Alternative approaches to electronic music through speculative sound circuits are discussed. These approaches borrow from emerging theories in speculative design and the work of designer/theorist Anthony Dunne. Dunne’s post-optimal technological object is also discussed along with slow tech and the slow movement. George Brecht’s Water Yam and the absurdist creative strategies of the Fluxus movement are seen as prototypes for speculative design. With particular reference to electronic music and speculative sound circuits, the instruments of Percy Grainger and Gijs Gieskes are considered. Speculative sound circuits are viewed as part of a broader theoretical framework in relation to critical making, as referred to by Garnet Hertz, John Cage’s ‘music of objects’ and David Tudor’s ‘composing inside electronics’. Finally, a specific example of the author’s work as Dirty Electronics, Making for Radio and Speculative Circuit, are offered up to illustrate speculative sound circuits along with spontaneous and intuitive approaches to circuit building, rapid prototyping strategies, and making as a processual part of performance. Indeterminate and chance-based music, models for extended instrumental techniques, and questions arising concerning physiologies in performance and human-machine interaction are also reflected upon.