Problem on OD1 and OD2 in yellow and red modes. Help diagnose?

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Stinger
Private Parties
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Joined: Mon Jan 26, 2009 1:47 pm

Problem on OD1 and OD2 in yellow and red modes. Help diagnose?

Post by Stinger » Tue Dec 31, 2019 4:59 pm

Hello folks,

My son's JVM410h has developed a problem so I am wondering if any of you might be able to help diagnose the issue?

Firstly, the Clean and Crunch channels on this amp work perfectly fine in all modes. The problem he is having with this amp only occurs on OD1 and OD2 in yellow and red mode. Green mode on both these channels works fine.

What the problem is is that on OD1 and OD2 in yellow or red mode, the signal sounds fine when picking the guitar with low to moderate intensity; however, as the picking strength becomes fairly strong the signal begins to break up and becomes all garbled and buzzy and the volume drops.

Any ideas? Thanks.

okgb
Club Circuit
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Location: The Great White North-Winnipeg

Re: Problem on OD1 and OD2 in yellow and red modes. Help diagnose?

Post by okgb » Wed Jan 01, 2020 9:08 pm

Having a spare tube is not a bad idea, I would suggest getting a new 12ax7 and try swapping it into the V2 , and v1 spot one at a time
and see if that helps, it's the easy solution , if it works.
Amps JVM 410H [too many mods to mention ] '73 50w lead, 70's vibrochamp , mesa mkIII U.S. Vox pacemaker
Rock , pop rock & Blues style's mainly played
Gtr's Musicanman " Luke " wolfgang [ carved top w pearly gates ] Hondo lazer , Warmoth strat
Fx t.c. 2290 , Lexicon tc verb
Pedals tbone plexi , t.c. chorus , various handmade & usual suspects t.s. , zen , CB wah ..........

Stinger
Private Parties
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Joined: Mon Jan 26, 2009 1:47 pm

Re: Problem on OD1 and OD2 in yellow and red modes. Help diagnose?

Post by Stinger » Fri Jan 03, 2020 3:56 pm

Okay. Thanks. I will give it a try.

Stinger
Private Parties
Posts: 223
Joined: Mon Jan 26, 2009 1:47 pm

Re: Problem on OD1 and OD2 in yellow and red modes. Help diagnose?

Post by Stinger » Tue Jan 14, 2020 1:52 am

Well I swaped out the tubes in v1 and v2 with new one and re biased the amp but to no avail it did not correct the problem.

Do you are anyone else have any other suggestion what the problem might be?

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