Wow! Large amounts of hiss from BB outs?

I have been setting up the BB to start using live and just using cans. However today I plugged it into the PA for the first time and the background level of hiss is not really acceptable.

Volume control on the BB makes no difference…gain on the channel is at unity but the noise is not really what I would expect in this day and age!

Is this a know issue with the audio side of the BB?

Thanks

I just tried this with the PA speaker I use (Alto Trouper). With the BB set at 100 (normally it’s around 40-45) and not running, the only time I got hiss is with the PA gain up to about max gain (it normally is set at about 50% for the BB). Pretty quiet in normal operation.
If you set the BB volume up towards 80-90 and set the PA gain down to compensate for the larger signal, does that reduce the hiss relative to the drum audio? Is the BB near any other gear that has a feed to the PA?

Thanks Mark…I can report that the crisis is over haha! Seemed it was a dodgy RCA cable being used in the BB input jacks. The noise-floor is now back to an acceptable level!