Might have a problem with my fx loop.

[Jerrick]

Hey guys, a few weeks ago I read on here, or the JP forums, I dont remember really, but someone said they activate their loop, even with nothing plugged into it, and that tightens up the amp a bit more.

I like how my amp is set now, but I figured id try it out. Flip the loop on for red and orange channels, and it sounds horrible. Volume is very compressed and pinpointed, instead of being full and massive sounding. It was also really fizzy and scratchy.

So I bypass the loop and all is well.

I havent tried something in the loop yet, so im thinking I just followed some bad advice to run it with nothing plugged into it.

 

[Jerrick]

Nothing?

I tried just one cable in the loop, just going from send to return, same results, so its not my pedal, or cables. Has to be a tube problem.

Id like to stick with stock mesa 12zx7s, but are there any other brand of tubes, that are cheaper, have a good life span and wont drastically change the tone of my amp? Like the genric brand of mesa tube, same thing, different name. =p

 

[plapnab]

I agree...It has to be a tube problem. I'm not sure but I think the last 12ax7 tube powers the preamp. I'd try switching that one out.

 

[KH Guitar Freak]

Very likely the preamp valve for the loop is gone. Time for replacement...

 

[Jerrick]

Yep yep. =p

I get my tubes here tomorrow, then it off to retubing, tuning some drums, and a death metal halloween show. Should be fun.

 

[Jerrick]

Tried a new tube in V4, and tried it out, but it still seems to not work as it should.

What are some basic settings for the fx loop? I had send level at 12:00, and return at 100% which sounded good, but very quiet. I had both my orange channel volume at 12:00 and the loop master at 12:00, which I figured would of been loud, but it wasnt. I turned the loop master all the way, and still the orange channel was really quiet. Specially compared to with the loop bypassed, I dont have to turn up either channels to 12:00 and im easily heard by a drummer and bassist.

And it doesnt seem right that Id have to have the loop master maxed, and the channel volumes up around 3:00-maxed to be usable in a band practice situation.

 

[plapnab]

What are you running through the effects loop? Rectifiers dont work well with certain types multi effects processors (i.e. Pods or Boss GT series) through the loop. Maybe what you are running isn't compatible.

 

[Jerrick]

Im just trying to run a Guyatone TD-X through it and thats it. But I also get the problem justing running a short cable from send to return.

 

[livewire78602]

Just letting you know its not the tubes, been there done that, Mesa really messed up on the recto Fx loops, I even called Mesa, they sent me a tube, but it wasnt the tube, the insist its a patch cable or some effect unit, but its not, its the design of the head. Ive even patched a patch cable between send and return, volume drops dramaticaly and no punch as with nothing in FX loop. As soon as you plug anything into the loop, you loose volume, especially on the clean channel weather its clean or pushed. Very dissappointed in Mesa and there amp design. If I would of known about this I would of never bought the head. Only fix is to take it in and modify the effects loop. Now just run pedals thru the front of the head and dont even use the effects loop. Only thing good on these amps is the distortion, everything else bites!

 

[lailer75]

Just letting you know its not the tubes, been there done that, Mesa really messed up on the recto Fx loops, I even called Mesa, they sent me a tube, but it wasnt the tube, the insist its a patch cable or some effect unit, but its not, its the design of the head. Ive even patched a patch cable between send and return, volume drops dramaticaly and no punch as with nothing in FX loop. As soon as you plug anything into the loop, you loose volume, especially on the clean channel weather its clean or pushed. Very dissappointed in Mesa and there amp design. If I would of known about this I would of never bought the head. Only fix is to take it in and modify the effects loop. Now just run pedals thru the front of the head and dont even use the effects loop. Only thing good on these amps is the distortion, everything else bites!

hmm? perhaps its user error. i used a tc g-major with no issue for the last 3 years.

 

[Jerrick]

I know its not user error for my issue. Ill be using some contact cleaner on it real quick, then I need to find some off time from gigs and get it into a shop.