Can't get rid of ground loop clicks!

Hi everyone,

I’m looking for some help solving a problem with midi signals bleeding into audio, I’m sure the culprit is a Jackson Audio Asabi overdrive pedal but I can’t figure out how to fix it.

I am using an MC8 with a Lehle dual expression pedal, 2 ML10x’s, a Morningstar midi box, and my midi capable peals are the Asabi, Strymon Timeline, Source Audio EQ2, and Chase Bliss Habit. And a Rockboard patchbay with a CME WIDI Jack is part of the midi setup too.

I initially had everything chained in a loop (except the Asabi and Habit which use TRS midi) but was getting loud clicks when pressing buttons on the MC8 or using the expression pedal. I did a bit of research and solved the problem by getting the midi box and taking the timeline out of that loop. I could still hear the midi bleeding through but it was much quieter and more like a soft creaking, not much of an issue.

Later I tried using the expression pedal with the Asabi (overdrive) on and it immediately jacked up the volume of the clicking to an unusable level. After jumping through hoops switching the jumpers around in the midi box (Jackson Audio website still says their pedals use the ring), I can’t find any solution. The clicking is a little louder if the Asabi is plugged in to the midi box so that hasn’t helped like it did with the Timeline.

I guess I’m wondering, is it theoretically possible to have zero midi bleed into the audio at all? Even with the Asabi removed from the board completely, the other pedals bleed just a little bit.

I’m also wondering if there is a general best practice when connecting lots of midi devices? Especially with the ML10X’s, is it better to have a loop of devices using thru ports or just have the MC8 connected to the midi box and everything else connect to that?

Thanks and sorry for the long post!

Try removing the MIDI TRS connection from the Habit and see if that resolves the issue?

Hi James, no that didn’t work. The Habit does increase the general noise floor a little bit when I plug in the TRS but nothing like the Asabi.

Is everything powered via daisy chain or are they on their own isolated power outputs? If they are daisy chained then that might be part of the problem.

Also, after which, you can try removing the MIDI connection from each device and testing to see when the noise stops.

Ok I was wondering if the power supply situation would make a difference. I do have an isolated power supply but some pedals are still daisy chained into it so I’ll swap some around and see if it helps, thanks.

Thanks for your advice James, giving the Asabi it’s own isolated power supply has entirely solved the problem. I still have a very low level of midi noise coming through which doesn’t really get in the way but I’ll still try to fix it with some more power supply juggling :slight_smile:

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I’ve always found daisy chaining pedals ultimately causes an issue somewhere down the line.

I have a similar problem with the Jackson Audio Broken Arrow, even with isolated power supply and careful separate of cables. It’s frustrating.

Damn, I’m just in the midst of entirely rewiring my board to try to fix it so I hope it’s not some kind of unsolvable Jackson pedal issue.

Isolated power and isolated midi is king.
Keep adding things till you get noise.
consider the midi leads, it’s really easy to keep reintroducing a problem if you have a pile of leads and one is NQR
Daisy chains work or they don’t, adding midi does seem to up the anti.
I find somethings will work in a group no issue and some won’t - power and midi
And if all else fails … it’s grounding… it’s so often grounding :roll_eyes:.

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Thanks man, I’ve just finished rewiring my board and think I’ve sorted it :slight_smile:

Did you find it?

Well, I thought I did. I had the problem before I plugged in any pedals, so just within a loop of an MC8>Morningstar Midi box>ML10X>ML10X>Rockboard Mod2>back to MC8.

Took the Rockboard patchbay out of the loop and no more noise. Thought that was obviously the issue but now I’ve added all the pedals back, and put the Rockboard back in the loop just to check, and still no noise!

So I’m not sure I worked out what the actual issue was but everything is much quieter and much neater now so I’m happy enough with that haha

Final update as I definitively found the issue, and felt like such a dumbass when I figured it out; I was powering a WIDI Jack from a usb port on the power supply. Guess I’ll have to have a battery pack for that one after all.

Some usb adaptors are noisy and others are clean. Try a few.

Everything works best when plugged into the same outlet.

So much better to find it than have it reappear at some inconvenient moment.