Ground Loop issue/question with footswitch.. Splawn Nitro

Bash_Man

Bash_Man

Well-known member
hey everyone,
so the other day I plugged into my Nitro.. just guitar right into Nitro and just the footswitch.

When I was switching channels on the nitro, I noticed there's switching pop coming through the amp.

Any ideas what could be causing that?

Thanks
 
A few things you can try... does it keep happening after several toggles of the switches? If not (just happens a few times) it could be some capacitance that has built up and discharges when you toggle the switch.

You could spray the pinned connector with contact cleaner and plug it into the back of the footswitch a few times to try to get any gunk cleaned out which can always cause noise issues. Could try the same thing with the 1/4" jacks into the back of the amp (while the amp is off!)

Finally, on the footswitch, make sure the screws are tight that hold the pinned connector down. I had noise problems with my footswitch and I took it apart and tightened the jack up and it helped a lot.

Good luck!
 
cvogue said:
A few things you can try... does it keep happening after several toggles of the switches? If not (just happens a few times) it could be some capacitance that has built up and discharges when you toggle the switch.

You could spray the pinned connector with contact cleaner and plug it into the back of the footswitch a few times to try to get any gunk cleaned out which can always cause noise issues. Could try the same thing with the 1/4" jacks into the back of the amp (while the amp is off!)

Finally, on the footswitch, make sure the screws are tight that hold the pinned connector down. I had noise problems with my footswitch and I took it apart and tightened the jack up and it helped a lot.

Good luck!
Click to expand...
Thank you. I'll try your suggestions next weekend when I am jamming on the amp.
 
Hey cvogue,
I tried the contact cleaner and it didn't do anything unfortunately. the noise and pretty much anything related to the ground loop seems to be coming from the effects loop. Even if nothing is plugged in.

I made a video to demonstrate the noise coming even when there's nothing in the loop:


Gonna contact Scott at Splawn and see what he has to say.

Thanks
 
Bash_Man said:
Hey cvogue,
I tried the contact cleaner and it didn't do anything unfortunately. the noise and pretty much anything related to the ground loop seems to be coming from the effects loop. Even if nothing is plugged in.

I made a video to demonstrate the noise coming even when there's nothing in the loop:


Gonna contact Scott at Splawn and see what he has to say.

Thanks
Click to expand...

Ahh, bummer, yeah if there's nothing in the loop it should be quiet as a mouse... even if something *is* in the loop (and off) it should be quiet.

Sorry couldn't help more, yeah let Scott know. Good luck man.
 
Thanks Buddy.

Can anyone else with a Nitro test this out for me see if they experience the same thing?

Thanks
 
OK, one thing I noticed, and I haven't done this, your loop volume is *cranked*. Is the hum consistent with different loop volume levels or does it vary when you turn it down.

I'll try this on my Street Rod at practice on Wednesday.

Not that it should matter, loop should be quiet when nothing is in it I'd think, but it may be a useful data point.
 
cvogue said:
OK, one thing I noticed, and I haven't done this, your loop volume is *cranked*. Is the hum consistent with different loop volume levels or does it vary when you turn it down.

I'll try this on my Street Rod at practice on Wednesday.

Not that it should matter, loop should be quiet when nothing is in it I'd think, but it may be a useful data point.
Click to expand...
Loop volume isn't cranked actually. its about between 3 o'clock and 4 o'clock. Never tried to change the volume and see if the issue persists.
 
cvogue said:
That's still

That's still really high, shouldn't hum, but it is high.
Click to expand...
The model I have is 1st gen Nitro from 2007 or 2008. The loop in there is a replacement circuit that Scott Sent me. I've had this issue since the original loop. Hence why the replacement.

With the Loop volume, with the original circuit there was no volume, so wouldn't that mean that the loop volume was always cranked?. just curious.
 
Bash_Man said:
The model I have is 1st gen Nitro from 2007 or 2008. The loop in there is a replacement circuit that Scott Sent me. I've had this issue since the original loop. Hence why the replacement.

