Where can find the circuit of this power distributor

So I bought this unit from Madisound but I found the sound is slightly more rounded than I like.  It supposedly filters high frequency RF so it would not get to the component, but it seems like it may have filtered out a little too much.I opened it up but the circuit is well bolted in the internal housing it's a little bit difficult to access.  Just wondering if anyone know what component it might be using.
https://www.madisoundspeakerstore.com/power-cables/supra-mains-power-distribution-block-md06-us/