Marshal JVM head loud hum!!??

[Rob Tahan]

So my JVM head in OD1 And OD2 has been humming REALLY loud with the gain on. Any ideas as to why?

 

[D-Rock]

If it just started, I would expect the preamp tube that is designated for the gain channels has gone bad on you.

 

[Rob Tahan]

Anyone else?
Or anyone that has had a similar problem and fixed it?

..and thanks btw, i will check the preamp tube

 

[FortinAmps]

Hey Rob,
There is a Marshall JVM Service Bulletin out for hum. Do you have Midi and multiple effects connected to your JVM? If you do then the Service Bulletin might be your ticket. If it hums with no MIDI devices or effects connected then it is most likely a preamp tube issue.
Cheers,
Mike

 

[kannibul]

So my JVM head in OD1 And OD2 has been humming REALLY loud with the gain on. Any ideas as to why?

Try eliminating the source of the hum, that'll usually do the trick...



What have you tried so far?

 

[kannibul]

Hey Rob,
There is a Marshall JVM Service Bulletin out for hum. Do you have Midi and multiple effects connected to your JVM? If you do then the Service Bulletin might be your ticket. If it hums with no MIDI devices or effects connected then it is most likely a preamp tube issue.
Cheers,
Mike

What does the service bulletin say / warrant?

 

[crabby]

mine hummed and was noiset , the fx loop sucked.......i fixed it...i sold it

 

[maiden_fan]

I had a hum from mine a couple of time, it was my wah causing the first time, and a preamp tube the second. The amp itself is pretty quiet.

cheers tony

 

[FortinAmps]

Here are the 2 Marshall Service Bulletins that are currently issued





Cheers,
Mike

 

[Rob Tahan]

Thanks guys!!
That was very helpfull! Im hoping it will be the preamp tube. I'll find out soon though.
Crossing my fingers.