hum noise with rangemaster clone into a crybaby wah

[Silvio55]

I was playing at home today with my rangemaster clone and my pedalboard, in wich the first pedal is a Crybaby gcb95, non true bypass the wah was off and was getting some hum that didnīt have when used the rangemaster alone.
i tried putting the rangemaster in front of another pedal and it was quiet, the problem is when the crybaby is in the chain. Even tried the rangemaster without an input cable plugged in, so the battery gets disconected and guess what? Still hum!
My rangemaster is PNP germanium, TBP, powered with a battery and all my pedals are true bypass except the wah.
What's the problem with the Crybaby and the RM not getting alone, even when the RM has the battery disconected?

[mozwell]

Silvio
I am guessing its mains hum being picked up by the wah. The inductor inside the wire acts like an antenna & picks up the mains hum.
If your wah is battery powered, move it as far away from the mains wiring as you can, if the hum goes away the inductor in the wah will need to be shielded.

The guitarist in my band has a bad horsie 2 wah, and he has to move it several feet away from the 240V in his pedal board to stop it humming like crazy when its on.
I have some copper foil which i will use to see if i can get rid of the hum, havent got around to doing that as yet.

[Silvio55]

The hum only occurs when the RM is "on", not in bypass, even when there's nothing plugged in the input of the RM, so I don't think it's hum picked by the wah, otherwise it would hum no matter the RM switch position. Using the wah without the RM in front it doesn't hum.

[Mick Bailey]

How's your wah powered?

[Silvio55]

With a regulated and isolated power supply, it powers all my five pedals, except the RM that's powered with a battery.

[Silvio55]

Well, I found the problem, it was the lack of grounding, the outlets in my house don't have grounding, I use a cable attached to a bathroom pipe for grounding but it was disconected! Once I conected the ground, the hum desappeared.
But this led me to think; sometimes (most of the time really) when going to an indoor gig, the place doesn't have grounded outlets, I always bring a long cable for my ground, I just stick it with and old screwdriver to the ground, easy to do at an outdoors gig, but when is indoors, sometimes it's just impossible to do this, no ground near or not even a metal pipe to attach the cable, so this would make it impossible to use the RM with the wah.
I was thinking, if I make a negative ground Rangemaster with a NPN Ge transistor, would it hum less with an ungrounded line?