Calling RG for Alembic F-2B problem

[fikri]

I have built an Alembic F-2b Tube preamp (later i mod it into a D*umble). All control is working except one thing : I have a lot hums coming out as i turn up the bass pot. I have shield the input wire, rework the star grounding, and DC the fillament, but still i get this humm coming out. 

Could you help me please  ?

[moosapotamus]

What is your power supply like, B+, transformer, etc...?

How are you going to mod it into a D*mble?

~ Charlie