Niviem Phase One

NIVIEM Phase One is a detailed digital emulation inspired by the legendary Maestro PS-1A Phase Shifter (1971), designed by Tom Oberheim and manufactured by Gibson/Maestro. The PS-1A was one of the first commercially available phaser pedals and became a defining sound of 1970s music.

What Makes This Plugin Special

• Authentic to the Core: Vintage Mode uses the exact same DSP code as the original PS-1A - no shortcuts, no compromises
• True 6-Stage All-Pass Cascade: Creates 3 sweeping notches for rich, complex phasing
• Three Speed Presets: Slow (0.5 Hz), Medium (1.0 Hz), and Fast (6.0 Hz) - matching the original
• Leslie-Style Speed Ramping: Smooth acceleration and deceleration when switching speeds
• Vintage Mode: Locks to 100% authentic PS-1A behavior with no modern additions
• Modern Mode: Adds Depth control and Tempo Sync while preserving the classic sound
• Zero-Latency Processing: Real-time performance with no perceptible delay
• Premium DSP Quality: 64-bit coefficient calculations, DC blocking, denormal prevention
• Authentic WebView UI: Period-accurate interface inspired by 1970s Lowrey organ buttons

Historical Context

The Maestro PS-1 Phase Shifter was born from Tom Oberheim's desire to electronically simulate the sound of a Leslie rotating speaker cabinet. While the Leslie creates its distinctive sound through physical rotation of horn and drum assemblies, Oberheim realized he could approximate this effect using phase-shifting circuits.

The PS-1 debuted in 1971, with the refined PS-1A appearing in early 1972. It quickly became a studio staple and can be heard on countless classic recordings.

Design Philosophy

Tom Oberheim chose a 6-stage all-pass filter topology because it creates 3 notches in the frequency spectrum - enough for a rich, complex phasing effect without becoming muddy or metallic. The three preset speeds were carefully chosen to provide musically useful rates:

• Slow: A gentle, breathing 2-second sweep
• Medium: The classic 1-second phaser pulse
• Fast: A vibrato-like warble effect

The Leslie-style speed ramping was a stroke of genius - instead of jarring instant speed changes, the LFO smoothly accelerates or decelerates, just like a real rotating speaker taking time to speed up or slow down.

Notable Users

The PS-1A's distinctive sound was embraced by many legendary artists:

• John Paul Jones (Led Zeppelin) - The ethereal keyboards on "No Quarter"
• George Harrison (The Beatles) - "This Guitar (Can't Keep From Crying)"
• Ernie Isley (Isley Brothers) - The iconic phased guitar on "That Lady" (1973)
• Steve Howe (Yes) - Progressive rock guitar textures
• Alex Lifeson (Rush) - Phased rhythm guitar tones
• Waylon Jennings - Outlaw country phaser tones
• Martin Gore (Depeche Mode) - Synth textures

Original Hardware Specifications

Our Approach to Emulation

The NIVIEM Phase One was developed using rigorous methodology:

1. Primary Source Analysis: R.G. Keen's traced schematic and technical documentation
2. Reference Verification: Cross-referenced with Patchstorage PS-1A emulation values
3. Component Verification: Period-correct JFET characteristics, op-amp topology
4. Circuit Topology Preservation: Signal flow matches the original exactly
5. Behavioral Accuracy: Each circuit block analyzed and implemented accordingly

Critical Implementation Details

6-Stage All-Pass Filter Cascade

The original PS-1A uses 6 cascaded first-order all-pass filters:

Why 6 Stages?

• Total DC phase shift: 6 × 180° = 1080° = 3 × 360°
• Number of notches: 6 ÷ 2 = 3 notches
• Rich, complex interference patterns
• Not too many stages (which can sound metallic)

Triangle Wave LFO

The PS-1A uses a triangle wave LFO rather than a sine wave:

Triangle Wave Formula:

y(t) = 4·|phase - 0.5| - 1

Leslie-Style Speed Ramping

When switching speeds, the LFO doesn't instantly jump to the new rate:

This creates the same expressive quality as a Leslie speaker's horn speeding up or slowing down.

