Digital Dirt Sound ONLY When DP is Open

[Aaron Guidry]

Hello,

I've noticed that when DP is open, my synth that I have plugged into my mixer generates a very low static noise. It doesn't sound like a ground loop hum...more just like a fuzzy/dirty output.

However, when DP is closed OR when DP does a task that takes a moment (such as saving a large project), the noise disappears. It immediately re-appears when the task is done.

I'm using an UltraLite. The two main outs go into my mixer, as well as Analog 1-2 out. The synth plugs directly into the mixer, bypassing the UltraLite altogether.

I've troubleshot cables, inputs, outputs, Master Volumes, headphone jack, etc. What I've come to is that this sound only shows up when DP is open. Nothing even has to be record-enabled; it's just there. When DP is booting up, I can hear it start to make noises as plug-ins, etc. are loaded.

What about opening DP could be causing this?

Thanks!

Aaron

[Michael Canavan]

There are no cables running inputs into the Ultralite?

Dumb question, but the main outputs and the 1-2 outs are running different tracks right?

If nothing is going from your mixer back to the Ultralite, then it's probably your mixer that's at fault here. There's no logical reason I can think of why an audio card plugged into a separate track on a mixer would have any influence on a Synth, unless they're physically touching, then it's a possible grounding issue in the synth mixing with the magnetic field of the UltraLite.

[Aaron Guidry]

I tried a different mixer. The problem was still there.

Then I tried a shorter AC cable for the Triton. The sound lessened, but it's still there. I'm assuming it's electrical, but not sure what else to do about it!

[stephentayler]

What about MIDI connections? I recently had noise appear on outputs of a a Roland Piano I had plugged into the UltraLite, but the noise was only present when I either had a MIDI cable connected to the Ultralite, or a USB cable (from keyboard) connected to my Mac.

I didn't find the solution, as it was not a permanent connection.

SWT

[Aaron Guidry]

That's very interesting, Stephen.

The MIDI cables don't seem to affect this noise I'm getting. The only thing that truly fixes it is unplugging all cables from the UltraLite OR all cables from the mixer except the lines from the Triton. I've even tried going direct from the Triton to the UltraLite...still dirty unless I unplug all other cables. (My cables are all good, btw...pretty sure it's not a cable issue)

The sound is very similar to RF interference. Any thoughts on that??

[MIDI Life Crisis]

Are you using a USB hub? I've had static as you describe from USB problems. Also, check that no wires carrying any electrical signals are anywhere near your speakers or cables carrying audio signals to your speakers as well as crossing power cables to the speakers.

[Aaron Guidry]

I'm not using a USB hub. Other connections: Firewire 400 from the UltraLite the Mac and an external HD connected via Firewire 800 to the Mac, iLock via USB on the Mac, and keyboard via USB on the Mac.

My speaker power cables and XLR cables run parallel to each other down the speaker stand. They are separated by two columns inside the stand. Before I tear my set-up apart, do you think that has something to do with it? If so, why would I only hear the dirt when I plug in the Triton to the mixer? Without the Triton plugged in, things are as clean as a whistle.

Thanks for the help!!

[Aaron Guidry]

UPDATE: I separated ALL electrical cables from audio cables, and the noise is GREATLY reduced, not even there (hope it stays that way!).

Thanks everyone for contributing to solve this puzzle. I appreciate it! MOTUNation, once again, saves the day.

[MIDI Life Crisis]

I rest my case. You're most welcome.