The GLX Audio Balsam is an eight-voice hybrid modal synthesizer engineered specifically for gradual harmonic movement, long-form polyphonic portamento, and rich devotional drones. Rejecting the traditional piano-style keyboard interface, it introduces an expressive workspace driven by tactile sliders and specialized pitch-slew mechanics.

The design of the Balsam draws artistic inspiration from two distinct realms: the microtonal, sliding inflections of a pedal steel guitar, and the expansive, multi-second polyphonic portamento profiles characteristic of classic vintage synthesizers like the Oberheim OB-8 and Yamaha CS-80. It presents an interface consisting of eight standalone trigger keys paired with eight independent voice-allocated sliders that function as individual pitch benders. This layout encourages gestural performance techniques—nudging voices out of tune, creating evolving chord clusters, and sustaining rich, ambient soundscapes reminiscent of Indian tanpuras or traditional shruti boxes.

The synthesis core combines high-resolution digital virtual-analog oscillators with purely analogue filtering and amplification. Each of the eight voices hosts two oscillators equipped with independent glide and unique Viscosity controls. Viscosity adds a simulated fluid drag to pitch-bend inputs, causing the oscillators to lag organically behind manual slider movements. Because both oscillators within a single voice can run independent glide and viscosity rates, a single note can easily phase, thicken, and beat against itself. For performance modulation, Balsam includes an internal modulation matrix, a slider-tracked stereo panning system, and an integrated eight-channel polyrhythm sequencer that utilizes the physical sliders to manipulate clock subdivisions on the fly.