I have a hum

[ranchak]

I just built a two channel version of the Real McTube. I made some changes from the original design. I used a 12v AC transformer to supply incoming AC voltage, the transformer is mounted outside of the stompbox. To step up the 12v AC I have a toriodal transformer located inside of my box. I kept the incoming AC, the toriodal and the rectifier/filtering stages at one end of the box. My problem is that I have a hum. I read that installing a 100ohm resistor between the heater pins to ground will help to remove hum. I don't know if this is something that I should try (since this isn't really an amp). I used RG174 cable and kept my wiring short, I have insulated input/output jacks. If I plug my guitar directly into my amp it's quiet, but I get that hum when putting this pedal in the signal. Any help would be appreciated, this is a great sounding pedal. I have some other tube pedals that I would like to build, but I need to get rid of this hum.

[sfx1999]

Is it hum or buzz?

Have you tried another tube?

[puretube]

schematic? (link)

[I was too lazy to go thru 17 pages of "search results"]