VO-BB - 20 YEARS OLD!

Jon Morss · Guest

Moe,

I have the same issue with Mbox 2 mini. It seems to be worse depending on the length and type of USB cable I use. I seem to have pretty good luck, or rather less hum, with the shielded USB cable that came with my Blue Snowball. I did have a gold plated cable that I thought would be better, but it was really bad so I went back to the shielded USB cable.
I really wish they had a power supply option so the Mbox 2 was not powered by the USB.

Good luck.

Moe Egan · Posted: Wed Jan 07, 2009 3:54 pm Post subject:

Hey Guys,

Here's the update. I've played with every plug and chord there is, swapped 'em out and mixed 'em up and still got a buzz. You were right George, it's more of a high pitched buzz than a hum..

Anyway. I never was able to get a new USB hub with its own power, but I DID install ProTools on my MacBook, and guess what...NO HUM or Buzz or anything. So. Plan B goes into affect. Mbox will be used with Macbook.

Next challenge- programming my Zephyr. That's one piece of equipment I don't want to use my normal method of "get a bigger hammer" tech etiquette on!
_________________
Moe Egan
i want to be the voice in your head.
~~~~~

Deirdre · Posted: Wed Jan 07, 2009 4:36 pm Post subject:

I'm using an external monitor with my old Powerbook because my mic was picking up the whir of the HDD.
When the video card is active, Pro Tools' code audio driver causes USB Whine. I've looked all over the net for the cause, and the general consensus seems to liken that whine to a 60-cycle ground hum— like it's the digital equivalent of a ground loop. The damnable thing is that it's "looping" thru the chassis or body of your computer, so there's very little recourse. I've got the best cables money can buy, and I've even put adhesive tape around the video port to keep the metal sleeve of the video cable from touching the aluminum body of the computer.

It's still there. It drives me bonkers. I only hear it on playback, but it pollutes the process.
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IMDB

georgethetech · Posted: Wed Jan 07, 2009 7:32 pm Post subject:

Deirdre:
Consider yourself lucky that it's only in your monitor/playback chain and not in the recording. It is very frustrating indeed. I've seen the problem with Powermac G5, Mac Pro, iMac, and Macbook, and random PC's. It is because the power draw of the Mbox is loading the power supply of your Powerbook too heavily, I surmise. Does it go away or change when you unplug the AC power supply from the Powerbook and run on batteries?
_________________
If it sounds good, it is good.
George Whittam
GeorgeThe.Tech
424-226-8528
VOBS.TV Co-host
TheProAudioSuite.com Co-host
TriBooth.com Co-founder

georgethetech · Posted: Thu Jan 08, 2009 1:15 am Post subject:

You could also try using an external A/D converter, like this one

That's sure to clean up the signal path, basically turning the Mbox into a USB dongle to allow you to use Pro Tools. Then you just run your mic preamp into the A/D, and connect the D/A to your monitors/headphones, and use the SPDIF connections on the Mbox only.
I admit it's a bit extreme, but it will work.
_________________
If it sounds good, it is good.
George Whittam
GeorgeThe.Tech
424-226-8528
VOBS.TV Co-host
TheProAudioSuite.com Co-host
TriBooth.com Co-founder

Edo · Guest

Nice workaround George! Smile

Deirdre · Posted: Sat Jan 10, 2009 1:42 pm Post subject:

I got rid of the squeal by using balanced cables from the outputs in the back of the Mbox to balanced channels of my Mackie. I may not need balanced channels on the Mackie, but the outputs say Line Out TRS.

I've been managing just fine with unbalanced, tip-sleeve guitar cables when I am just using my Laptop, but with the introduction of the extra monitor, the need for balance has become paramount.

I am taking up 2 channels on the Mackie to monitor with I'm using multiple tracks, but it's just all fine. I've not been using the channels with XLR inputs anyway.
_________________
DBCooperVO.com
IMDB

georgethetech · Posted: Sat Jan 10, 2009 3:41 pm Post subject:

Deirdre:
Glad that worked for you, I never thought to ask if you are using balanced cabling. Actually, all of the 1/4" inputs and outputs on the Mackie consoles (except for the inserts) are balanced/unbalanced, depending on which type if cable you use. Make sure you use only TRS ("stereo") 1/4" patch cables. No need to take up two mono inputs with XLR connections. Also, if you are using the XLR inputs your signal is passing through the mic preamps in the Mackie, adding another layer of noise.
_________________
If it sounds good, it is good.
George Whittam
GeorgeThe.Tech
424-226-8528
VOBS.TV Co-host
TheProAudioSuite.com Co-host
TriBooth.com Co-founder

Deirdre · Posted: Sat Jan 10, 2009 4:19 pm Post subject: