Strymon Mobius (anyone try this)

Hey Tim,
Have you actually experienced ground loops with your set up? I run my mobius pre/post, I have an h9 but I don't use it pre/post. But i haven't had any issues with any ground loops.

I'm in the middle of the pedal board build. I'm actually attempting to avoid ground loops before they happen and it's become quite clear that ground loops will occur in the "Output 2" of both, the Mobius and H9 units when running Pre / Post. In the video by Pete Thorn (mentioned above), he makes it quite clear that ground loops are going to occur when running Pre (front of amp) / Post (FX Loop). My board is quite complex and large with insert and exit points that I really don't want to have to re-cable after everything is in place (way too many cables to deal with). What I've decided to do at this stage is to finish-up the "Pre" path (all FX in front of the amp) and then thoroughly test for any issues and then move on to the "Post" (all FX in the FX Loop) connections (even though I've already run the cables from the PBC to the "Post" pedal locations. When I get to the "Post" pedals, then I'll connect each pedal one by one and test the entire board until I'm satisfied, and then move on to the next pedal / then test. I still believe I'm going to need a Radial Stagebug SB-6 on the "Output 2" of the previously mentioned pedals. But, I'll address that issue when I get to it. Again, just trying tackle all the potential problems before they happen. I've contacted Radial and their Rep assured me the Stagebug SB-6 can handle both FX pedals "Output 2" ... he states that each channel is independent.
 

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Soory I didn't see this yesterday, but it's good that you went with the Radial box - the box you made is grounding all the jacks together through the box. In a box like that, I'd only use Neutrik's nylon jacks, because only then would you be sure that the jacks wouldn't have their grounds shorted together.
 
Soory I didn't see this yesterday, but it's good that you went with the Radial box - the box you made is grounding all the jacks together through the box. In a box like that, I'd only use Neutrik's nylon jacks, because only then would you be sure that the jacks wouldn't have their grounds shorted together.

Thanks for the input ... I thought that was what was happening with the box I made (grounding). I'll look for the Neutrik nylon jacks next time I have a brainstorm for a fix. Really good input, thanks.

When this board is finished I'll post photos out here with all the cable routing, signal path, along with my original "design concept drawings. Also, I'll include all the pitfalls I've encountered in the DIY process. Maybe it'll help others in their quest. I've built my own home and I thought it was time for me to build my own pedal board ... whew, what a daunting task to get it right. Every addition adds complexity ... but, in the end it's going to be cool. I will not quit until it's right.

With the capabilities of the Mastermind PBC (I must keep on point here) ... it's amazing how many options there are. I started out following Pete Thorn's pedalboard signal flow (on Strymon's website ... also watch his PBC video) and used it as a guide to get to where I wanted. I first viewed the PBC on Sweetwater and their demo never even came close to scratching the surface of it's complexity. Then, finally I watched Ruben Roeh's video (he's added a post on this thread) ... amazing piece of gear and what a wealth of information hes provided. Anybody who has not watched that video and owns a PBC, should ... get a soft drink and some lunch and pay attention. Thanks Ruben.
 
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Just ordered a Radial Stagebug SB-6 (new for $79.00) ... Here's my plan (attached). This will give me a total of 4 isolation transformers on the board ... 1 on the PBC, 1 on the Y-Not (underneath board), and 2 on the Stagebug SB-6 (underneath board) ... this should handle any potential ground loop issues ... but, we'll see!
 

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Firstly, I've watched Ruben's video SEVERAL times too. Thanks Ruben it is a fantadtic insight into just how powerful the PBC!

I dont know if I'm misinterpreting your post or not.

Are you worried about ground loops because of the combination of Mobius and H9 both running in Pre/Post configuration or just Pre/Post on either unit?

I've recently finished building my board which includes Mobius pre in loop 5 and Mobius post in loop 8. It also has insertpoints on the board (Neutrik locking jacks) for out 1-4, In 5-6 (currently bridged as the first 6 loops are all running in front of the amp. Out 5-6 runs to the input of my Boogie Triaxis (or Dual Rectifier for mono setup). The FX send of from the Boogie plugs back into In 7-10 on my board. Amp A goes to FX return A on the Triaxis and Amp B goes to FX return B on Triaxis (Timeline and TC HoF are running in stereo in loops 9 & 10 set to parallel). I'm running Ron's cable specs as per the stereo pedals blog post.

Even on really high gain setting I don't have any ground loop issues. Everything sounds spot on. I would be very surprised if Strymon hadnt already thought about ground loop issues and designed the pedal accordingly. I would assume the two signal paths are already isolated within the Mobius itself.
 
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Firstly, I've watched Ruben's video SEVERAL times too. Thanks Ruben it is a fantadtic insight into just how powerful the PBC!

I dont know if I'm misinterpreting your post or not.

