PPC-9M-UU

Hello - I have a quick question - I use to have 4 set top boxes with a cable modem for my internet thru the PCC-9M-UU amplifier and now I no longer have any of the TV set top boxes.  If I only have the cable modem now, can I just remove the PCC-9M-UU amplifier and run the comcast cable straight to the cable modem?  Thanks, Paul