brand new 5150 III 50W head - third channel went out

[clags]

Hello, I got a brand new EVH 5150 III 50W head a week ago. I was playing yesterday and the third channel suddenly dropped out on me. There is now only a faint volume of playing, it gets a little louder if I crank the volume knob all the way up to 10 but the sound is still really weak and thin.

Channels 1 and 2 are still perfectly fine and working as expected. I pulled the fuse out and it looks ok, not sure what else I can test to help troubleshoot. Has anyone experienced anything like that and offer any suggestions? The only nearby authorized service center for Fender amps near me has a huge back log -- I'll do a warranty claim if I can't figure out what's wrong but was crossing my fingers it's something simple I can figure out.

 

[dead-pan]

If you have any 12ax7 tubes lying around try replacing one a time.

 

[shredhead7]

Download the manual and look at the tube layout. Look for the preamp tube that is for that channel and replace it. It looks like either V2, V3, or V4 went bad.

http://support.evhgear.com/schematics/E ... ctions.pdf

 

[clags]

Download the manual and look at the tube layout. Look for the preamp tube that is for that channel and replace it. It looks like either V2, V3, or V4 went bad.

http://support.evhgear.com/schematics/E ... ctions.pdf

Thanks, can you tell me which one of these tubes is the proper one? https://www.sweetwater.com/store/search ... CC83+12ax7 . (Just googled for what the specs page lists -- 12ax7 ecc83)

 

[fek]

Thanks, can you tell me which one of these tubes is the proper one? https://www.sweetwater.com/store/search ... CC83+12ax7 . (Just googled for what the specs page lists -- 12ax7 ecc83)

Any 12AX7 will work. Each manufacturer will have a slightly different sonic characteristic. In short, you can buy the inexpensive one and just fine.

 

[232cap]

try v3 or v4 first

 

[clags]

try v3 or v4 first

Will do. Got some tubes ordered today so hopefully try to swap them before the weekend. If no luck I'll take it to a service dealer.

 

[kurtsstuff2003]

try v3 or v4 first

Will do. Got some tubes ordered today so hopefully try to swap them before the weekend. If no luck I'll take it to a service dealer.

Welcome to the world of tube amps..You'll be buying more tubes and more tube..and more tubes. Get my drift??..lol!!

 

[Shask]

Yep, I agree. Try to replace the tubes only for that channel first before going to something more serious.

 

[Norton666]

I've repaired a few of these. Great amps , but RARELY does simply replacing a tube solve your issue, long term. If it is brand new , exchange it under warranty , get a new one and be done with it

 

[PhloridaMan]

I mean if it's brand new, why not do as Norton said and exchange it or have it repaired? EVH's come with 5 year warranty's... I have one sitting next to me right now lol

 

[clags]

I mean if it's brand new, why not do as Norton said and exchange it or have it repaired? EVH's come with 5 year warranty's... I have one sitting next to me right now lol

Yeah I will likely just have to do that. I was hoping there might be a simple fix to not be without an amp for a long time because of a few reasons. The shop i bought it from is really far away so taking it back there is not a simple drive to the local music store. The option of taking it to a certified fender dealer is that the only local place to me has like a 6 week backlog to do any sort of diagnostic on it (really).

 

[D-Rock]

I've repaired a few of these. Great amps , but RARELY does simply replacing a tube solve your issue, long term. If it is brand new , exchange it under warranty , get a new one and be done with it

In your opinion then, what would be the next thing you would look at if a tube swap didn't solve the problem?
A solder connection or circuit failure on the PCB somewhere?

 

[Racerxrated]

Honestly, any new tube amp issue is going to be tube related 99% of the time. New production tubes are shit. I’ve never had any older used power or pre tubes cop out. Only the newer crap. Invest in some good vintage tubes, and used ones won’t cost as much as you think. They tend to have a lot of life left. Just buy from a reputable seller here or elsewhere. Yes the NOS stuff is spendy but strong used stuff isn’t.

 

[napalmdeath]

Its a preamp tube. I had one do the same thing. Tube, tube, tube. Don't listen to the horseshit horror stories, or spend a fortune on NOS tubes. Get some from a reputable dealer, and be done with it.

Like above, 99% of tube amp issues are tubes. Especially the cheap, non-labeled, non-tested bottom of the barrel JJ's in the EVH.