Released in 1986, the Yamaha SPX90II built on the proven success of the original SPX90, refining its capabilities while retaining the same celebrated sound character that made its predecessor a studio and live sound legend. Yamaha’s goal with the Yamaha SPX90II was not to reinvent, but to enhance. The result was an upgraded digital multi-effects processor that preserved all 30 of the original’s acclaimed preset programs, expanded their control ranges, and improved their creative scope.
This included extending maximum delay times, doubling sampling time in Freeze mode, and increasing flexibility in modulation-based effects. The Yamaha SPX90II remained fully MIDI compatible, featured comprehensive user memory, and continued Yamaha’s tradition of offering professional effects processing in a compact, affordable, and highly versatile rack-mountable unit.
The Yamaha SPX90II provided a selection of 30 ROM preset effects, each with up to nine editable parameters, alongside 60 RAM locations for storing custom creations. Reverberation programs covered Hall, Room, and Plate types, offering natural, spacious ambience with adjustable decay, pre-delay, high-pass and low-pass filtering, and room size.
Early Reflection algorithms simulated initial sound reflections for tight, realistic ambience in vocal, percussion, and instrument applications. Delay and Echo programs allowed independent left/right timing for stereo width and depth, while modulation effects such as chorus, tremolo, stereo flange, symphonic, and stereo phasing could be adjusted for rate, depth, feedback, and delay time.
Specialist effects further expanded the Yamaha SPX90II’s appeal. Freeze mode offered up to two seconds of audio capture with variable start/end points, pitch shifting, and MIDI triggering, ideal for creative looping and sound design. Pitch Change provided fine adjustment in one-cent increments, up to a ± two-octave range, with feedback control for harmonisation effects.
Dynamics control was available via compressor and ADR noise gate programs, while the Reverb & Gate algorithm combined ambience with precise gating for percussive sources. The onboard parametric equaliser enabled precise tonal shaping with control over centre frequency, bandwidth, and gain across low, mid, and high bands.
Front-panel operation was intuitive, with a high-contrast two-line LCD displaying program names and parameters, a dedicated LED numeric display for memory locations, and a 7-point input level meter. Keys allowed quick navigation, parameter adjustment, direct/effect balance control, program storage, and recall.
The Yamaha SPX90II was fully MIDI compatible, supporting program change, parameter control, and triggering of certain effects such as Freeze and Gate via a footswitch or MIDI. Connectivity included unbalanced ¼-inch input and stereo output jacks, a rear-panel level selector for matching source or line-level devices, and MIDI In/Thru ports for integration with keyboards, sequencers, or other MIDI equipment.
Yamaha promoted the Yamaha SPX90II for a broad range of applications. In live sound, it could be configured for instrument effects, PA enhancement, or as part of a dual-unit system to provide multiple simultaneous effects. In studio settings, it integrated seamlessly with mixing consoles, multitrack recorders, and MIDI rigs.
The Yamaha SPX90II’s compact 480 mm x 45.2 mm x 285 mm rack-mount chassis and light 3.2 kg weight made it equally at home in touring racks or permanent studio installations. With its combination of proven algorithms, increased control ranges, and rock-solid reliability, the Yamaha SPX90II ensured the Yamaha SPX series remained the standard by which other multi-effects units were judged.
Features
- 30 factory preset programs, each with up to nine editable parameters
- 60 RAM user memories for storing custom programs with titles
- Extended control ranges across programs for broader sound design
- Natural reverbs with adjustable decay, pre‑delay, filtering, and room size
- Early Reflections for realistic ambience and added presence
- Independently variable left and right delays, up to two seconds maximum
- Modulation effects including stereo flange, chorus, stereo phasing, tremolo, vibrato, and symphonic
- Reverb & Gate program for precise percussive effects
- Freeze programs with up to two seconds sampling, editable start and end points, and pitch‑change playback
- Pitch Change with one‑cent resolution over a two‑octave range and optional feedback
- ADR Noise Gate with signal‑level triggering and footswitch capability
- Compressor for level control, sustain, and smoothing of instrument dynamics
- Parametric EQ with adjustable low, mid, and high bands
- Two‑line LCD, numeric memory display, and seven‑point input level meter
- Front‑panel keys for parameter editing, balance/output level, store/recall, utility, foot trigger, and bypass
- MIDI In/Thru for program selection and control, plus footswitch triggering for selected programs
- Unbalanced input and stereo outputs with rear‑panel level selectors for sensitivity matching
- Optional RC7 remote controller and MFC1 MIDI foot controller
- Quiet, efficient digital circuitry suitable for stage and studio applications
- Compact 1U rack format for easy integration into any rig
