The DB9 PhonePatch is a simple device with a standard RJ11 telephone input jack and an output cable terminating at two RCA plugs. A 600 ohm audio transformer isolates the input from the output reducing the possibility of hum and noise, and will not keep the telephone line open.

Applications for the DB9 include broadcast, conference rooms, phone training, or wherever a phone conversation needs to be recorded or heard over a PA system.

The DB9 rear plate has two screw holes for convenient mounting.