Is 120vac too close to output transformer a problem?

Ronno25

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I'm working on a new p2p build in a very small chassis. My 120v AC power transformer primary line is going to have to run quite close to my output transformer. Is this going to be a problem for noise, etc? I've never had to deal with this consideration before. TIA.
 

Jon Snell

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By your question, I think you mean the position. If you do then as long as they are mounted out of phase by 90° the interference will be minimised.
The windings must not be in the same plane. If they are, it'll hum even with no valves installed.
Hope that answers your question.
 

Ronno25

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@Jon Snell Thanks Jon. What I meant were the leads traveling to and from my power switch, fuse, and 120vac neon lamp will be running very close to my output transformer.
 

dogmeat

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twist the wires. they have minimal effect, but I twist them anyway

when I build, I place the output tranny by connecting the coils to a head set and listening. put line voltage on the power tranny and listen for the hum as you move and change position of the O/T
 

Len058

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It shouldn't matter. I tried it during a headphone OT test, like dogmeat describes, and had to put the OT, almost on the power socket to hear hum. Outside the chassis, the power lines and heater wires, inside the chassis didn't cause hum.
 
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Blrfl

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Likely not much of a problem. If you're that concerned, shielded and properly grounded power cable past the sensitive bits wouldn't hurt.
 

2L man

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When you play most likely you won't notice anything but the electromagnetic field your amp OT produce and inductively transfer to Mains might come thru other gear there are on stage? Thats why it is best to follow good building principles!

Definitely wire all secondary return current to Common bus or few Star wires. Using Chassis to flow return current should not be used because it will make noise to your instrument and to Mains Safety Earth.
 
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