Dirty power question

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mike9
Posts: 92
Joined: Fri Mar 09, 2007 9:27 pm
Location: Chatham, NY

Dirty power question

Post by mike9 »

My Omega modded HotRod Deluxe has been making funny - real bad hum idling and some nasty buzz with some pickups and guitars. I figured something was FUBAR and took it to work with the intention of shipping the chassis and tank down to Jim at Omega for fix and some upgrades.

On whim I plugged into the outlet at work - perfectly silent . . . Hmmmm . . . I tried several different places, but none duplicated the buzz I get at home.

I nixed the power strip it was on and went directly into the wall and it's much better. I'll check the ground connection at the outlet and the available power - it is't not up to snuff is there a power conditioner I can get?
"I fought the Tone . . . and the Tone won"
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Phil_S
Posts: 6048
Joined: Tue Oct 23, 2007 10:12 pm
Location: Baltimore, MD

Re: Dirty power question

Post by Phil_S »

Power strips can be problematic. I don't really understand this, but my understanding is that they are designed to prevent voltage spikes from damaging things like computers and other sensitive equipment. I'd think that tube amps with comparatively monster size transformers aren't really vulnerable in the same way as a computer and you should discontinue use of the power strip.

Interestingly, I own a HP 2550L color laser printer and had the fuser go bad on me (ugh, expensive). In doing some reading, I discovered that HP recommends going direct to the wall supply and specifically says the use of a surge protector is not a good idea. Apparently, surge protectors do more than just prevent spikes. In reading between the lines, I suspect a bit of a brown out effect. Perhaps your filament supply "notices" this? Another possibility is that you might think of the surge protector as a passive device, but it isn't quite as passive as it looks, contributing something unwanted?
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Structo
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Joined: Wed Oct 17, 2007 1:01 am
Location: Oregon

Re: Dirty power question

Post by Structo »

Mike,
A couple weeks ago the Stupid Deal of the Day at Muscians Friend was a Nady PCL-800 power conditioner.
For $40 I thought why not.
It is the standard rack mount size and I'll bet if I was to pop the cover on that thing there would be a MOV and maybe a choke.
Tom

Don't let that smoke out!
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LOUDthud
Posts: 464
Joined: Tue Sep 25, 2007 9:27 pm
Location: Texas

Re: Dirty power question

Post by LOUDthud »

I would suspect an open ground connection in your wall outlet. The outlet strip most commonly has a cap from each side of the line to ground. If there is no ground, the third wire floats at half the line voltage.

I rented a house once that had aluminum wiring and none of the grounds in the outlets were hooked up. :evil:
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