# hum problem



## old crow (Aug 17, 2006)

I installed a 3 prong power cord on my Premier Reverb and now it hums 
Black to on/off switch, white to transformer, green to ground.
Any ideas ??


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## Geek (Jun 5, 2007)

Hi,

You have a ground loop.

Try connecting all your equipment from one power bar, if safe for current draw.

Cheers!


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## old crow (Aug 17, 2006)

Geek said:


> Hi,
> 
> You have a ground loop.
> 
> ...


It's all on the same power bar now.


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## Wild Bill (May 3, 2006)

old crow said:


> I installed a 3 prong power cord on my Premier Reverb and now it hums
> Black to on/off switch, white to transformer, green to ground.
> Any ideas ??


Swap the black and white wires.


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## old crow (Aug 17, 2006)

Wild Bill said:


> Swap the black and white wires.


I'll try it, but I thought having the hot direct to the trannie is a saftey issue ?
No fuse on this beast so maybe it makes no diff....???


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## Wild Bill (May 3, 2006)

old crow said:


> I'll try it, but I thought having the hot direct to the trannie is a saftey issue ?
> No fuse on this beast so maybe it makes no diff....???


No fuse? Well, it's not really a safety issue. It's an electrical code issue. That rule didn't apply when your amp was made. After all, a 2-prong plug could go in either way so who could tell when the hot was direct to the tranny?

I would put a fuse in! Why not? Put it in the hot lead if you're worried about it.

:food-smiley-004:


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## old crow (Aug 17, 2006)

O.K. I've tried everything. now it's back to the black going to the switch.
Ground is now on trannie bolt.
I cleaned the pots and tube sockets, found a loose connection on the output cord , so also replaced it.
It may be a bit quieter now but still pretty loud and seems a bit microphonic.
Would the next step be to replace the old elecrolytic cap. ??
Thing is it was fairly quiet before I monkeyed with it.


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