electrical hum

chrisrob101 wrote:
Isn't a ground loop isolator the same thing that's in a DI box or is it something different? Where and how would I place one on the signal chain? It looks like an RCA connection to me.

From what I read is that the DI Box is used for more extreme cases. I had bad hum issue coming out of my monitors and the isolator fixed it for me.
I'm sure you could find ones with jacks instead of RCA.

if you tried the di box, and tried lifting the ground, then its not a ground loop.

Important update: To conclude, it was definitely a ground hum problem. I first tried to get rid of the hum using a Behringer DI100. However, as mentioned it didn't completely work. There must have been a problem with it because I bought a Behringer DI20 instead which is an active 2 channel DI box which is perfect for synths and drum machines and the ground lift works perfectly. I now also use much shorter cables, I went for some patch cables from the MPC to the DI. One more thing, I also cleaned all the jack connections with contact cleaner, just in case.

So, it goes like this. 1) DI box - attenuators down and ground lift up. 2) Shorter cables. 3) Give the jacks a good clean. Job's a good one.

TBH, I would recommend this to anyone. Balancing the signal into the desk seems to have cleared up an issue I had with signal hum (airy hum) coming from the MPC. Also, the DI20 is a great option and is very economical. Thanks you guys for all the help.

so it was a ground loop and the first di just wasn't working properly?

To sum up, yeah.