The Lexicon PCM 70 Digital Effects Processor was introduced in 1985 as a compact single-space rackmount unit designed to deliver the same class of digital effects heard in leading professional studios. Positioned as an accessible entry into Lexicon’s high-end processing heritage, the Lexicon PCM 70 combined advanced reverb design with extensive programmability and forward-thinking MIDI control in a format suited to both studio and stage environments.
The Lexicon PCM 70 provided more than 40 factory digital effects and reverb programs, covering chorus and echo, resonant chords, multiband delays, rich chamber, rich plate, and concert hall algorithms. In addition to the preset library, the Lexicon PCM 70 allowed users to create and store 50 custom programs in user registers, giving immediate access to more than 90 total programs. This structure enabled engineers and musicians to move seamlessly between established Lexicon spaces and highly personalised treatments tailored to specific sessions.
Editing depth was central to the Lexicon PCM 70 design. More than 70 different parameter types could be adjusted, including delay times, feedback, filtering, panning, and early reflections. This level of control allowed the Lexicon PCM 70 to move beyond static ambience and into detailed spatial design, where modulation, diffusion, and timing could be shaped precisely for each source.
A defining feature of the Lexicon PCM 70 was its implementation of Dynamic MIDI. This system enabled real-time remote control of up to ten parameters simultaneously from a MIDI keyboard or sequencer. Any effect or reverb parameter could be assigned to variable MIDI controllers such as modulation wheel, pitch wheel, data slider, sustain switch, or other assignable controls. Parameters could also respond directly to MIDI performance data including key velocity, pressure, and aftertouch, allowing expressive, performance-based manipulation of reverb and delay characteristics.
When used with a sequencer, control changes transmitted to the Lexicon PCM 70 could be recorded and replayed accurately, ensuring repeatable automation of effects movements. A complementary register feature allowed remote program selection from sequencers, synthesisers, and other MIDI devices, integrating the Lexicon PCM 70 directly into evolving MIDI production workflows of the mid-1980s. The user interface was designed to make this functionality accessible, enabling rapid navigation of programs and parameters despite the unit’s depth.
While the Lexicon PCM 70 was positioned above many budget digital processors of its era, including the widely adopted Yamaha SPX90, it established itself in professional studios through its distinctive algorithm design, programmability, and comprehensive MIDI integration. The Lexicon PCM 70 became a fixture in music production throughout the late 1980s and early 1990s, valued for its flexible spatial effects and its ability to bridge performance control with studio precision.
Features
- Single-space rackmount digital effects processor
- More than 40 factory digital effects and reverb programs
- Chorus, echo, resonant chords, multiband delays, rich chamber, rich plate, and concert hall algorithms
- 50 user-programmable registers
- Access to more than 90 total programs
- More than 70 editable parameter types
- Adjustable delay times, feedback, filters, panning, and early reflections
- Dynamic MIDI real-time parameter control
- Simultaneous control of up to ten parameters via MIDI
- Assignable control from modulation wheel, pitch wheel, data slider, sustain switch, and other MIDI controllers
- Parameter response to velocity, pressure, and aftertouch
- Remote program selection via MIDI
- Recordable and repeatable MIDI control changes via sequencer
- Integrated and accessible user interface design
