002 rack is gives only feedback loop

[hazelmossobrien]

my 002 rack gives off a horrible violent buzz/hum when i plug into the 1-4 line inputs. it seems like some kind of ground loop or something. i'm coming out of an external pre going into the 002...i tested the pre in other inputs and its fine, as well as testing the cable and patchbay. i narrowed it down to the 002 input, but i dont know where to go from here. help! please!

[hazelmossobrien]

sorry to nag...i need some advice! thanks folks...

[shanabit]

Do you have the switch on the back of the unit set to -10 dBu or +4 ? that switch controls a group of four inputs level whether its Unbalanced or Balance signal coming in the unit.

Also, if you using the 1-4 inputs , check the front of the unit and make sure the button is set to Line/Instrument and not MIC as your coming in from the pre at line level.

I always use inputs 5-8 for my preamps coming in just cause I tend to forget to set the switch on the back and front correctly.

Hook up a stereo out from a keyboard and play it with it set to and the Line/Inst button set in the up position.

[hazelmossobrien]

this is really strange, i built an XLR to 1/4 inch mogami cable to use with my BLUE robbie the preamp, when i run it into my 002 line inuts 1-4 using this cable it gives a ground loop as if the cable was soldered incorrectly. but when i use the same cable in channels 5-8 or test it on my mixing board, its fine. heres the weird part, when i test a store bought cable in line inputs 1-4 it works. huh????

[psycho_monkey]

Originally Posted by hazelmossobrien

this is really strange, i built an XLR to 1/4 inch mogami cable to use with my BLUE robbie the preamp, when i run it into my 002 line inuts 1-4 using this cable it gives a ground loop as if the cable was soldered incorrectly. but when i use the same cable in channels 5-8 or test it on my mixing board, its fine. heres the weird part, when i test a store bought cable in line inputs 1-4 it works. huh????

I'm no expert on these things, but I'd just put it down to the wiring of the preamps in the 002 being wired in such a way as to pseudo balance unbalanced cables (isn't there a DI input as well, that isn't present on 5-8? I'd have to check on the back of my 002, and I'm on the wrong continent at the mo!). Use your design for 5-8, buy some more store-built ones for 1-4, and be happy!

Sometimes it's easier just to get on with things. You can get it to work reliably, and without a PITA workaround, so get on with the music

[hazelmossobrien]

i know, but its so hard to not ask why!! haha, thanx.