[cardani]

Hi, i have aBryston Bp25 and take the  balanced output to vandersteen m5hp high pass filter which cuts at 80 hz an then to a 4bsst2 amp, subsequently from the amp outputs goes to the main speakers and to Vandersteen 2wq subs to each channel and the single ended output of the pre goes to a Dayton 1000 subwoofer amp (for a Swarm 3 sub configuration). yes , a total of five subs.  I,ve noticed that I get a higher noise floor when I turn on the sub amp. I understand my Bryston pre is not true balanced. At another forum i was adviced ¨ if the RCA outputs are in parallel with the balanced outputs on your preamp then what you describe makes sense.¨  I was advised to try the following product for the unbalanced output of the bp25 to the sub amp.  https://www.jensen-transformers.com/product/sub-2rr/  Do you think the Jensen transformer will help in my case?

[Mike Pickett]

If the noise is caused by a ground loop between the sub amp and the main system, the ISO Max device may solve the noise issue.

However, if the noise is originating at the sub amp's inputs, and is feeding back to the BP25 through the RCA outputs, it likely won't help...

Thanks,

Mike

[cardani]

Thank a lot Mike, that makes sense. It is no that I have a ground loop hum; Is just that I get the impression that the mains signal might have a higher noise floor by using the sub amp conected to the bp25 unbalanced output. The sub amp specs are here https://www.daytonaudio.com/product/782/sa1000-subwoofer-amplifier-rack-mountable
Do you think is ok and there is not a possibility of mismatch or to hard to drive situation?  Thanks a lot