G2 engine has a high pitched HUM when connected via USB

jellytots · Joined: Nov 20, 2006 Posts: 12 Location: eire

Hi guys,

Heres the setup:

iMac with a buspowered (I also tried powering it seperately) firewire soundcard, g2 engine with outputs 1&2 connected to the soundcard, the usb connected to the iMac

the result is a high pitched hum added , mostly to the left signal, and its quite loud. it totally disappears when I disconnect the usb tho.

now check this, when I connect the usb through a hub, the hum loses a bit of volume....but its still there, again - it totally disappears when I disconnect the usb.

this kills the groove, having to shutdown the editor/disconnect usb to record, as I like to record on the fly as I experiment with patches...

anyone experienced this before?

mosc · Posted: Mon Feb 05, 2007 5:00 pm Post subject:

Try searching on usb and noise on the Clavia Forums and you'll find a lot of discussion on this topic.

jellytots · Joined: Nov 20, 2006 Posts: 12 Location: eire

jellytots · Joined: Nov 20, 2006 Posts: 12 Location: eire

well, after checking a few of those threads...it seems the solution is in ground-lifting the computer, and perhaps using a quality usb cable...

someone mentioned using a threeprong-to-twoprong adapter, as a 'non-destructive' way of removing the ground.
anyways, i just used a twopronged cable I had lying around for the g2engine, and its improved considerably.....certainly recordable now for 95% of stuff, when you really crank the gain you can notice a big difference between usb-plugged-in and usb-unplugged

Just gonna ground-lift as much stuff as possible...

anyone know if its a bad idea to ground lift my iMac ?

Keysandslots · Posted: Tue Feb 06, 2007 7:10 am Post subject:

I noticed this same thing when I used a USB extender, resulted in a very loud hum. Fortunately (sort of), I had a flood in my office, ended up having to move everything around, and eventually moved the keyboards closer to the computer so I could use a USB cable that was within the 16' spec. I'm on a PC by the way.

Might be the cable, but since this seems to be a common problem, I'm starting to think it has something to do with the instrument as well.

Randy

mosc · Posted: Tue Feb 06, 2007 11:28 am Post subject:

I remove the grounds on all of my audio equipment. I permanently remove them, but ground lifters are OK if you don't want to deface the cords. I even removed the grounds on the power plugs in the walls in my studio.

Removing the ground on your Mac will not harm it at all. Computers are the worst offenders. The fact that you have a high pitch noise points directly to a computer.

I have a friend that thinks I'm crazy because grounds are a safety device. He is not an electrical engineer. I hate to play in his studio because there is a lot of noise and hum. My studio is very quiet.

mosc · Posted: Tue Feb 06, 2007 12:40 pm Post subject:

I just posted some more information that might be helpful...

http://electro-music.com/forum/topic-16104.html