System Requirements

• Formats: Audio Unit (AU - macOS only), VST3 (macOS & Windows)
• DAW: Logic Pro, GarageBand, Ableton Live, Cubase, Studio One, Reaper, Bitwig, or any AU/VST3 host
• RAM: 4 GB minimum
• Disk Space: ~30 MB

Installation Steps

macOS

1. Download NIVIEM Phase One from the official website
2. Extract the archive
3. Copy the plugins to:
   • AU: ~/Library/Audio/Plug-Ins/Components/Niviem Phase One.component
   • VST3: ~/Library/Audio/Plug-Ins/VST3/Niviem Phase One.vst3
4. Restart your DAW
5. Scan for new plugins if required

Manual Installation (Terminal):

# Copy AU plugin
cp -r "Niviem Phase One.component" ~/Library/Audio/Plug-Ins/Components/

# Copy VST3 plugin
cp -r "Niviem Phase One.vst3" ~/Library/Audio/Plug-Ins/VST3/

Note: The plugin is code-signed and notarized by Apple. If macOS shows a security warning, go to System Settings > Privacy & Security and click "Open Anyway".

Windows

Prerequisites: Windows users must have Microsoft WebView2 Runtime installed. This is pre-installed on Windows 11 and most Windows 10 systems. If needed, download from: https://developer.microsoft.com/en-us/microsoft-edge/webview2/

1. Download NIVIEM Phase One from the official website
2. Extract the archive
3. Copy Niviem Phase One.vst3 to:
   • VST3: C:\Program Files\Common Files\VST3\
4. Restart your DAW
5. Scan for new plugins if required

Note: Windows may show a SmartScreen warning for unsigned software. Click "More info" → "Run anyway" to proceed.

Verifying Installation (macOS)

To verify the AU plugin is correctly installed:

auval -v aufx Nps1 Nivm

You should see "AU VALIDATION SUCCEEDED" at the end of the output.

Quick Start

1. Insert NIVIEM Phase One on an audio track (guitar, keyboards, synths, vocals, etc.)
2. Click one of the three speed buttons: SLOW, MEDIUM, or FAST
3. That's it! The authentic PS-1A phaser sound is now applied to your audio.

Signal Flow

Input Signal → 6-Stage All-Pass Cascade → Mix with Dry → DC Blocking → Output
                        ↑
                   Triangle LFO
                  (Speed Ramping)

The plugin processes your audio through six cascaded first-order all-pass filters. The break frequency of these filters is modulated by a triangle wave LFO, creating the characteristic sweeping effect. The processed (wet) signal is mixed with the dry signal based on the Depth control.

The NIVIEM Phase One interface features a dark industrial chassis with backlit controls and period-accurate Lowrey-style speed buttons.

Layout Organization

┌─────────────────────────────────────────────────────────────────────────┐
│                              HEADER BAR                                  │
│                    [NIVIEM]  PHASE ONE                                   │
├─────────────────────────────────────────────────────────────────────────┤
│                                                                          │
│                         ┌─────────────┐                                  │
│                         │  LFO PANEL  │                                  │
│                         │     ●       │  ← Animated dot (color = speed) │
│                         └─────────────┘                                  │
│                                                                          │
│     ┌─────────┐      ┌─────────┐      ┌─────────┐                       │
│     │  SLOW   │      │ MEDIUM  │      │  FAST   │                       │
│     │ (Blue)  │      │(Yellow) │      │  (Red)  │                       │
│     └─────────┘      └─────────┘      └─────────┘                       │
│                                                                          │
│               ┌─────────────────────────────────┐                        │
│               │         DEPTH KNOB              │                        │
│               │           (●)                   │                        │
│               └─────────────────────────────────┘                        │
│                                                                          │
│     ┌─────────────────┐     ┌─────────────────┐                         │
│     │   SYNC Toggle   │     │ VINTAGE Toggle  │                         │
│     └─────────────────┘     └─────────────────┘                         │
│                                                                          │
├─────────────────────────────────────────────────────────────────────────┤
│                            FOOTER BAR                                    │
│        BYPASS [●]                             Phase One                  │
└─────────────────────────────────────────────────────────────────────────┘

