#1
Ok, I just had a bit of a problem with my amp. Its just started making a loud bang from time to time.

It's a Harley Benton GA5 (Epiphone Valve Junior clone).

I'm thinking one of the tubes may have gone (though I've only had it like 3 months), but haven't had much of a chance to look at anything (when I turned it round to have a look it started giving a 4/4 beat, so I panicked and turned it off!).

One thing I did notice was that one of the tubes was (I think) glowing slghtly.

Help please!

#2
I don't know really, but I know the voltage that it's meant to run off is 240v, and in the UK you only have 230v. That might be the problem.

I dunno though.
Cam Sampbell's my hero
#4
A bang?

That ain't never good.

I seriously doubt your tubes are red plating. Although I suspect it might be an output transformer issue.

Also if you amp is rated to run at 240v... it has no issue accepting a current with a voltage of approximately between 220v - 260v (variation subject to the different power transformers in amps).
Quote by Blompcube
it's so cool to hate Gibson, even the federal Department of Justice hates them.

( )( )
( . .) This is Bunny. Copy and paste Bunny into your
C('')('') signature to help him gain world domination.
#5
Everyone out of ideas?

No suggestions for what I should do?

Last edited by EL2T at Nov 2, 2009,
#7
Sounds like you might have some high voltage arcing. You would need to remove the chassis from the cabinet and run it (connected to the speaker) in a dark room. When you hear a bang you may be able to see a flash on the circuit board. Also examine the circuit board to see if there are any dark smudges of carbon that would indicate arcing.

A bad tube may be causing the problem as well. You only two tubes so it might be worth getting them.
#8
Quote by fly135
Sounds like you might have some high voltage arcing. You would need to remove the chassis from the cabinet and run it (connected to the speaker) in a dark room. When you hear a bang you may be able to see a flash on the circuit board. Also examine the circuit board to see if there are any dark smudges of carbon that would indicate arcing.

A bad tube may be causing the problem as well. You only two tubes so it might be worth getting them.


If it was high voltage arcing, how could I solve the problem?
#9
Depends on where the problem is occurring. If it's a tube, replace it. If it's a tube socket then replace it. If it's on the circuit board try to see if a component like a cap looks bad or damaged. Replace the component.

If nothing looks bad but evidence of arcing is on the board start by cleaning the area. It's possible for an arc to occur because of contamination that is conductive. The arcing can create carbon, which is even more conductive leading to more arcing.