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SOLVED!!!! Lots of interference/noise in setup...


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Here's my setup - it's very simple. Win10 laptop connects to Roland Quad-Capture via USB. Quad-capture has 1L and 1R balanced outs in the back. I run TRS balanced cables from those outs to my Mackie HR824 monitors. The Mackie has only balanced inputs.

 

This scenario works fine - if that's all that is going on. No hum, no interference through the monitors.

 

However, if I plug in the power to the laptop to run off that instead of the battery, a bunch of heavy static and interference kicks in.

So I'm running off the battery for the time being when using the monitors - but I'd like to fix this and not have to stop using the setup when the battery needs charging.

 

Similar issue with the big wall-mounted video monitor that I love to use for mixing and working in the DAW. The laptop has a video out on the back, but when I plug in the monitor to the laptop, another big bunch of noise and static kicks in. Sigh....

 

Here's the odd thing that applies to both cases above - the headphone outs on the Roland do NOT carry any of this static and noise. The racket only comes through the Mackie monitors. In case you missed it, I'll repeat that everything here is balanced - the outs, the ins, and the audio cables.

 

All the audio gear is plugged into the same power strip. It doesn't matter where I plug in the power for the wall-mounted big monitor - always the noise kicks in.

 

I've flipped the ground lift on the Quad-capture this way and that way - I've relocated the Quad-Capture across the room from the wall video monitor and the Mackie audio monitors.

 

It's hard to figure out exactly where the noise and interference is entering the chain. The laptop power cord of course must be a source - however, why is the noise not coming through the headphone outs? The wall-mounted monitor could be generating a field of interference, but how is it getting into the balanced cables? And again, why does that interference only appear in the Mackies and not in the headphones?

 

I'm confused.....any help appreciated.

 

Oh, yes - one other odd thing. The Roland manual for the Quad-capture says to use only the USB cable that came with the unit. And if that gets lost, buy the replacement from them. I'm thinking this is just to keep Roland from getting blamed for user problems that are traceable to a crappy cheap USB cable. But is it possible their USB cable is actually different and somehow prevents this kind of issue?? (I have a hundred USB cables all tossed into a drawer - I have no idea which one is the original Roland cable or if I even still have the original.)

 

 

nat

 

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Here's my setup - it's very simple. Win10 laptop connects to Roland Quad-Capture via USB. Quad-capture has 1L and 1R balanced outs in the back. I run TRS balanced cables from those outs to my Mackie HR824 monitors. The Mackie has only balanced inputs.

 

This scenario works fine - if that's all that is going on. No hum, no interference through the monitors.

 

However, if I plug in the power to the laptop to run off that instead of the battery, a bunch of heavy static and interference kicks in.

So I'm running off the battery for the time being when using the monitors - but I'd like to fix this and not have to stop using the setup when the battery needs charging.

 

Similar issue with the big wall-mounted video monitor that I love to use for mixing and working in the DAW. The laptop has a video out on the back, but when I plug in the monitor to the laptop, another big bunch of noise and static kicks in. Sigh....

 

Here's the odd thing that applies to both cases above - the headphone outs on the Roland do NOT carry any of this static and noise. The racket only comes through the Mackie monitors. In case you missed it, I'll repeat that everything here is balanced - the outs, the ins, and the audio cables.

 

All the audio gear is plugged into the same power strip. It doesn't matter where I plug in the power for the wall-mounted big monitor - always the noise kicks in.

 

I've flipped the ground lift on the Quad-capture this way and that way - I've relocated the Quad-Capture across the room from the wall video monitor and the Mackie audio monitors.

 

It's hard to figure out exactly where the noise and interference is entering the chain. The laptop power cord of course must be a source - however, why is the noise not coming through the headphone outs? The wall-mounted monitor could be generating a field of interference, but how is it getting into the balanced cables? And again, why does that interference only appear in the Mackies and not in the headphones?

 

I'm confused.....any help appreciated.

 

Oh, yes - one other odd thing. The Roland manual for the Quad-capture says to use only the USB cable that came with the unit. And if that gets lost, buy the replacement from them. I'm thinking this is just to keep Roland from getting blamed for user problems that are traceable to a crappy cheap USB cable. But is it possible their USB cable is actually different and somehow prevents this kind of issue?? (I have a hundred USB cables all tossed into a drawer - I have no idea which one is the original Roland cable or if I even still have the original.)

 

 

nat

 

 

Well, I'm just still up and about and reading. You will doubtless get an answer from someone more knowledgeable about this than me. I'll just guess/offer - maybe there is something in that headphone out that defeats/shunts the noise. And balanced or not beware of compact fluorescents, and space heaters, chandeliers with dimmer switches, toasters, and anything else that generates some serious RF. There may be something about the gear itself rather than the cables. Just another guess.

 

I've had my own issues with my system in the past. Everything here is plugged into good quality strips that are plugged into a Furman 1215 power conditioner now. I also have an Ebtech Hum Elimintator that goes on the AC plug, but it didn't help when confronted with the things I've mentioned, and since I've sussed it out it some regarding said culprits, it doesn't seem to do anything to further reduce the system noise I still I seem to have either, which is somewhere under -66 db currently. What little noise there is I press out of the way with downward expander on my Finalyzer Plus if I feel it's necessary. No issues at all going balanced from my Finalyzer to the Tascam VL X5's fwiw. Good luck, and g'nite.

