Ampeg 200t DI box buzz?

[capncal]

So i've been experimenting lately on my rig. i like the idea of going DI as well as miking my cab.

What i have discovered is my ampeg 200t buzzes when i try to run a DI box parallel to the board.

meaning, when i use my sansamp bbdi straight to the board, it sounds great. when i run the bbdi into the amp, it sounds great. but when i try to run the xlr into the board at the same time as going parallel into the amp, it buzzes.

i tried a cheapy standard DI box, does the same thing.

got an ART tube pre-amp, same thing. although this thing buzzes really bad. not thinking it's designed for that specific application.

just wondering if there's an electrical issue with my head or if i'm just doing it all wrong.

i've got a small combo amp i'm going to play with this week to see if i get the same results. just wondering if anyone has experienced this issue with this head or any other for that matter.

 

[tbirdsp]

You are getting a ground loop hum. If none of the DI's have a ground lift switch, try a ground lift XLR adapter.
http://www.sweetwater.com/store/det...g&matchtype=&gclid=CNDOl5eLjbkCFXBo7AodGEwAeQ

I've got a RBI preamp and had a ground loop hum last time I used it at a gig. I don't know why Tech 21 doesn't put a ground lift switch on their units. I had to just use a regular DI box which had a ground lift - which means I wasn't getting any of the RBI tone to the FOH PA
I have since purchased some of the adapters I linked above.

 

[JimmyM]

+1. I have one of those adapters and it always fixes the problems I have occasionally with amps that don't play nice with my DI.

 

[capncal]

ground loop hum. indeed. i suppose that should have been the first thing to check. the generic DI box i have that works best has a ground switch. but it still causes a bit of noise, but not near what the others do. i'll check out an xlr adapter.

thanks.