Hi everybody,
I’ve been trying to troubleshoot this noise for a few days and I’m at a loss about what is causing it. I’m trying to use Amp+Loadbox into one loop of the ML5 so that I can switch between that and a modeler (among other things).
Now the problem is that if I run the 5150+loadbox through the ML5 I get this unbearable noise:
The change in pitch is me moving the volume pot in the guitar. If I remove the ML5 of the equation the noise is gone. The ground lift in the DI box doesn’t help. Also to make things even more weird… it only happens with the 5150, I have a Marshall Origin 50H that works as expected in the same configuration.
I’ve isolated the issue to the combination of 5150+loadbox through the ML5. The signal chain to reproduce the problem is:
Guitar (PRS Custom 22) → ML5 in → 5150+loadbox in loop D (tried all of them) → ML5 out → Walrus Canvas DI → Apollo x4 line input
If I remove the ML5 from the same chain, or connect the return of the loadbox straight to the DI I get no noise. Everything is connected to the same powerstrip that connects to the wall, and I’ve tried the original PSU and a Strymon Zuma to power the ML5.
What kind of loadbox are you using? What’s the rating of the output you connect to the ML5? Sounds like the signal is way to hot. You might fry the ML5.
I’m using a Driftwood Reactive Loadbox. It has a line level output as far as I can tell… and the levels I see in the Apollo seem normal to me.
Also as I said above, the noise disappears if I remove the ML5 completely or connect the output of the loadbox straight into the DI instead of the ML5’s return.
It’s almost as if the ML5 is creating a ground loop when combined with this specific amp+loadbox but I don’t know how to go about fixing it.
Just to troubleshoot, if instead of using the ML5 Out, you use Send E to send the signal out (keep Loop E engaged for this), does this behaviour still occur?
Hey James, yeah! I tried that and it still happens. It only goes away with that chain if I remove the ML5 completely or plug the out of the loadbox directly to the DI instead of the Return E.
But I’ve been doing some more testing and I found that the Marshall also has the noise. It’s just a very high pitch and you have to add ridiculous amounts of gain for it to be a problem. So I put a reamp box between the loadbox out and the Return E and lifting the ground there makes the noise go away! And it also sounds better so it looks like this was there all along.
Now I need to figure out if I can mod the loadbox to add a ground lift switch. Worst case I can add a proper iso box there but I’d rather avoid adding more transformers to the signal chain…
I’m guessing that hacking a ground lift in some loops of the the ML5 is not possible/relevant, right?
Thanks for your help!
Yeah, its not possible to add a ground lift per loop but maybe you can try it on the cable itself? I’m not sure how well that will work (if you disconnect the sleeve on one end).
Combining effects with load boxes and any sort of amp switcher is a breeding ground for ground loops. The amp squeal you hear is definitely a ground loop and easily fixed.
I had many of these issues with all the loopers I have tried including the ML10X as soon as I introduced a load box signal.
You could also buy a small isolation transformer and put it under your pedalboard to isolate the signal from the load box before it hits the ML10X. This could be easier if you dont want to start messing with cables and solder.
I use the quite a few of the Lehl Iso transformer devices and they are quite small and wont colour the sound.
Thanks for sharing your experience with this! It’s my first time using load boxes and switchers like the ML5 and this had me scratching my head for several days
I managed to do a quick and dirty test modifying the cable as @james suggested and it worked like a charm.
When I get back from my trip I’ll try to modify the loadbox. There’s already a transformer in there and it’s probably very easy to add a switch with a proper ground lift.
Sorry for resurrecting an old thread but I’m having a similar issue with the ML5.
It doesn’t seem to like the Rockboard Mods. I’m using a Mod 2 and a TRS and both of them introduce a line noise when connected to a loop.
In bothe cases I’m using a mono cable on either side of the TRS connectors and it should just behave like a TS thru. Unfortunately that’s not the case here.
I’ve tried all of the Rockboard suggestiosn such attaching an IEC cable for true ground and changing out my cables. Nothing has worked so I’ve reverted to using it without either patch bay.
