There are many ways to connect the Behringer X2222USB to The Power Dynamics PDM-805A.
You can use a pair of RCA to 1/4" TS adapters plug into the X2222USB rear panel L and R "MAIN OUTPUTS" and connect it to PDM-805A rear panel "TAPE IN" via RCA cable.
OR
Connect the RCA cable to the PDM-805A front panel "CHANNEL 8" line inputs so you can utilize its control for level, tone and effects.