USB Isolator to help remove computer noise.

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E

Ed Witles

Active DJ
Nov 6, 2008
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For those folk using USB audio devices - including the beloved Berry :), you might want one of these. Reason? I ditched the Gigaport b/c it was too harsh and over time, started to act distorted. But still used the mainboard's IN/OUT for real time recording and playback from utoob and etc. So, I activated the HD multichannel for Virtual and used the Creative MP3+ USB for the above IO. But would still get a 'whiny buzz'. Now that I have off time, I disconnected the 3.5mm from the mainbaord and left the USB in. Still had that noise. So, I attached the isolator and the buzz went away - yet audio was perfect. But not going back to the Gigaport. So, I am going to pick up a simple consumer 7.1 device and use that. It is the same one in my laptop rig and sounds great. No noise of any kind. http://electronicsshop.dk/?id=1038 is the item.
 
I have a Presonus Audiobox USB audio device .. never heard a lick of noise. The signal is digital, so any noise would be introduced in the analog parts. Don't try to use bus powered devices, that may be the problem. Laptops and desktops have plenty of noise inducing things (fans, hard-drives, network ports). One reason to stay clear of the headphone jacks as audio outs.
 
Ed, you've been having problems like this for a while now.

Still sounds like a ground loop to me, or just a faulty computer. I get no noise on any of mine (all grounds are lifted on the computers), no matter what card(s) I have plugged in.

I do agree that the Giga is far too harsh sounding though.
 
Well, it probably don't help I am using a American Audio mixer... But to date cannot find one w/ same features I enjoy using. One day might end up w/ a MC6000 or something like it. I had one of those fancy Numarks (PPD5000 I think). Was major whisper quiet but had a bad channel and the built in EQ just never sounded right.
 
Ed,
I'm with Rick on this. The only noise problem I hap was with a HP laptop that had the 3 prong AC Connector. Every time it was plugged in I would get this ridiculous scratching noise on the background. Got a $0.99 ground lift plug and no more problems (Using M-Audio Fast Track PRO and then the Denon HC4500.
 
Not using laptop - but rackmount.
 
Ummm - does that not create a potential shock hazard - esp if outdoors? No thanks....

Noise is like pain. You can try and ease the symptoms w/ meds or just try and cure the root problem.
 
Ok, got the sound device and started connecting. Used the above referenced USB isolator. Since VDJ does not 'see' more than 5.1 in WDM mode - even the giga suffers w/ this, the setup is as follows. See picture below: View attachment 25950 Line in captures the tape out audio for real time live recording. There is one more output I need to setup. The on board line out for utoob and media player. Not a deal breaker, but enjoy it. That was sent through an RCA ground loop isolator. Again, no noise at all. So far, using the generic Windows driver, the fidelity is quite decent based on the resulting recorded file. But plan to install the OEM driver and should notice an improvement in fidelity. That is the same setup my lappy has.
 

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Ed Witles said:
Ummm - does that not create a potential shock hazard - esp if outdoors? No thanks....
Click to expand...

Statistically speaking, you have a much higher chance of getting toasted on a golf course by lightning, than lifting a ground on one item in the chain.

Do you actually put your hands on said computer during a gig, or do you use a mouse or controller which is grounded...?

The big problem with ground loops, is that your equipment is not connected properly -- like you said, just give it a med (isolator), instead of fixing the actual problem... ;)


Just saying, y'know...
 
At least the isolator is being used for it's intended purpose - not to defeat. The issue is the mixer design, I think. Did not have this w/ a fancy Numark. Any exposed metal can be at risk. But in an ideal world (and several hundred lighter), noise would not be an issue.
 
Ed,
My RANE MP44 and A&H S2R will show the damn ground noise with the HP. The computer is the culprit as there is no noise if I use the CD player (Denon DND4500) or other sources. Connect the laptop plug without the lift and the noise is there I even tried the famous Hum X and no dice there was still noise in the background (Less but still audible). Use $0.99 lift and noise is completely gone. Fortunately my new Dells work without a problem but the HP is still backup-
 
Ok, lift ground on PC vs entire rig. Gotcha. I used to remove that third leg on the laptop power supply and since some desktops are not always grounded, I can certainly make a special power cable w/ lift built in. Will need to try that tonite. Just have to make sure there is no bleeder current. Mixer has no grounded AC cord. Only PC and monitor are actually grounded.
 
Ed Witles said:
At least the isolator is being used for it's intended purpose - not to defeat.
Click to expand...


If you have a ground loop, you have multiple grounds. I've read all the stuff on national codes and all, but if you have multiple grounds, you never know where that extra current is going to go -- so yer sorta screwed either way!

13 years on The Farm, and everything in 17 rooms had an adapter on it. Nuker, fridge, you name it.

Funny thing was, the sink got hit a few times by lightning (one of them old steel ones painted white) -- the lightning came right through the back door. We learned to stay out of that room during a storm... ;)


Common sense prevails, and if a storm comes through, get yer hands away from anything metal :)
 
Getting hit with ground differential is usually just a tingle rather than a zap, but you will know it when you get it. For a DJ it's much less of a concern than a guitar player getting a different ground with his hands on the guitar and his lips touching a mic grill. That has always freaked me out and is why I always try to run power from the same source for my mixer and their instrument power and then I will deal with any ground hum from a PA amp being on a different circuit.
 
DJ SVO said:
Ed,
My RANE MP44 and A&H S2R will show the damn ground noise with the HP. The computer is the culprit as there is no noise if I use the CD player (Denon DND4500) or other sources. Connect the laptop plug without the lift and the noise is there I even tried the famous Hum X and no dice there was still noise in the background (Less but still audible). Use $0.99 lift and noise is completely gone. Fortunately my new Dells work without a problem but the HP is still backup-
Click to expand...

Now that's odd. My main playout lappy is an HP, and I have both of the mixers you speak of. Never a peep of noise from either. It's as quiet as can be. Go figure!

Best,

Paul
 
Paul,
Both racks are extremely quiet and I like that. It's just the charger for the laptop that has given me headaches. If the laptop is unplugged and running on it's battery alone it's also extremely quiet but plug it in without the lift and there's a scratching noise in the background. My Dells and Vaio's have also been quiet, it's just that one that's the problem.
 
DJ SVO said:
Paul,
Both racks are extremely quiet and I like that. It's just the charger for the laptop that has given me headaches. If the laptop is unplugged and running on it's battery alone it's also extremely quiet but plug it in without the lift and there's a scratching noise in the background. My Dells and Vaio's have also been quiet, it's just that one that's the problem.
Click to expand...

Interesting. I have chargers permanently mounted in 2 racks for HP. No noise. Weird! Have you tried a different charger? There are many of various output wattage that cover the same voltage from HP. If it has the proper end connector, it'll work. If ya want I can give ya the part # of mine.


Best,

Paul
 
DJ SVO said:
Paul,
Both racks are extremely quiet and I like that. It's just the charger for the laptop that has given me headaches. If the laptop is unplugged and running on it's battery alone it's also extremely quiet but plug it in without the lift and there's a scratching noise in the background. My Dells and Vaio's have also been quiet, it's just that one that's the problem.
Click to expand...
Play Ghostbusters and it will go away! :)

 
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