line 1 & 2

ws up fam well i need some help here well everytime i wanna recording on anyline 1 or 2 i get a hum & feedback sound,but thats only with the instrument not the mic,i have good cables & Im useing a mbox 2......

Can u help me plz? thanks

balanced cables?

im not sure if the outputs on the mpc1000 are balanced or not

alien_brain wrote:im not sure if the outputs on the mpc1000 are balanced or not

They are not. Only the inputs.

I'd reply to the thread starter, but I can't understand what they are talking about.

hes saying he gets a hum when he tries to record to his mbox from the mpc i presume.

yep that right i get a hum & air sound.

Hmm. Well, if that's the case, here's a recent thread from somebody who had the same problem with their mbox setup:

http://www.mpc-forums.com/viewtopic.php ... highlight=


Don't know if they ever got to the bottom of it -- try PMing the guy.

use a gate on the humming track

J WALES wrote:use a gate on the humming track

A gate might not be able to target that low hum, gate's work on volume and threshhold don't they?

Not a specific freq that the hum may be on.

not quite sure either Lamp. it works for me most of the time, quiets it down real nice

A gate will only remove the hum from in between notes (which is when the gate is closed). When a note hits, and the gate opens, the hum will come through too. It would be better to find the source of the hum and solve the problem that way.

Did you try a different cable? Do you have any appliances or florescent lights nearby that could be creating a 60 hz hum? Do you have any audio cables close to electrical wires? If so, move the audio cables away from the power cables, if they have to cross, try to have them cross perpendicular to each other, dont have any parallel runs. Try turning off your computer monitor, if the hum stops, then you know it's your monitor so move your electronics away from it.

... just a few ideas for ya.

It sounds like either defective equipment or a ground loop problem to me.

If it's a ground loop, the first thing to do is try to isolate where the problem is coming from by connecting and disconnecting the devices to see when the problem starts.

Once you narrow it down, the quick/cheap solution is to try lifting the AC plug ground lugs on the offending device with a 3 to 2 AC plug adapter that you can get at any hardware store. This is not the best solution but you can often get away with it in a small setup.

Next "simple" thing you can try is some type of direct box/audio isolation transformer. More money, less possible safety concerns than lifting a ground lug. However, both of the above solutions are not guaranteed to work in every case.

The "real" solution is for an engineer do a complete "star ground" of the whole studio and tie everything to the same ground point to get rid of the imbalances between the different units. You have to know what you are doing to attempt this because not all gear is designed with the same ground schemes and you could end up bringing in more noise or worse -- like getting yourself zapped.

I know an engineer who cleaned up a bunch of lower-end hip hop studios this way when he was starting out. Google "star ground" for more info on what I'm talking about.