buzzing from amp head when cab in iso booth

[jononz]

Hi

I have a mesa boogie single rectifier and have just been messing around with recording it, with the cabinet isolated in an isolation booth. When the amp is cranked, there is a high pitched buzzing that comes from the amp that relates to the signal from the guitar. It seems to be coming from the output transformer. Is this normal? It is only really noticeable on the distorted channel. The level of the buzzing relates to the level of the amp - its only there when the amp is turned right up. I have replaced all of the tubes and it made no difference.

Jono

 

[Andy Sneap]

its normal.

 

[Aaron Smith]

Good to know. I noticed that my 5150 makes noise kind of like this as well, when I have my speaker cab in another room and the head in the control room. I never was really worried by it though, because it seemed to me that the noise was probably always there but of course you would never know it when the cab is blasting in the same room!

 

[jononz]

thanks for the quick reply

 

[greyskull]

its le valves isnt it? yeah yur heads fine, you just never heard this noise before

 

[GuitarHack]

I think it is the laminated plates of the output tranny vibrating together. Don't worry, in time the noise will only get worse (but wont cause any problems) as the glue between the plates dries up more due to the heat in the tranny and the laminations separate some more.

Maybe.