Are you worried about ground loops because of the combination of Mobius and H9 both running in Pre/Post configuration or just Pre/Post on either unit?

I've recently finished building my board which includes Mobius pre in loop 5 and Mobius post in loop 8. It also has insertpoints on the board (Neutrik locking jacks) for out 1-4, In 5-6 (currently bridged as the first 6 loops are all running in front of the amp. Out 5-6 runs to the input of my Boogie Triaxis (or Dual Rectifier for mono setup). The FX send of from the Boogie plugs back into In 7-10 on my board. Amp A goes to FX return A on the Triaxis and Amp B goes to FX return B on Triaxis (Timeline and TC HoF are running in stereo in loops 9 & 10 set to parallel). I'm running Ron's cable specs as per the stereo pedals blog post.

Even on really high gain setting I don't have any ground loop issues. Everything sounds spot on. I would be very surprised if Strymon hadnt already thought about ground loop issues and designed the pedal accordingly. I would assume the two signal paths are already isolated within the Mobius itself.

I'm worried specifically about ground loops running Pre/Post on either unit.

I hadn't even considered this issue prior to hearing Pete Thorn's QnA#25 regarding 4-cable boxes and more specifically the H9 and Mobius with regard to Pre/Post operations. I've got my board cabled-up for both units (need Jacks at the fx end still) ... then I heard the video and decided it would be the appropriate time to address any potential ground loops and nip-it-in-the-bud. This is a 100% DIY board and that's where the overly cautiousness comes from.

Attached, is my design plan that I'm following.

Thanks for your input ... any and all input is greatly appreciated.

I tried to upload an mp3 of the specific excerpt from Pete Thorn's video ... I guess we can't do that on this forum. Let me know if we can add mp3 audio files to our thread and I'll follow-up with an upload.
 

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I'm worried specifically about ground loops running Pre/Post on either unit.

I hadn't even considered this issue prior to hearing Pete Thorn's QnA#25 regarding 4-cable boxes and more specifically the H9 and Mobius with regard to Pre/Post operations. I've got my board cabled-up for both units (need Jacks at the fx end still) ... then I heard the video and decided it would be the appropriate time to address any potential ground loops and nip-it-in-the-bud. This is a 100% DIY board and that's where the overly cautiousness comes from.

Attached, is my design plan that I'm following.

Thanks for your input ... any and all input is greatly appreciated.

I tried to upload an mp3 of the specific excerpt from Pete Thorn's video ... I guess we can't do that on this forum. Let me know if we can add mp3 audio files to our thread and I'll follow-up with an upload.


Nice Board Tim.

I just watched Pete Thorn's video. The problem the guy was talking about was hiss rather than buzz and Pete just started talking about ground loops in 4 cable in general rather than specifically with pre/post in mobius or H9. I think the issue is more likely to be caused by using two amps without an ISO transformer than using a pre/post path in with the pedals. Fortunately the PBC already has an ISO transformer anyway.

Just checked my own set up (100% DIY board too) and I do have a bit of noise and tone suck even with all pedals out the loops. I'm pretty sure its not ground loop from the pre post pedals though as it is still there when I unplug one side of the Mobius. Guess I have some more cable testing still to do :-(
 
Just spent a few hours playing with my board and amp. The slight buzz I mentioned is only in the Triaxis Ld2 modes which are the really high gain channels. However, it is still there (unchanged) even when I completely unplug the whole pedal board and just plug the guitar straight into the front of the amp. Certainly doesn't seem to be any ground loop issue on my board from running pre/post on my mobius.
 
Nice Board Tim.

I just watched Pete Thorn's video. The problem the guy was talking about was hiss rather than buzz and Pete just started talking about ground loops in 4 cable in general rather than specifically with pre/post in mobius or H9. I think the issue is more likely to be caused by using two amps without an ISO transformer than using a pre/post path in with the pedals. Fortunately the PBC already has an ISO transformer anyway.

Just checked my own set up (100% DIY board too) and I do have a bit of noise and tone suck even with all pedals out the loops. I'm pretty sure its not ground loop from the pre post pedals though as it is still there when I unplug one side of the Mobius. Guess I have some more cable testing still to do :-(

Thanks for the compliment ... it's good to know other folks are attempting this daunting DIY project. It's so funny how we guitar players need to have "it" perfect ... I love my OCD. Hope you find your problem ... fast!

I was looking at my plan and if you studied it I'm sure you're wondering what the Black Box in the upper right corner is ... really no mystery, it's just a toggle switch for the power to my Hartman Vintage Germanium Booster ... I prefer to use cabon zinc 9v batteries and I didn't want to have to lift the pedal to change the battery when it needed to be changed. All I have to do now is unscrew the box and put another one in.

I may have a couple of questions to run by you, once I get to debugging the board.
 
