Electrical Interference w/ sound clip - please help?

Luke MacDonald · 08-27-2013, 07:33 AM

Hi,

I am getting some kind of electrical interference when going direct in with my guitar or bass. I am going through a DMP3 into a Line 6 gearbox DI. I tried plugging right into the gearbox, and also tried changing cords and instruments, and I still had the interference. I haven't recorded DI in a while, but this happened the last time I tried to as well. I was adjusting my bass intonation with a screwdriver, not sure if somehow this could cause something to go haywire?? It seems unlikely given that I changed instruments and cords and it was still doing it.

The interference comes and goes...it'll be there for 30-60 seconds then stop for a similar amount of time and start up again. Needless to say this makes it a little difficult to try and record.

If anyone could provide any help it would be greatly appreciated. The sound can be heard here (recorded while plugged into my bass):

https://soundcloud.com/fullflowering...erence/s-4O3Nj

Thank you,
Luke

Panic · 08-27-2013, 11:18 AM

are you talking about the morse code sounding buzz?

Luke MacDonald · 08-27-2013, 11:28 AM

What you hear in the sound clip, yeah.

Panic · 08-27-2013, 01:48 PM

No idea what is causing the pulsing in the pickup buzz, but the faint noise in the back ground sounds like low level voltage, looping internally through the ground and coming through in the audio.

ivansc · 08-27-2013, 02:15 PM

definitely mains-borne interference.

I assume you are on a laptop, which gives the possibility of a ground loop, but ground loops don't usually give this sort of intermittent modulated buzz.

My best guess is that you have a piece of electrical equipment on the same mains loop as your recording stuff which is causing it. A fridge, or A/C or even something as dumb as a wireless phone power supply!
If you run out of possible causes, the quickest and easiest way to take care of it is to connect everything to the mains via a 1:1 mains isolating transformer.

Luke MacDonald · 09-10-2013, 02:19 PM

"Mains" means wall power essentially right? I'm not sure if it's that. It's strange. I thought it was a bit of a fluke as I shut down and restarted my computer the other day and I was able to record bass fine. Then today it's doing it again. It seems to have something to do with my bass as far as I can tell right now. When I turn down the center pickup volume (it's a Yamaha RBX170), the sound seems to go away.

I'm going to have to see if I can figure anything more out...the thing is, when I was messing around last time it was doing this, the interference sound would continue when I would unplug my bass.

Is it possible that a pickup could cause some kind of loop that would then continue even when the instrument was no longer plugged in?

Dynsdale · 09-11-2013, 11:33 AM

The good new is that you didn't cause the noise by adjusting the intonation on your bass. In fact if the noise is still there with the bass(and of course its cable) unplugged you can eliminate the bass as the culprit. That leaves your computer, the pod,something connected to the same electrical circuit as your computer or something causing interference in the proximity of your setup.
Check the easy stuff first: do you have a fluorescent light nearby? Check for a/c, cable box, humidifier, phone chargers etc. Try plugging into a different outlet that's on a different circuit. Next update the driver for the pod(do you use the sound card in your computer while you record? If not turn it of as it might cause a conflict with the pods driver). Also check out this link for trouble shooting the pod:

http://line6.com/support/knowledgeba...eshooting.html

Good luck

Luke MacDonald · 09-12-2013, 02:30 PM

Thanks a lot for the reply and info. I appreciate it.

One thing I'm wondering though is that I have never had this interference sound issue when recording vocals, despite using the same chain as recording instruments (mic to DMP3 to gearbox to laptop). Can you or anyone infer anything from that which would help in figuring out the cause of the interference?

Thanks!

RunBeerRun · 09-12-2013, 02:36 PM

I've had ground loop issues, but only AFTER the daw, hooking up speakers to a computer will do that.

I don't know, my cables are so old that volume cuts out and stuff, but I normally use MIDI.

Luke MacDonald · 10-03-2013, 11:31 PM

Just wanted to update that it seems to have been a lamp plugged into the wall that was causing it, which I completely overlooked when trying to figure this out. Thanks for the input everyone.