ugggh Mark V crapped the bed. Halp!!

[sean106ESP]

Hey everyone.

A few weeks ago my Mark V started to sound....well..."skanky". LOL

The cleans are very weak...lots of break up.....no head room....just not the clean sparkle I was used to (I adore the pristine clean channel one achieves). Also the dirty channels (I usually play on Mark IV/V mode with the gain pretty saturated and scooped (I guess Metal-like tone )....and that also sounds thin as hell....lifeless....no balls or thump.................and even kinda fizzy.

First I thought it was the pre-amp tubes so I replaced all of them with new Mesa 12AX7's and no dice. Still the exact same tone. (I know at least it is not the guitar as I have a few and it sounds the same on all with the same pup's)

I am wondering if anyone has experienced the same thing over time? Nothing per say happend. Just playing at home over time I noticed the sound getting worse and worse. Next up is try to change the power amp tubes. I don't have a spare 5U4G tube but I have the extra 6L6's it came with. I changed them out a year or so ago for EL34's. Any advice? Much thanks in advance.

 

[sean106ESP]

Actually I found a spare 5U45G tube and changed it as well as the power tubes back to the 6L6's. Grrr...still sounds horrible.

 

[MrMarkIII]

Did you change all the tubes at once?
Don't do that.
Change out tubes one at a time.
Otherwise, you have no idea which tube, if it is a tube, is causing the problem.
Get the manual out, and start with factory settings.
This way, you should be able to tell if some knob or switch is somehow in the wrong place.
Slow and steady as she goes.
Finally, do not try to judge tube performance by how much or little it is "glowing". Makes no difference. If you suspect a tube is failing, pull it and replace with one that works. One-At-A-Time. If there is no change, put the original back in its socket and move on to the next tube in line. One-At-A-Time.

 

[sean106ESP]

Did you change all the tubes at once?
Don't do that.
Change out tubes one at a time.
Otherwise, you have no idea which tube, if it is a tube, is causing the problem.
Get the manual out, and start with factory settings.
This way, you should be able to tell if some knob or switch is somehow in the wrong place.
Slow and steady as she goes.
Finally, do not try to judge tube performance by how much or little it is "glowing". Makes no difference. If you suspect a tube is failing, pull it and replace with one that works. One-At-A-Time. If there is no change, put the original back in its socket and move on to the next tube in line. One-At-A-Time.

Yeah I did do it all at once. You are right as I need to do it slowly. I just was not wanting to take the time to pull the powers out....then swap a pre-amp....put back the powers...play...repeat. Will try again tonight doing it one at a time or try my local shop to have a look. They are a local shop that does good work and lol tends to not bs you when it comes to amp repair.

 

[screamingdaisy]

Your description sounds like dying power tubes, but since you say you've changed them already then I don't know what to say.

 

[sean106ESP]

Your description sounds like dying power tubes, but since you say you've changed them already then I don't know what to say.

Thanks. Yeah I am kinda at a loss. If it is the power tubes then both sets of EL34's and 6L6's have a dieing tube. Could be?

 

[screamingdaisy]

Have you checked the loop send level at the rear of the amp? When I first got mine that knob was jacked up to 10 and it sounded like thin, fizzy ***.

Beyond that, I'd test it out with a couple different guitars and cables just to confirm it isn't something other than the amp.

 

[sean106ESP]

Have you checked the loop send level at the rear of the amp? When I first got mine that knob was jacked up to 10 and it sounded like thin, fizzy ***.

Beyond that, I'd test it out with a couple different guitars and cables just to confirm it isn't something other than the amp.

Hmmm.....I think you may have nailed it.

I played with the FX level knob and nothing. Then I switched it to hard bypass and the clean tone went back to its sweet spot (weird as I had not heard it in a while) But I had no FX loop obviously and I love running just a super chorus in the loop.

Well I switched back from hard bypass to FX loop engaged and boom....seems back to normal. For now at least.......

So I am wondering if my loop is going/gone? :?:

Thanks guys.

 

[Chester]

Loop or perhaps cables

I had a fizz / crackling issue recently and instinctively went for the tubes. Nothing wrong with them. Changed cables, and bang - fixed. The MKV is a sensitive beast, and picks up on any interference in the signal chain. Worth checking out the cables first

 

[sean106ESP]

Loop or perhaps cables

I had a fizz / crackling issue recently and instinctively went for the tubes. Nothing wrong with them. Changed cables, and bang - fixed. The MKV is a sensitive beast, and picks up on any interference in the signal chain. Worth checking out the cables first

Thanks. yeah forgot to mention I tried a few different cables. Was OK last night give it another test run.

Weird as I....*runs for cover*...I was using the HD500 for a few months in the FX loop. Mainly because I got used to loving it for recording and got used to having all these FX I never used on the fly. (I am not into pedals and wire clutter. Was nice and simple. However I got sick of tweaking and just could not get tones I really liked. What I am getting at, as I ramble, is that I almost forgot what the wonderful overdrive the MV has and back to tweaking as if I first got it.

 

[thunda1216]

spray some contact cleaner on a plug and work it in and out of the effects loop jacks several times to clean any crap/corrosion out and see if that helps.