# JTM45 Trouble



## ThunderCoveRocks (Sep 24, 2009)

Hey everyone,
I'm having a problem with my JTM45. Actually I'm not even sure if it is a problem with that. This is the line, from my les paul to the JTM45 to a 2x12 speaker cab. 
When I turn the amp on with standby off and all, a hissing comes through the speakers when the volume is anywhere but 0. The only other way I can get it to stop is to touch anything metal on my guitar or hold the strings.
Anyone have any idea what could be wrong??
Thanks
JTM45er


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## ThunderCoveRocks (Sep 24, 2009)

Alright all channels have the hiss and also when I turn up my presence pot, the hissing gets more intense and when I'm rotating the knob it makes a rubbing sound like a vinyl rubbing with a needle. Then when presence is turned to 10 the amp squeals.


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## Greenbacker (Mar 29, 2007)

Sounds like a grounding issue and maybe microphonic tubes.


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## greco (Jul 15, 2007)

Have you tried different guitars, cables and/or speaker cables?..just to try and isolate the source. Because the hissing decreases when you touch the strings, I would agree with Greenbacker...that it might be a grounding issue...the fun will be trying to sort out where it is. You could check this quickly with a multimeter, if you have one and know how to use it.

Cheers

Dave


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## joe-mojo7 (Jun 2, 2010)

Is this the re-issue? Sounds a lot like mine.......


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