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Posted on Apr 29, 2017

Guitar amp signal interference.

I own a Roland VGA-7 modeling guitar amplifier,
which I purchased 4 years ago.Recently it has begun to
generate an unusual crackling noise by itself after
it is turned on, as if there were some sort of ground
interference between the internal signal paths.
I attempted to reconnect the power cable to another
receptacle, readjusted the input jack bolts,
and blasted some canned air inside the input jacks,
but nothing provided any results and the noise persisted.
What source would be causing this interference?

1 Answer

chris Taylor

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  • Posted on Apr 30, 2017
chris Taylor
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Mine did that. Found out it was the input jacks

5 Related Answers

Anonymous

  • 192 Answers
  • Posted on Apr 13, 2009

SOURCE: amp turns on but no sound even with diff guitars and cords

Hi Dan
I wish I could just say what to fix, but you can not do this at home. Line 6 is a great amp and worth the time taking it down to the music shop , to be looked at an give you a repair estimate. good luck keep on rocking in the free world. DFD

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Michial Gueffroy

  • 1140 Answers
  • Posted on May 15, 2009

SOURCE: cable broke off in the input jack

I'm pretty sure t6hat the output jack is a sealed unit(contacts inside soldered to the surface of the circuit board. You may be able to grasp the center shaft of the plug with a thin jawed hemostat or really skinny long nosed pliers and pull it out that way. Make sure the amp is off and unplugged from the wall. If that doesn't work you will either have to get it removed at a shop or disassemble the amp to remove the circuit board and unsolder the jack and replace it or get the broken plug out of the jack once it is unsoldered. I've never had a Line6 apart yet but thats probably the type of jack they used. Thats because it has to be electronically isolated from the chassis. Hope this helps.

Anonymous

  • 109 Answers
  • Posted on Aug 27, 2009

SOURCE: High pitched squeal when the input jack is used.

Sounds like your master volume is turned up too much. The channel volume will make the squealing go away(caused by high gain and humbuckers). The best thing to do is dial in your favorite presets and change the channel volume to the correct level with the master volume where you usually keep it. I use my Spider Valve at master volume at about noon and the channel volume between nine o'clock and noon. Let me know if this does not solve the problem......

Fred Yearian

  • 5603 Answers
  • Posted on Sep 22, 2009

SOURCE: Peavey 115 Low hum Low volume from input

The preamp section has a problem. It could be anything in the preamp but is OFTEN the input jack itself. They take a lot of abuse.

Also the insert jack contacts that forward the preamp to the power amp if no external FX are used can go bad.

Additional things are circuit board cracks caused by rough handling and also controls that have had the knobs mashed in which can destroy the potentiometers they are connected to.

Fred Yearian

  • 5603 Answers
  • Posted on Dec 19, 2009

SOURCE: on any channel I've begun to get a intermittant

If this has a digital effects processor read on.., I had a SIMILAR problem on a Behringer GX110.

The electrolytic filter cap for the 5 volts of the DSP effects had gone bad. The 5 volts was dipping when the DSP reset and it would repeatedly reset causing a clicking at about once a second. 50 cent part fixed it. The part is a little undersized electrically so is more prone to failure in the unit I have.

That particular one had the DSP as a seperate board with its own 5 volt supply from the main transformer.

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