AJH Synth-Ring SM (Black)

Discrete transistor ring modulator with dual sub bass generators and a CP3 style mixer in one focused utility module.

Ring SM centers around a discrete transistor Gilbert Cell ring modulator, AC coupled and voiced for the character of early 1960s designs. It behaves differently from modern IC based ring mods. The overload response feels organic and the distortion has weight rather than fizz.

The core offers three inputs. X acts as the carrier, Y as the main modulator, and Z as an additional modulator with a different phase relationship to the core. Using Y and Z together creates more complex and sometimes more resonant spectra. You can drive all three at once, which turns simple oscillator pairings into dense, shifting sidebands.

The Double switch adds a practical twist. It internally routes the X input to Y, so a sine or triangle at X produces an output one octave above without patching a second source. It is a straightforward way to extract harmonic content or create octave lifted tones from a single oscillator.

Two independent sub bass generators expand the module beyond ring modulation. Sub Bass -1 outputs a shaped sine one octave below X. Sub Bass -2 goes two octaves down. These are not square wave dividers. The waveforms shift from rounded trapezoids at low frequencies to more sine like shapes higher up, keeping harmonic content controlled. They sit firmly in a mix and add weight without turning muddy. They track reliably up to around 1 kHz at the input.

The built in five channel mixer follows the discrete transistor CP3 topology from early 1970s modular systems. It runs DC coupled, so you can mix audio, control voltages, or both. With nothing patched, the ring mod and sub bass outputs normal through the mixer internally. Insert a cable and that channel becomes a standard mixer input. Driven hard, it adds classic transistor saturation. Kept moderate, it stays clean and stable with minimal interaction between channels.

Ring SM works as a tone shaper, a sub generator, a CV utility, or the center of a complex modulation patch. In a compact system, it replaces several modules while adding a distinct transistor character.