How much hum is normal from a new tube amp

@elliottbnewcombjr  Yes I meant to say KT150, that's what I have.

I have rebiased all the tubes.The hum is present with the preamp off. I used the DB meter from my phone and tracked the loudest reading and it is coming from the back of the amp. I have also changed the power cable, and I just tried plugging it into a different socket. I checked the speaker cables. I have used all this equipment setup with different amps and they are dead silent. 

Now that I listen to it more, I think the sound is coming from the inside. I'm not very technical and I don't know what the implications of that are. The hum is consistent. It starts within 8 seconds and never wavers. I suppose sending it back is the best course. 

@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".

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

@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.

@larryi @femoore12 @facten @auroravengeance  and everyone that has chimed in

Yes, I think replacing it is the best idea. It has a great sound, I would keep it if the hum was minor but I feel like this is beyond that.

@auroravengeance 

How long have you owned the Lab12 Integre4 MKII. Im asking because i heard the the hum can develop later or if you have a slight hum it can get worse. 

@macg19 

The seller TMR has been great. They are going to take it back inspect and either repair , replace, or refund my choice. Which amp do you have? If I can ask.

@auroravengeance 

I really liked mine too, I sent it back today, I can tolerate a faint hum, but I think mine may have had a malfunction. The performance was not effected through. It still sounded fine. 

@macg19 That's pretty sweet looking, out of my budget though.

@ltmandella My hum is coming from inside the unit