6DB Attenuator on input side of amplifier or at POE before MOCA filter?

The lines coming in from the street are hot @+13dbmv and i need to attenuate the signal for all devices hooked up to the 9 port commscope amplifier. I will be activating 6 total devices on the amplifier 5 boxes and 1 modem on the VOIP port. All unused ports will be terminated with caps.  Can i use a 6DB forward path attenuator outside at the point of entry before or MOCA filter ? or can i simply place it at the input side of the commscope CSMAPDU9VPI amplifier seeing as this is a 0 gain amplifier