A pair of MSB Technology Subwoofer Isolators with XLR connectors is for sale. MSB Sub Isolators are made for any
DAC or Preamp with only a single pair
of balanced amplifier outputs. How, then,
to provide a musical signal to powered sub(s)? The usual work-around is a Y-cable. Unfortunately, noise created by the powered
sub will leak back to your amp(s) through the Y-cable, thereby corrupting its
The Sub Isolators provide a perfect pass-through to the amp(s), and a fully
isolated balanced output for the sub.
The following can be found at MSB
Technology's website: "Sub-woofers
need a lot of power and they are not too sensitive to high-frequency noise.
Speaker manufacturers like to match their subwoofers up with some pretty low
quality amplifiers, with switching power supplies and not much filtering.
The sub-woofers sound good, but the problem we found is that this noisy
subwoofer is connected to your ultra clean, ultra precision analog output. This
creates obvious noise and distortion on your main amplifier and speakers. It's like serving fine wine in dirty glasses.
"It all started when we had a
customer who preferred their preamp. In our experience, there is no
preamp that sounds better than having no preamp.
Noticing a powered subwoofer, we turned off the subwoofers and the sound
came alive. Turned them on but disconnected the input. Still sounded great.
It was not the sound of the sub that was the problem, it was the
pollution caused by it.
The solution was an isolation module that provides a subwoofer output that is
completely ground isolated from the source and blocks noise and feedback.
One of the roles of a preamp is to provide dual isolated outputs, but as
an all purpose tool, it filters and isolates all the outputs. It blocks much of
this sub feedback, but at the expense of the quality of the mains. This
isolator allows a minimalistic signal path. This gives your primary amplifier a
perfect signal and your subwoofer an isolated input."
Purchased new from MSB in 2017. Selling only as a
pair for asking price. Check my feedback
and buy with confidence.