studio patchbay issue (signal decrease)

[uglytaco]

Ok guys im stumped on this. If anyone could shed some light or suggestions that would be awesome. The whole balanced and unbalanced thing really does my head in.

So my set up is this

Preamp (unbalanced XLR output) into neutrick patchbay which is halfnormalled into my power amp which goes to my speakers (jbl 4312)

When i patch into the front (i.e take a split from the output of my preamp) the volume i get out of the speakers decreases dramatically like maybe half. I can still hear the signal but it is much lower.

Im using unbalanced patch cables, and the patchbay is balanced.

Can anyone think of something obvious going on here?? Is it even a question of balanced/unbalanced or something else at play.

[dave01.cooper]

Robert - are the patchbays one of these models?

http://www.neutrik.com/en/products/audi ... nys-spp-l1

If so, could be the grounding clip on the jack cards. We use to run those patchbays and was chasing my tail trying to figure out some grounding/audio loops and found out it was those little blasted clips had been seated oddly and was half normalling from top to bottom on one card.

Also - is the input of your power amps balanced or unbalanced?

cheers

[uglytaco]

Hey dave yep thats the one i have.

my power amps inputs are unbalanced as are the outputs from my pre amp.

so you think those grounding clips could be doing something strange to the circut? im not getting any ground loops or anything just a decrease in signal?