All sorted!

[StevieD_FenderP2009]

Hey guys

I've recently bought myself a Yamaha SPX 90 MK2 effects unit for getting a nice Chorus, Flanger and Phaser effect from but whenever it's plugged in to the effects loop of my Trace Elliot AH250 SMX pre amp, there's a really loud hissing noise even when the effects loop dial on the pre amp is turned off and when the output from the amp is turned off. As soon as you take the cables out of the Yamaha that go out to it from the Trace, the hissing stops.

Is this a grounding issue? If so, how do I stop it as there's no ground lift switch on the Yamaha and the ground lift switch on my Trace does nothing.

I really don't know what to do. I should note, everything is in a 20u rack mount set up with plastic gromits on the bolts and all is being powered by a Samson PB10 Pro power conditioner.

Cheers
Stevie

Edited April 18, 2012 by StevieD_FenderP2009

[rmorris]

Sounds puzzling. But can you test the SPX90 with another amp with an fx loop ? Is it okay if you plug into the SPX 90 direct from bass (or via pedal / buffer etc ) then into the input ( not fx return ) of the Trace AH250 ? etc...

[StevieD_FenderP2009]

Thanks for the advise dude. I found out it's my cable. It had a split in it causing it to hiss. I tried 3 other cables and there was no hiss.

[rmorris]

Right. Which cable was it ? Split in the screen or signal or both ?
Congrats on sorting it.

[StevieD_FenderP2009]

Split the whole way through haha. There was literally a 3rd of the cable still connected and I didn't notice it somehow xD