feedback or really bad metallic sound

[Champloo]

almost gave me a heart attack lol, i dont even know what i did to get that horrible sound, like a really really bad loud metallic sound, and is it because of the way i have my stuff setup?

turntable out --> mpc 1000 input
mpc 1000 output --> sp 303 input
sp 303 output --> mixer channel 1
mixer main outs --> speakers

I record breaks/samples into the mpc 1000 , but in order for me to hear ANYTHING out of the mpc 1000, i have to have the Sp 303's "EXT SOURCE" button lit up. is this what is causing that horrible sound? is this causing a feedback problem?

[Rabot]

Setup sounds fine. Make sure the in/out between 1000/303 are fine.

Also the ext.but is fine.

[Champloo]

i checked all the cables one-by-one, everything seems fine with the connections and cables.

it must've happened when i was in record mode on the mpc and had ext source on the sp 303.

has to be a bad feedback or bad loop somewhere, but im kinda scared to test the theory because i dont think my ears can take it again lol and also i dont want to pop my speakers...

[Champloo]

is there an alternate way to route my stuff so that i can record samples and drum breaks from my turntable into my mpc 1000 to chop them up and still be able to pick up FX from the sp 303?

my mixer only has 1 set of stereo outs and i have my speakers plugged to those..