Buzzing power transformer

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Dave1992
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Buzzing power transformer

Postby Dave1992 » Sun Feb 05, 2017 10:01 am

Hi guys!

I've noticed that the pt on my '11 1959slp started buzzing the other day. The buzzing can be heard while I'm playing the amp ( so it's as loud as my guitar) and on stand by (not through the cab but the transformer itself) ... I've tried a few different power outlet, swap some preamp tubes, checked the filter cap mounted on the amp and there's nothing I can see that could have gone bad.

But do you think that the pt might be going bad? The amp is full stock except for new power tubes that have been changed around 6 months ago. I usually slave the amp with a loadbox to another power amp (SS)

Let me know what you guys think!
Thanks alot :toast:

danman
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Re: Buzzing power transformer

Postby danman » Mon Feb 06, 2017 4:36 pm

Does it feel too hot to touch for several seconds after you have been playing the amp for awhile? This might indicate an issue with the PT or excessive current draw somewhere in the power supply. Some PT's have been known to emit a slight buzzing sound though. I had a DSL 50 for several years that would do that also. The amp performed perfectly every time but the PT always emitted a slight low frequency buzzing sound.

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Dave1992
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Re: Buzzing power transformer

Postby Dave1992 » Mon Feb 06, 2017 5:58 pm

danman wrote:Does it feel too hot to touch for several seconds after you have been playing the amp for awhile? This might indicate an issue with the PT or excessive current draw somewhere in the power supply. Some PT's have been known to emit a slight buzzing sound though. I had a DSL 50 for several years that would do that also. The amp performed perfectly every time but the PT always emitted a slight low frequency buzzing sound.


Back when I was gigging alot, the amp would get REALLY hot. Even with the pack pannel off, the cabinet near the transformer would be really hot. I've never touched it though...

As for the buzzing, it's not a really low frequency buzz but more like when you unplug you guitar cable actually.

danman
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Re: Buzzing power transformer

Postby danman » Tue Feb 07, 2017 4:16 pm

PT's will get hot when running the amp for awhile. Heat radiating from the power tubes will also warm up everything around them. If the PT gets so hot that you can not place your hand on it for at least a few seconds, there could be an issue. If the buzzing just recently started out of the blue, it might be a good idea to have a tech check over the power supply. The amp that I mentioned had come from the factory with that noise. It was a very low level buzzing sound. You could only hear it if you were in a quiet room with the amp on.

sixpakldp
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Re: Buzzing power transformer

Postby sixpakldp » Thu May 25, 2017 10:18 pm

Are you sure it's the transformer and not a bad ground? When you reference that it sounds like a cable plugged into the amp, you can get that when you have a bad ground.


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