Hello all.
i'm Wesley from the Netherland (that's the reason of my probaly bad English).
I have an PA amplifier from the around 90's, the issue/problem is that the trafo is buzzing (idk if that is the right word?).
If i turn on the amp with no speakers connected or with that doesn't mather for the issue there start something buzzing i think its the ringtrafo.
And if it is the ringtrafo can it be fatal for the amp because make's a lot of noise, or is the trafo worn?
I hope someone has an answer on this forum.
Greetings Wesley.

I also don't now if ringtrafo is English, if not it's an round trafo in the center of the amp in the attachmend is an picture of it.

 

I would say that your toroid transformer is buzzing because of excess current draw. Probably because an output transistor or two have shorted.

 

I would say that your toroid transformer is buzzing because of excess current draw. Probably because an output transistor or two have shorted.

Ok i have read something already some where.
It's only a bit dificult to see it in the amp.

 

The "ringtrafo" as you call it, is a transformer or inductor wound on a toroid.

https://en.wikipedia.org/wiki/Toroidal_inductors_and_transformers

It would be easier to diagnose if I was there and could hear what you are hearing. That said, you need to probe with a non-conducting probe an proper eye protection just what exactly is making the noise. Can you measure the current draw of the device at any point?

Good Luck

 

Hello,

As @SLK001 sais, there will be a high current drawn from the transformer.
Check the transistors and capacitors.

Bertus

PS if you want to ask your question in dutch, you could ask Mat at http://www.elektronicaforum.nl/

 

Hello,

As @SLK001 sais, there will be a high current drawn from the transformer.
Check the transistors and capacitors.

Bertus

PS if you want to ask your question in dutch, you could ask Mat at http://www.elektronicaforum.nl/

bertus: Haha thank you for the link are you dutch? (volgens mij wel?)
papabravo: i'm gonna look at it if i have time.

 

Hello,

Yes, I am a moderator at the mentioned forum.
I am from Amsterdam and almost 8 years active in this forum.

Bertus

 

Hello,

Yes, I am a moderator at the mentioned forum.
I am from Amsterdam and almost 8 years active in this forum.

Bertus

haha ok.

 

Another possibility is that the bolt holding it to the chassis has come loose.

 

Another possibility is that the bolt holding it to the chassis has come loose.

so if i will screw is stronger it can be over or less noisy?

 

Don't tighten it too much, but if it is loose then, yes, tighten it up a bit.

 

Don't tighten it too much, but if it is loose then, yes, tighten it up a bit.

i wil try to thighten with an litle bit of force to it.
How tight are those normaly screwd in?

 

The previously mentioned capacitors are notorious for deterioration with age. In particular, the electrolytic type will often become defective over the years. Typically, electrolytic capacitors are round, cylindrical, and sometimes referred to as 'can' shaped. You might do well to simply pick out these capacitors in your amplifier and replace them. If they are not currently defective, they have already seen a useful life span.

e.g ... The four black can shaped parts in your photograph.

 

The previously mentioned capacitors are notorious for deterioration with age. In particular, the electrolytic type will often become defective over the years. Typically, electrolytic capacitors are round, cylindrical, and sometimes referred to as 'can' shaped. You might do well to simply pick out these capacitors in your amplifier and replace them. If they are not currently defective, they have already seen a useful life span.

haha after around let's say 18 years it of course can be done with his life if not the are strong capicitors.

 

The previously mentioned capacitors are notorious for deterioration with age.

I have a 1955 valve radio with its original electrolytic capacitors in it and it still works just fine

 

I have a 1955 valve radio with its original electrolytic capacitors in it and it still works just fine

wow they have a long live time i think then i hope mine are still good as well then.