Fighting ground buzz when trying to split signal

FastRedPonyCar

FastRedPonyCar

Member
OK here's the dilemma. I have my acoustic going into literally any effects processor and then out to a ditto X4 looper. I need to send that looped signal out to a monitor and to a PA but right now testing this, I can only get it to one or the other without introducing a loud buzzing sound.

If I try to send out of the second output of the looper, I get a buzz.

If I try to send out of a Radial bigshot AYB box, I get a totally silent signal out of one OR the other but the minute I hook up a second cable to either output jack, I immediately get the buzzing.

I've tried just plugging into a Helix LT and one output to a monitor (again, totally silent) but then a second cable out of the other main output or heapdphone output and immediately get the buzzing sound again.

The problem is that the PA cannot send to a monitor. It's a simple rig (not mine) that only sends out to a pair of mains so I have to split my signal down to my monitor.

I've ordered a Lehle Little Dual amp switcher that is active and has a transformer in it that they CLAIM eliminates the buzzing but will this actually fix the problem?

I've tried splitting this signal from a helix LT floor unit, a stomp HX unit, my Kemper and just straight into the looper and out to both PA and monitor and no matter what device I'm going to, the minute I try to split it to the second destination (pa or monitor) the buzz is introduced.

The bigshot's ground lift and iso switch don't fix the problem either.

I guess my main question is what is actually causing this problem in the first place? I've tried plugging both the PA and the floor monitor into a furman PL-Plus power conditioner to try and clean up the power if that was the culprit but no luck there either.

So the end result I need is this:

Acoustic guitar -> effects unit -> Looper -> Split to PA and Monitor
 
With ground loop you need to start simple and build up the rig until ground loop is present to know what’s causing it. Disconnect all effects and start there.

The concept with proper ground hum elimination is to have things ground referenced individually so that they don’t cause an issue and using balanced lines to connect gear so that it becomes a non issue. When you start connecting ground referenced gear with unbalanced mono or stereo connectors, you begin linking grounds of one unit to another. Technically you could use buffers to accomplish your goal but one thing should remain clear - all individual units should always remain grounded for safety. No breaking off ground plugs.

So start small. Check all cables. Keep track of what is grounded and when you’re connecting something, whether it makes sense to lift the ground of your signal line to that unit.
 
Everything powered is coming from the same outlet - the power conditioner? Yes?

You have engaged the ground switch in your Helix LT at the back? XLR outs? Sometimes these ground switches only apply to some of the connections and not others.
 
TheToneDig said:
Everything powered is coming from the same outlet - the power conditioner? Yes?

You have engaged the ground switch in your Helix LT at the back? XLR outs? Sometimes these ground switches only apply to some of the connections and not others.
Click to expand...
Yeah everything is coming from the furman. I've tried the ground switch on the helix with no change in sound. Also, it is not limited to the helix. I can literally just plug the guitar into the ditto and then try to connect the left and right outputs and still get the buzz.

I can run one output from the ditto to either destination and have complete silence but the minute the jack going to the second destination touches the other output jack of the datto, it buzzes.

This behavior is identical when connecting the second destination to the kemper, the helix, the radial bigshot and the stomp HX. Every single device does this.
glpg80 said:
With ground loop you need to start simple and build up the rig until ground loop is present to know what’s causing it. Disconnect all effects and start there.

The concept with proper ground hum elimination is to have things ground referenced individually so that they don’t cause an issue and using balanced lines to connect gear so that it becomes a non issue. When you start connecting ground referenced gear with unbalanced mono or stereo connectors, you begin linking grounds of one unit to another. Technically you could use buffers to accomplish your goal but one thing should remain clear - all individual units should always remain grounded for safety. No breaking off ground plugs.

So start small. Check all cables. Keep track of what is grounded and when you’re connecting something, whether it makes sense to lift the ground of your signal line to that unit.
Click to expand...
See my reply to ToneDig. I also tried just plugging the guitar into the radial AYB box and I can have total silence to either destination by clicking the switch to only send signal to A or B destination but when I enable both A and B, I get ground hum from both the monitor and the PA.

The ditto outputs are TS 1/4" and that is the last pedal in the chain and has to come before any effects processor so that if I have a loop going, I don't want effects to be applied to my loop, hence it coming after any effects processor.
 
You can try that switch you are getting or buy a dedicated hum eliminator pedal. I would try to solve this at the source though as much as I could before resorting to that. However, those pedals and racks dedicated to hum elimination do what you want.
 
I think my main problem is that I don't know where the hum or buzzing is actually coming from because it happens with every device and it happens in my studio and at the bar I played at this weekend. I've tried using two different furman PL-Plus conditioners at both locations too so I'm just sort of grasping at straws.

As much as I would love to understand what exactly is the culprit, a band-aid solution with an isolator/splitter seems like the only (hopefully immediate) quick fix. Assuming it fixes it, I can live with that.
 
Hey Drew. Long time no see :D

Looks like you are trying all the right things. I hope you don't have to go as far as an isolation transformer. Also, did you already get the ABY box? Def sounds like a group loop issue.

I fought with this problem for months before I finally was able to remove all the crap in my head and simplify the problem. I tried different outlets, different tubes, different cables, different positions, different everything.

You know what fixed it? A $3 ground lift plug like below. For one side of the equation, not the entire rig. Use your best piece of gear with the best grounding as the ground for everything basically - so that unit will NOT have the ground lift, only the other one.

Also, sometimes I refer to this when I need some sanity. Good luck,
https://www.psaudio.com/ps-how/how-to-find-and-fix-hum/
 

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Radial shotgun for the win

Such a good little piece of gear, i own 3

One to split up front to all amps and buffer the signal pre fm3. Their buffer is awesome!

One before or in my jd6 to split again before the wet amps

And one for my main:target amps in between or if i want main to 3 target (slave) amps

Best piece of utility gear i own
Its not footswitchable, just turn off the gear u aint using, footswitch spitters don't ever sound right anyways to me.

Made in Canada
$150 for the win
3 splits, one tuner out (unaffected), one thru
Needs power
 
And it sounds like you actually have a legit, not "I think the internet says its a" ground issue

Like a ground wire in the pa is off or the switch? Somethings amis.. the radial aby is dead silent too.
 
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