If you only use a single source i.e. CD player only, put the BAM between the CD player and the pre-amp. Output from your CD player to the input of the BAM, output from the BAM to the input of your pre-amp. You will need one extra pair of interconnects.
If you use multiple sources and your pre has tape in and tape out rca's on the back. Using two pairs of interconnects, take the pre's tape out put into the BAM's input, take the BAM's output and connect it to the pre's tape input.
If you use multiple sources and your pre does not have tape in and tape out rca connections, connect the pre-amps output to the BAM's input, connect the BAM's output to the amplifier's rca inputs.