is toroidal transformer hum,buzz dangerous??

[gbolly]

i recently changed the chassis of my gainclone to a new on and kept the wiring intact, but now i get an audible hum/buzz from both transformers.

ive checked and double checked the rubber washers for insulation,

i have two identical single secondary toroids working together at the moment.

is this dangerous, there is a slight burning smell after a couple of seconds as well.

 

[timpert]

there is a slight burning smell after a couple of seconds

uhm... yes, I would say this is dangerous! Stop using it this way.

First, check the amp with a large lightbulb in series with the primary. It should flash briefly upon turn-on and then dim quickly. If it lights up continuously, something is wrong. It might be an accidental short in your wiring.

It might also be that you unwillingly and unknowingly created a shorted winding around the core by the way the transformer is mounted. If you use a U-clamp with a metal bolt through the center of the toroid, this happens easily. Can you post a picture of your transformer mount?

 

[Gcollier]

If your new chassis is conductive, you might want to check and see if you have created a shorted turn in the transformer. If the mounting bolt passing through the center of the transformer creates a "loop" with the chassis you have a problem.

 

[gbolly]

thanks for all your replies, i tracked down the transformer buzzing to one half my dual single secondary toroidals pair.

one of them has a loose winding which is fine when wired directly and normally. but in my previous split power amp and power supply design, i implemented a

 

[gbolly]

safety earth loop in the power supply box.

now that ive combined both preamp, power amp and power supply into single box, using the safety earth loop breaker now causes the hum in the transformer.

i removed it from the system and there is no sound coming from the transformer at all and even tested the amp connected to speaker with no input and so far the output is totally silent.

so ive completely disregarded the safety loop.

now im not sure where to connect the audio ground (power amp zero line to ) as this was connected to one end of the safety loop