Tracing down the hum...

[poolboydave]

I use the Alesis Midiverb II through my Send / Return loop on a Marshall 2203x. When I use a regular guitar cable, things are fine. But when I try to use my wireless, Shure L4, it HUMS! If I remove the Midiverb from the loop and keep the wireless, things are back to fine again.

Can anyone point me in the right direction as to what the hell is causing the 2 to NOT jive with each other? I'm ready to pull out what is left of my hair [img]/images/graemlins/mad.gif[/img] AND THAT AIN'T MUCH.

Thanks, Dave

[poolboydave]

Re: Tracing down the hum...

Can anyone shed some light or have a theory?

[DumpyWumpy]

Re: Tracing down the hum...

Just a THEORY mind you, might be a ground loop? As far as I know the way to eliminate this has something to do with using the right combination of shielded/non-shielded jacks on the end of the cables you are using to connect the amp to the Midiverb...Don't know the exact way you are supposed to do it, but look around online and you'll probably find some info about it...

[Newc]

Re: Tracing down the hum...

Relocate the wireless receiver or get better loop cables that have better shielding. If it was either the wireless or the Alesis, you'd hear it all the time, but since it's only with both the wireless and the Alesis, it's gotta be the cables you're running the Alesis with.

Or you could open the Alesis' case and coat the top panel with some shielding spray or tape.

[metallicarocks]

Re: Tracing down the hum...

Could you try moving the two units away from eachother? Just a theory, but I'll bet somehow the midiverb is sending something into your wireless unit. If that doesn't work, could you switch channels or something?

Kind of a stab in the dark, but who knows?

[Newc]

Re: Tracing down the hum...

Moving one away from the other would be the same as relocating the wireless [img]/images/graemlins/poke.gif[/img]

[poolboydave]

Re: Tracing down the hum...

i've tried just about everything. i'm using george l cables for all connections.

[roodyrocker]

Re: Tracing down the hum...

I recently saw something called a Hum X for about $60 that you plug the power cord into and it supposedly safely takes care of ground lift/hum if due to that. Maybe try that???
I have no experience with it myself, simply saw it at www.musictoyz.com. I have no affiliation with that site nor have I dealt with them before, just simply noticed this product there. Hope it helps.

Rudy

[Ace]

Re: Tracing down the hum...

Are you on the same ground when you plug both in, or do you have to plug in one of the units to other power sources? Have you tried plugging in in different buildings?

[Newc]

Re: Tracing down the hum...

Another idea: have you got the wireless' power cable crossing a signal cable? Even if it's laying on it, it can cause some degree of problem, even with shielded cables (went through that recently at a recording gig where the power supply cable for my Alesis SR16 was crossing a signal cable and I was getting lots of hum/hiss).

[poolboydave]

Re: Tracing down the hum...

[ QUOTE ]
Another idea: have you got the wireless' power cable crossing a signal cable? Even if it's laying on it, it can cause some degree of problem, even with shielded cables (went through that recently at a recording gig where the power supply cable for my Alesis SR16 was crossing a signal cable and I was getting lots of hum/hiss).

[/ QUOTE ]

Really? I do bundle all of my power supply cables for the wireless and Alesis together and stuff it in the back of my rack. So the power supply is touching the Alesis unit itself and will rest on the signal cable. I'll give it a try. Thanks!