How much hum is normal from a new tube amp


I just bought a great sounding Lab12 Suara KT120 tube amp. The issue I am having is a hum that is coming from the transformers. I can hear it with no music playing faintly from my listening position 12 ft. away. The question is, should I return it, or is this normal acceptable. 

blue-magoo

Yes a different chord and outlet. I have a Furman R8 strip. I haven't had any hum on previous tube amp.

@fractin

They will take it back but, I Love the amp. I guess my question should be if I get a replacement with the same amp will I have the same problem.

It has been suggested that this a an issue with KT150 amps in general.

I think I should pose the question on a new post. "How many have had hum issues with KT150 tube amps".

If the hum level changes from time to time, it may be from  DC offset in your power line caused by other things in your home contaminating your power.  You can try powering the amp from a different circuit using extension cords, or turning off each circuit until the hum stops.  Depending on when the offending equipment is in use, the hum level will change which may be an indication that the cause is in your power delivery to the amp.  Some transforms are more susceptible to this problem than others, which may account for why this is only happening to this amp.  Toroidal (round shaped) power transformers are more apt to hum from less than ideal power feed.  The problem with DC offset is that one cannot easily measure it to get a definitive diagnosis and most power conditioners don't deal with it. 

Another possibility is that the power transformer is overheating because of a problem in your amp or because the manufacturer put in one that is not up to the task.  Is the transformer hot to the touch or merely slightly warm?  If it is fairly hot, you should talk with the manufacturer even if you had decided you could live with the slight hum because there could be a bigger problem.    

@larryi 

I have decided that the sound may be coming from the inside rather that the transformers.  The hum is consistent. I have change power chords and used a different socket, though they may be connected. The transformers are slightly warm to touch and square in shape.  I do not think that this is a moderate hum. In a quiet room with only the amp on and no music, I can hear it from 25ft away. I would describe my heating to be good but not stellar.

That sounds like a fabrication defect. I would ask to exchange it for another one if you really enjoy the sound.