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Hi Tim

I emailed Strymon about some other stuff the other day so I asked them about the ground loop issue at the same time. Hugo at Strymon said,

".....not everyone has run into ground loop issues when using the Mobius in pre/post functionality. This would be due to how the gear in the signal chain is grounded and would only appear if there are additional ground connections in the setup."

I take it from this that the Pre and Post paths are isolated from each other so there shouldn't be any ground loop issues if everything else is wired up properly but there is always the chance of something else causing the problem. I don't know enough to know whether your solution would work in this case but I'm sure Ron or someone more knowledgeable than me will know.
 
Hi Tim

I emailed Strymon about some other stuff the other day so I asked them about the ground loop issue at the same time. Hugo at Strymon said,

".....not everyone has run into ground loop issues when using the Mobius in pre/post functionality. This would be due to how the gear in the signal chain is grounded and would only appear if there are additional ground connections in the setup."

I take it from this that the Pre and Post paths are isolated from each other so there shouldn't be any ground loop issues if everything else is wired up properly but there is always the chance of something else causing the problem. I don't know enough to know whether your solution would work in this case but I'm sure Ron or someone more knowledgeable than me will know.

Thanks so much for doing that ... Now, I'm thinking that maybe I should just continue cabling as is without putting the Stagebug SB-6 in the mix (I have a location reserved underneath where it can fit, should I need it). If I do it this way, then I'll know whether I have a ground loop or not. If I connect the SB-6 now, I'll never know whether there was a ground loop. I'll keep my cabling somewhat loose, just in case ... at least until I'm done testing.

Again, thanks for all the great feedback ... really, really appreciated.
 
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No problem.

I think that's what I would do to. No point in adding the Stagebug if it isn't needed but if you leave space for it underneath the board it should be easy to add later if required.
 
Hi there, I just did a demo of my board doing this.

Great demo ... I can't believe how closely my new pedal board is going mirror yours (almost). I put a whole lot of thought (a couple of years worth) into the signal path, exit and entry points ... so, I can really appreciate what you've got going on here! Great job. I'll be browsing this video many times. When I saw the notification that you had posted to this thread, I was right in the middle of soldering my MIDI cables ... but, I had to stop to watch the video ... really, really inspiring. Thanks for posting this demo.
 
I just did a board using the pre/post feature and wanted to have both in loops but came up 1 loop short. So I kept the post section in a loop and inserted the pre section in between loop 4 and 5. Worked flawlessly. To engage the pre section, I send the corresponding midi CC as a preset action, and to engage the post section I do that plus turning the loop in question on.

Ruben,
I have mine wired exactly like this. However, i already have several hundred presets. Im finding i have to add a preset action to every preset in the library so that the mobius knows its bypass state. Is there a better way? I also added an IA to the "post" loop that toggles the bypass on the mobius so no matter what, i still reach for the same button to modulate.
Thanks,

John
 
Guys you have have just made my life so much easier!!!

I have Mobius in loop 5 (pre) and loop 8 (post).

I have a button page set up that lets me scroll through presets on all my midi pedals (timeline, mobius and the Triaxis Preamp) and save these to PBC presets. This page also has two IA buttons set up to scroll trough 4 presets on the Whammy and 4 presets on the DT side of the whammy pedal because of Digitech's ridiculous stupid midi implementation.

Up until now if I scrolled to a Mobius patch that was set as pre but I engaged loop 8 I got no effect.

I have just added a CC toggle to the loop on/off buttons which also sends the correct pre/post command to Mobius when the loop is engaged. I.E every time I engage loop 5 it sends a "Pre" command CC 22 value 0 to Mobius and every time I select Loop 8 it also sends a "Post" command CC22 value 1. Both buttons are part of a button group as Mobius can't operate in both pre and post states simultaneously.

So simple and blindingly obvious I can't believe I never spotted it until I saw John's post today!

Thanks John.
 
OK, I might have spoken too soon :-(

While it works perfectly when scrolling through presets or manually selecting a loop from the loop page Presets don't send the CC message. Is there an option I need to select that would ensure the correct pre/post status is active when a preset is loaded?
 
OK, I might have spoken too soon :-(

While it works perfectly when scrolling through presets or manually selecting a loop from the loop page Presets don't send the CC message. Is there an option I need to select that would ensure the correct pre/post status is active when a preset is loaded?

Make sure "Send CCs on Preset Change" is enabled for the Mobius on the Devices page. Also, the button needs to have Send on Preset Change and Update on Preset Change turned on.
 
OK, I might have spoken too soon :-(

While it works perfectly when scrolling through presets or manually selecting a loop from the loop page Presets don't send the CC message. Is there an option I need to select that would ensure the correct pre/post status is active when a preset is loaded?


This is essentially what i have run into as well. I think my fix is to add a preset action on the preset page for each preset that uses the mobius that just toggles it in and out of bypass. In your case, since its in two actual loops, you could just toggle the pre/post state as a preset action per patch right?
 
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