KAB RF-1 subsonic filter

Thanks guys. Hooked it up between pre and power amp and it is working. No more woofer pumping.

 I would have thought these very simple instructions would have come with the RF-1 from KAB.

They do. 

I thought KAB recommend install the RF-1 between the phono stage and preamp, so the RF-1 will be out of the chain when playback other sources.

https://www.kabusa.com/frameset.htm?/rf1.htm

The KAB RF-1 is easy to install. Place it in between the phono preamp and control amp or in a process loop.

Thank you for doing the necessary research, imhififan. I don’t doubt that you’re correct. What you write makes perfect sense in the case where one owns a separate phono and linestage, especially since it comes from KAB. I hope the OP reads your comment.

Yes, exactly. If you have a separate phono stage put it between the phono stage and preamp. The KAB then will have a consistent input and it will be less likely to be overdriven into distortion. You could also place it in a tape loop if you have one.