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I have a medium sized pedal board, ~10 pedals. My previous incarnation was
Compressor -> Line6 M5 -> Chorus -> Digitech Drop -> Overdrive -> Distortion -> Echo -> Boost
I'm using an 8-output isolated PS plus an extra outboard One Spot, so the only ground connection between the pedals is the jumper wires (George L).
The board was fairly quiet, but as soon as I powered up the M5, the OD and Dist would hum like a bass kazoo. Power off the M5, quiet again. (The M5 was on it's own private supply, and I tried two different PS units, no difference). As an experiment, I took a jumper wire and connected various pedal grounds together. I discovered that if I connected the ground of one of the pedals near the input to the ground of one near the output, the hum decreased substantially. So, I'm basically /creating/ a ground loop (two paths for ground current) and it's a lot quieter. How would this happen?
The M5 has been getting flaky, so I removed it and added a Wah, tuner, and a MojoVibe. Although the monster hum from the M5 was gone, connecting the grounds with a jumper as described above still makes the hum from the dirt pedals noticeably quieter.
There is about 3 ohms of resistance between the input and output grounds, likely due to all the plug/jack connections.
Thoughts?
Compressor -> Line6 M5 -> Chorus -> Digitech Drop -> Overdrive -> Distortion -> Echo -> Boost
I'm using an 8-output isolated PS plus an extra outboard One Spot, so the only ground connection between the pedals is the jumper wires (George L).
The board was fairly quiet, but as soon as I powered up the M5, the OD and Dist would hum like a bass kazoo. Power off the M5, quiet again. (The M5 was on it's own private supply, and I tried two different PS units, no difference). As an experiment, I took a jumper wire and connected various pedal grounds together. I discovered that if I connected the ground of one of the pedals near the input to the ground of one near the output, the hum decreased substantially. So, I'm basically /creating/ a ground loop (two paths for ground current) and it's a lot quieter. How would this happen?
The M5 has been getting flaky, so I removed it and added a Wah, tuner, and a MojoVibe. Although the monster hum from the M5 was gone, connecting the grounds with a jumper as described above still makes the hum from the dirt pedals noticeably quieter.
There is about 3 ohms of resistance between the input and output grounds, likely due to all the plug/jack connections.
Thoughts?
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