 

:wave:

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My memory of what it used to be, so I don't recall just how the discussion went, but I do recall something about a noise problem with the Mackie HR824 monitors that had to do with the cables used to connect them. Maybe it's worth playing with Google or another search engine and see if you can find a related discussion on line.

 

Have you tried the same setup with a different computer? This is relatively old (in technology years) stuff so you probably had it all working on another computer. Also, if you have the computer's Ethernet port connected to anything, try disconnecting it.

 

I doubt that the trouble is from noise getting in through a signal cable, I think it's because of noise getting in through the ground connection. You could try doing some surgery on the cables connecting the speakers to the interface by disconnecting the shield from Pin 1 (or TRS sleeve) on the interface end. It's possible that the magic Roland USB cable doesn't have the connector shell connected end to end.

 

 

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Thanks for the ideas - RV: right about all the possible sources of RF. That's an old problem I solved some time back. Oddly, one of the biggest culprits is my laser printer - it puts out a dot-dash series of beeps that gets into the audio via guitar pickups or monitor cables. I think I have those issues sussed out.

 

MR: what's new here is my use of a laptop and the new big wall-mounted monitor. I did have my studio in a different room with a different (desktop) computer and I was able to liquidate the noise gremlins in that setup. No ethernet cable - all wireless using an onboard transmitter. I'll try disabling the wireless adapter, see if that does anything.

 

Here's the idea this morning's coffee brought to me - the USB has to be somehow "leaking" the noisy signal into the monitor outs, which are physically located close together on the Quad-Capture. Through the Quad-Capture case maybe? Or just inside the case. At any rate, the noise jumps from the USB to the monitor outs, but doesn't jump into the headphone out signal path - the headphone out is on the front of the Quad-Capture while the USB and monitor outs are close together on the back.

 

I'm going to experiment with my stash of USB cables - if there's any difference in noise transmission between any of them, that will be an important clue.

 

nat

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Hey Nat

 

I currently use a Roland interface (UA-101) myself and also other Roland interfaces in the past. I was going to suggest the ground lift switch, but I guess it didn't help you at all. I think your noise issue could be due to a one or two reasons.

 

It might simply be the electrical layout of your laptop that's creating noise. I had a Toshiba laptop in the past that had its AC jack right beside the external monitor jack, whenever an external monitor screen was plugged in at the same time as the AC adapter, I would get weird screen interference.

 

Another thing I'm suspecting your issue might be due to a ground loop. You mentioned that you have all your devices plugged into one power strip. Try moving your studio monitors power plug to another wall outlet on its own. I've experienced a similar noise issue with a PA speaker, once I re-plugged the speaker to another wall outlet the noise was eliminated.

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Yeewhowahahaha! I delved into my snake pit of extra USB cables and the second to the last one in the whole pile totally removes all the noise and interference coming through the Mackie monitors! Not any of the ones labeled "shielded", not any of the expensive ones with the gold connectors, just this one working cable that must be the original Roland USB jobbie.

 

It's purplish-blue in color (is that a Roland color?) - has no markings - is discouragingly rather thin and bendy, not as long as I'd prefer, but now I'd worship at its feet except that it has no feet.

 

Trials and errors...the path to an occasional success!!

 

Thanks for the ideas and commiserations....

 

nat

 

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I use USB cables other than the supplied Roland cable with no problems all the time. I believe that Roland just wanted to make certain you were using a USB2 cable (as opposed to a slower USB1 cable) with their unit as they weren’t as common in the days when it was first released.

 

As far as hum and noise ... I think if you trace it all out you’ll find the problem is centered by the fact that SMPS wall wart supplies do not have a ground reference so whatever they power also doesnt have a ground reference. So in order to get grounded that unit has to find ground from other gear hooked up to it. That’s where your problem lies.

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Yeewhowahahaha! I delved into my snake pit of extra USB cables and the second to the last one in the whole pile totally removes all the noise and interference coming through the Mackie monitors! Not any of the ones labeled "shielded", not any of the expensive ones with the gold connectors, just this one working cable that must be the original Roland USB jobbie.

 

It's purplish-blue in color (is that a Roland color?)

 

Yes, I believe that Roland does paint some things purple. If you have an ohm meter or even a bulb-and-battery continuity tester, check the continuity between the shell (the metal outside) ends and see if they aren't connected on the purple cable and they are on the other cables.

 

 

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Thx Don for the input - I also used USB cables other than the Roland cable for years with no problems. It was only when I changed the studio computer from an older desktop to a new laptop that the noise problems started. Interesting that some computers have problems, some don't - electrical gremlins are tricky little things....

nat

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I've thought about buying a decent electrical multi-tester for a couple of years, but I get overwhelmed looking at all the varieties and price levels and never actually pull the trigger. Got any suggestions for a model good enough for studio electronics/car/house/appliance general duty?

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