Help, My recto exploded today,

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lowalkoroc

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Hey guys, this is my first post here, and i was wondering if you could help me figure out what happened to my Mesa Single Rectifier today. Ive owned my recto for about a year and a half and have had no problems with it untill today

I was playing it today at at about half volume, modern mode, Master 10:00, Output 12:00

and all the sudden i heard a crackling wimper sound and my amp died and shut down and black smoke came out of the back, and it loooks like 3 out of 5 of my pre-amp tubes and both my power-amp EL-34s turned a lovely shade of charcole black on the tops and they smell like sulfer like in firecrackers or somthing, which is strange, i just changed the power tubes to Mesa EL-34s this past x-mas and i wasnt running anything i wasnt suppoed to into into the amp, (and yes i changed the Bias switch to el34 when i changed tubes)

Also the white circular base that the left EL-34 gets plugged into also got charred black.

I am also concerned that the amp itself shut down when this happend (power light went out and everything) and what that exactly could mean.

This is my first bad experience with a tube amp, as ive had no problems before and just wondering if anyone can help me figure out what went wrong, heres some pictures of the carnage :cry:

i took the pre-amp tube covers off just to inspect them after it happend

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Ouch!

Hopefully it was just a tube problem. I'd probably just change the tubes and fuses (it may have internal fuses also) and see what happens.

If you can afford it, the best alternative would be to have an amp tech check it out for sure.
 
The black charcoal at the top of the tubes is normal. It happens when the getter in the tube is flashed. The getter is the halo on the top and it absorbs stray oxygen from the tubes to keep them an oxygen free vacuum. The two do however look odd. The power tubes look fine, but it is an internal issue that causes them to go bad.

Now, the bad news is, you have had a catastophic power tube failure that probably took out the screen grid resistors and the power circuit board with it. It may have been a blown filter cap or bias supply caps/resistors as well.

By the looks of the power tube sockets they both arced very badly. Hopefully, your fuse saved the output transformer. The sockets will probably have to be changed as well. It is very difficult and time consuming to remove all that carbon. Carbon is not a conductor of electricity, so if you do not get all of it, you may blow more tubes and have intermittent power amp issues. They are PC mount sockets and are mounted to the PC power tube board. The smell was probably the resistors or the circuit board or both.

If this amp is under warranty I would call Mesa and get an RA. Sadly, this is not a first timer retube and play deal. All that carbon is a bad sign.

Good Luck,

Ed
 
Well Ive only had my amp for a year and a half and i sent the warranty card in as soon as i got it, so its definatly still under warranty
 
If you are still in warranty and it appears you are, i would definately send it in and let them fix it.
 
i brought it into a certified mesa repair station and it turns out it was a faulty mesa EL-34 (kinda mad, they were brand new, only a month old), that somhow exploded and lost all its gas, (the day after i took the pictures the tube turned a milky white color. The smoke was from the socket melting on the surface, luckily nothing damaged the circuit board the socket was attached to.

So the amp tech cleaned it out as best he could and put Svetlana El-34s in it and it works fine, i didnt want to put new tubes in myself and turn it on because i didnt know if it was the amp that was the problem so its a good thing it just turned out to be a bad tube and nothing worse

The mesa tubes are under warrenty for 6 months so id like to get a refund or them replaced, but guitar center wont take them back so i have to call mesa directly and hopefully they will accept that they made a bad tube and not make excuses like "it left the factory good" or whatever and il send them out and they will hopefully send me a new pair

anyways thanks for all your help and advice
 
lowalkoroc said:
The mesa tubes are under warrenty for 6 months so id like to get a refund or them replaced, but guitar center wont take them back so i have to call mesa directly and hopefully they will accept that they made a bad tube and not make excuses like "it left the factory good" or whatever and il send them out and they will hopefully send me a new pair
I have dealt with Mesa two separate times concerning bad tubes and they replaced them without any trouble. Give them a call and let them know what happened and they should mail you a new pair of EL-34s. You might need your receipt to prove the date of purchase.
 
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