buzzing amplifier

[fenderman]

need help with guitar amp,just buzzes even when guitar plugged in theres nothing but this noise ive tried a different speaker so i can exclude that, it is just one volume level and doesnt change when any of the switches/knobs are turned, i havent got a test meter not that i know how to use one proper anyway,any ideas would be helpful ( apart from skip it get anew one or similar)thanks to one and all....

 

[RF Lighting]

Does it still buzz when there is nothing at all plugged into it?

 

[breezer]

check the plug connections, make sure all are tight and also try plugging it in some where else.

oh and has it always done this?

 

[davy_owen_88]

Have you tried using a different (high quality) guitar cable? Is the amp a combo or a separate head and cab? Is it a tube amp? What type of pickups? Is the guitar properly shielded? Have you got the gain set to max? Do you have any effects in the signal chain?

 

[tim west]

When I used to have to test a lot of musicians equipment for shows I used to find loads of guitarists had removed the earth from the terminal inside the plugtop to stop the hum. I used to replace it before testing knowing full well that they would remove the earth again once i had gone.

 

[streetlighter]

Any other items plugged into the circuit can also cause a hum to be herd from the amp. I had it caused by computers and fridges mainly on my Fender Princeton amp.

 

[Space cat]

It's not clear from your post but I think you're saying that you can't get any guitar sound out of it. True or false?

it is just one volume level and doesnt change when any of the switches/knobs are turned

This tells us that the fault must be after all these controls, probably in the power stage. How much do you know about electronics?

 

[fenderman]

thanks for all your comments.
its humms/buzzes with nothing pluged in
it does not alter volume if any controls are moved
all guitars are sound
its the same where ever it is pluged in
all plug conections ok
it is one complete unit (no cab and seperate head)
it is made by KUSTOM

i have noticed 2 leds inside (that do not show on the outside like the power switch) do not come on they are at the side of the overdrive switch

i can see that the speaker wires have been resolderd on the board( not a good job) but im sure its not that but cant prove it without test meter

is it possible this could be caused by a fault on any of the varible resisters (volume n so on?)

thanks again folks!

 

[fenderman]

oh by the way i dont know alot about electronics but im learning all the time!

 

[plugwash]

There are lots of faults that could cause it but without proper test gear (you could really do with a scope) and some understanding of how amplifier circuits work it is unlikely you will be able to trace the fault and it would be almost impossible to help you remotely.

I would suggest that you try and find someone locally who knows how to fix such things.

 

[tim west]

When I used to have to test a lot of musicians equipment for shows I used to find loads of guitarists had removed the earth from the terminal inside the plugtop to stop the hum. I used to replace it before testing knowing full well that they would remove the earth again once i had gone.

 

[davy_owen_88]

What model is it? I know that one of the kustom practice amps has a preamp tube, and if that is knackered it will cause excessive noise.

 

[fenderman]

What model is it? I know that one of the kustom practice amps has a preamp tube, and if that is knackered it will cause excessive noise.

Are you able to describe the pre amp tube to me and where abouts it should be on the board if you can? thanks

 

[gas4you]

As an ageing bass player, I used to find that buzzing through any amps was usually down to an earth loop problem.

 

[tim west]

As an ageing bass player, I used to find that buzzing through any amps was usually down to an earth loop problem.

tim west wrote:

When I used to have to test a lot of musicians equipment for shows I used to find loads of guitarists had removed the earth from the terminal inside the plugtop to stop the hum. I used to replace it before testing knowing full well that they would remove the earth again once i had gone.