals may be built like tanks but I would rather buy a cardboard box that is on my side than pay for a tank that is working against me.