The majority of musical robotics performances, projects and installations utilise microcontroller hardware to digitally interface the robotic instruments with sequencer software and other musical controllers, often via a personal computer. While in many ways digital interfacing offers considerable power and flexibility, digital protocols, equipment and audio workstations often tend to suggest particular music-making work-flows and have resolution and timing limitations. This paper describes the creation of a hardware interface that allows direct communication between analogue synthesizer equipment and simple robotic musical instruments entirely in the analogue domain without the use of computers, microcontrollers or software of any kind. Several newly created musical robots of various designs are presented, together with a custom built hardware interface with circuitry that enables analogue synthesizers to interface with the robots without any digital intermediary. This enables novel methods of musical expression, creates new music-making work-flows for composing and improvising with musical robots and takes advantage of the low latency and infinite resolution of analogue circuits.