Running effects on live vocals with bass rig

I'm recording my vocals right now with an M13 and not getting any significant noise.

I am using a Digitech Vocal 300 as a buffer since it has a 1/4 inch out. You may need some sort of balanced to unbalanced conversion straight into the effects before it gets to the mixer.

Edit::: I may have this confused a little, are you running the bass and vocals into your main mixer, then an insert out to a bass amp?

 

Maybe. If it doesn't get it done, MF has a decent return policy.

I know that in the past when I tried to run from a mixer direct to an instrument amp as a personal monitor, it was really crappy sounding with lots of noise. I think it was a combination of impedance problems and ground loops, but I am not certain. If that Nady does as it says, it should help both situations.

I'm still a little uncertain of your signal chain, but there are a handful of places where the Nady could slide in regardless of your routing to improve you're results.

 

Your "bro" should get himself a small PA. Putting vocals into an instrument amp is a junior high school, 1st band situation. (We've almost all been there briefly)
Unless it's a Great mixer, studio quality, chances are the preamps and impedence transformers are cheap and it's line level too low.
"Bro" needs to get, at least, a mic preamp (like ART for $60 or less) 1/4" out into effects (Which ones by the way?) into one amp input, you in the other (with other effects if you want). If you want to both use the same effects, esp if overdrive is involved, that's crazy. Unless you are so avant guard & abstract that noise is what you want.

 

Now that I fully understand your situation, I'm with Bassbrass. The vocals need their own signal chain all the way to the powered speaker or pa, unless the point of the vocals is something way out of the norm.