Valvestate 8100 head buzzes when turned on


I recently got myself a Marshall Valvestate 8100 head, which sounds amazing for a hybrid amplifier. Now there is one problem with the amp, and that is that there is a low buzzing sound when I turn it on. It does not get louder when I turn up the volume or gain, and it doesn't disappear when I switch channels, which means that it can't be the pre amp tube that causes the problem. I don't use a grounded power socket, but my other amp (an Orange Tiny Terror) doesn't hum so I don't think there is a problem power wise. My guess is a bad soldering joint somewhere in the amp, but I have no idea where to start looking. Is there someone who can tell me how to get rid of the buzzing? And how do I identify a bad soldering joint?


asked 29 Apr 2018 at 08:07 PM

Brian Legdeur
So I just opened my amplifier to see if there was anything wrong with it, and everything looks in order. The capacitors look clean and the other components too. Except for a few soldering joints at the reverb circuit, the power supply and the two line out jacks. The joints are done ok, not like a cold joint or anything like that, but they are overheated. I can see the orange/brown glow over a few of them. Can this cause a humming sound? And how do I clean an overheated joint? - Brian Legdeur 30 Apr 2018 at 06:56 AM
Answers: 1


Hello Brian,

Regarding your 8100, the fault probably lies within the low voltage power supply, it could be a faulty smoothing capacitor or a diode within the supply. We would recommend that you have this looked at by  a qualified engineer.


Kind Regards

Marshall Support 

answered 30 Apr 2018 at 07:38 AM

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