With the Loop volume, with the original circuit there was no volume, so wouldn't that mean that the loop volume was always cranked?. just curious.
Click to expand...
Yeah that sounds right, the loop volume is really just attenuation I think. Scott may have put some additional mojo in there but with no volume I'm pretty sure you get the full blast of Splawn majesty! (Which can level small buildings even with my 40 watt Street Rod... loop volume was a great idea)
 
cvogue said:
Yeah that sounds right, the loop volume is really just attenuation I think. Scott may have put some additional mojo in there but with no volume I'm pretty sure you get the full blast of Splawn majesty! (Which can level small buildings even with my 40 watt Street Rod... loop volume was a great idea)
Click to expand...
I emailed Scott and sent him the same video link. Let's see what he has to say.

thanks
 
Loop has a poor ground?
What happens if you put a small patch cable in?
What do you see if you put a GFI tester in outlet (everyone needs one of these)?
What happens if you plug into a ground lift plug at outlet?
 
311splawndude said:
Loop has a poor ground?
What happens if you put a small patch cable in?
What do you see if you put a GFI tester in outlet (everyone needs one of these)?
What happens if you plug into a ground lift plug at outlet?
Click to expand...
Thank you for the suggestions. To answer your questions:
  • Loop has a poor ground?
    • that's what I am not sure about. Hoping Scott can tell me. Is there anything I can do to test that out or find out?
  • What happens if you put a small patch cable in?
    • same results even if its just a patch cord between the Send/Return. Hum comes ON when I engage the loop
  • what do you see if you put a GFI tester in outlet?
    • everything checks out for wiring. Proper Ground, etc..
  • what happens if you plug into a ground lift plug at outlet?
    • I don't have one of those, but I do have and did try with one of those EBtech Hum X plugs. No difference.

Thanks
 
I just realized you are 'Duke of Metal' LOL. I thought you were new here :D

Just a few other observations or ideas.

Number 1 - I don't think the hum is all that bad. I mean my QR hums like that as I think most amps do. When you were switching it on and off it reminded me of switching a Noise Gate on and off.

Also, this isn't really Nitro specific so to get more feedback, maybe post this in the main forum where you will get more eyes (or ears) on it.

So this is the second loop now? The first one did the same thing? And Scott deemed it defective? Or did he just send it to you try out? Was that under warranty? Did you do the work yourself? I am assuming the loop circuit has a ground connection/connector?

I'm not an amp tech nor have an electrical background. Just thinking of things I would do if it were my amp.

What happens if the guitar is plugged in?
Playing notes - with and without?
Have you tried plugging guitar straight into Effects Return?
Have you tried running Effects Send into another amp?

Honestly - I don't think it is that big of a deal. Maybe I'm missing something though. :dunno:

Good luck
 
311splawndude said:
I just realized you are 'Duke of Metal' LOL. I thought you were new here :D

Just a few other observations or ideas.

Number 1 - I don't think the hum is all that bad. I mean my QR hums like that as I think most amps do. When you were switching it on and off it reminded me of switching a Noise Gate on and off.

Also, this isn't really Nitro specific so to get more feedback, maybe post this in the main forum where you will get more eyes (or ears) on it.

So this is the second loop now? The first one did the same thing? And Scott deemed it defective? Or did he just send it to you try out? Was that under warranty? Did you do the work yourself? I am assuming the loop circuit has a ground connection/connector?

I'm not an amp tech nor have an electrical background. Just thinking of things I would do if it were my amp.

What happens if the guitar is plugged in?
Playing notes - with and without?
Have you tried plugging guitar straight into Effects Return?
Have you tried running Effects Send into another amp?

Honestly - I don't think it is that big of a deal. Maybe I'm missing something though. :dunno:

Good luck
Click to expand...
Yes, "Duke of Metal" is gone. Going under a new name. fresh start. LOL

The Hum isnt terrible, but to be honest, I dont think its something that should be there. Its not there when the Loop is disengaged. Scott said he couldnt really tell me over email and advised the amp tech I am taking it to to have a look at the loop circuit.

The replacement he sent me I soldered my self. I am confident in my soldering skills. It was only 2 wires anyways.

in the video I posted, the guitar is plugged in. Hum continues even if guitar isnt plugged in. The hum remains even if I play any notes. I have not tried plugging the guitar into the loop return, however the hum is there even if no guitar is pluged into the amp or if anything is plugged into the loop.

The hum comes when the loop is activated via the button.

At the end of the day, its not a huge huge deal for me, however it'd be nice to get it fixed to reduce the overall noise even more.

I am bringing it to an amp tech next weekend to have this issue looked into and have other mods installed as well (Bias point, channel switching without footswitch and 9V outlet jack on back).

Cheers
 
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