Hey all, I just finished a boothill 5f1 kit with a classictone 15w OT (http://www.classictone.net/40-18031.html). I’m having a hum that gets louder as I turn the volume up, no cable into the input. When a guitar cable is plugged in to either input the hum is almost gone but still thereat a much lower volume. Also, when I take the 12ax7 out the hum stops completely. I’ve also swapped tubes with the same result and checked my soldering so now I’m at a loss. I’m using the ground bus and attaching all preamp grounds to that. Could the hum be coming from a loop that is caused by the vol pot and/or switchcraft input jacks not being isolated? Here is the layout with the adjustments I made to compensate for the 15w OT. Thank you in advanced for any insight you might have.