Noisy Hum - Please help! USB, Keyboard, Computer

[Kevin16]

Quick gear outline...
Mackie 32 x 8
Motu 828
Mac G5
Digital Performer
Yamaha Keboard Motif ES8

Noise problem...

No noise issues at all aside from keyboard...

Just got the keyboard...everything works great, no noise for keyboard to mixer, but as soon as I plug USB that is attached to the computer, lots of buzzy noise...tried to ground lift at every point, no luck...

Keyboard needs to be plug into computer in order for MIDI setup to work...

There is no noise when I unplug the USB cable...keyboard sounds great...

I'm assuming this is a loop, but not a tech guy so not sure the issue...

Thanks a ton for help!

Kevin

[chadd]

Do you have any other USB devices connected to the Mac?
I had the same problem when connecting my Yamaha S-90 via USB.
Unplugging my Epson inkjet printer solved it.

[Kevin16]

Thanks for the quick reply...yeah, I tried that. too...still getting that hum

[chadd]

I remember reading about someone solving this problem by lifting the ground at one end of the USB cable,
but I can't remember which forum it was. It might be worth researching.

[HCMarkus]

http://www.unicornation.com/phpBB2/view ... ht=usb+hum

[Kevin16]

OK, there is another hum problem I have encountered...

This is seperate from the USB problem....


This might shed light on it though...

This is strange, but computer off - when I plug the Motif output Right into mixer...NO HUM...plug left(mono) into, lots of hum, un plug the Right out put still hums but not as much...I could just plug in the keyboard with the right only and be fine, problem is - no stereo piano or other sounds...

Thanks for the replies, I appreciate it very much...I will also try the USB thing, too...

Thanks!

[Kevin16]

Wow, I am blown away...

After unplugging and plugging different cables and the like for HOURS, I finally came across the answer!

Wirlwind IMP2 Direct Box - $39.99 a piece!

I have 2 for instruments...

I plugged in the keyboard 1/4 inch into Wirlwind and then into the mixer xrl and flipped the ground switch and hey its gone! Holy crap!

ALSO! It took care of the hum from the computer!!!! Because I also used it on the 1/8 out plug I use for reference, Imovie etc...that was noisy as hell too and just lived with it, now that HUM IS GONE TOO!

It seems to have taken care of the hum with USB cable as well! Holy crap!

I am one hum-free happy camper at this point...

Thanks CHAD & HCMARKUS!

[jon]

Sometimes a dimmer switch in the room or a little space heater in the house can cause the buzz. I plug my mac G5 into an Ebtech Hum X Voltage Hum Filterl. Also switching off the nap function to quiet down the PowerPC 970 v2.2 works well too.