Visual Elements

• LFO Dot: Animated indicator showing LFO position
  • Blue when Slow is selected
  • Yellow when Medium is selected
  • Red when Fast is selected
• Speed Buttons: Backlit glow when active
• Depth Tooltip: Shows exact value (0-100%) on hover
• Bypass LED: Illuminates when effect is active

NIVIEM Phase One offers two operating modes to suit different workflows:

Vintage Mode (Authentic)

When Vintage Mode is enabled:

Use Vintage Mode when:

• You want 100% authentic PS-1A sound
• You're recreating classic recordings
• You need mono compatibility (no phase issues when summed)

Modern Mode (Enhanced)

When Vintage Mode is disabled:

Use Modern Mode when:

• You need more subtle phasing (lower Depth)
• You want tempo-locked LFO for rhythmic effects
• You need smooth parameter automation

Speed Buttons

Click any button to select that speed. The LFO will ramp to the new speed (Leslie-style).

Depth Knob (Modern Mode Only)

Range: 0% - 100% Default: 100%

Controls the wet/dry mix of the phaser effect.

Note: In Vintage Mode, Depth is locked to 100%.

Sync Toggle (Modern Mode Only)

Options: Off / On Default: Off

When enabled, the LFO rate locks to your DAW's tempo:

Note: In Vintage Mode, Sync is disabled.

Vintage Toggle

Options: Off (Modern) / On (Vintage) Default: Off

Switches between Modern and Vintage operating modes. See Operating Modes for details.

Bypass

Options: Off / On Default: Off

• Vintage Mode: Instant pass-through (no crossfade)
• Modern Mode: Smooth crossfade bypass

SLOW (Blue Button) - 0.5 Hz

The Slow setting creates a gentle, breathing effect with a full sweep taking approximately 2 seconds.

Best for:

• Subtle pad and ambient textures
• Slow, emotional ballads
• Adding gentle movement to sustained chords
• Classic 70s keyboard sounds

Character:

• Relaxed, meditative quality
• Notches sweep slowly through the spectrum
• Adds depth without being distracting

MEDIUM (Yellow Button) - 1.0 Hz

The Medium setting is the "classic" phaser sound - a balanced 1-second sweep that works in almost any context.

Best for:

• Classic rock guitar rhythm parts
• Funk and R&B rhythm guitar
• Keyboard textures
• General-purpose phasing

Character:

• The quintessential phaser sound
• Musical and versatile
• Works with most tempos (60-120 BPM)

FAST (Red Button) - 6.0 Hz

The Fast setting creates a vibrato-like warble effect, with the sweep completing approximately 6 times per second.

Best for:

• Vibrato-style effects on guitar or keys
• Psychedelic and experimental textures
• Creating tension and urgency
• Special effects and transitions

Character:

• Intense, almost tremolo-like
• Creates a shimmer or wobble
• Best used sparingly for dramatic effect

Speed Ramping Behavior

One of the most distinctive features of the PS-1A is its Leslie-style speed ramping. When you switch between speeds:

1. The LFO doesn't instantly jump to the new rate
2. Instead, it smoothly accelerates or decelerates
3. The time constant is approximately 0.5 seconds
4. After about 1.5 seconds, the new speed is reached

This creates the same expressive quality as a Leslie speaker's horn speeding up or slowing down. Use this musically:

• Switch from SLOW to FAST right before a chorus for a dramatic build
• Switch from FAST to SLOW at the end of a section for a "winding down" effect
• Automate speed changes in your DAW for evolving textures

Classic 70s Phaser Guitar

1. Enable Vintage Mode
2. Set speed to MEDIUM
3. Use a clean or slightly overdriven guitar tone
4. Play rhythm chords with light strumming
5. The phaser adds movement without overwhelming the fundamental tone

"That Lady" Guitar Sound

To recreate Ernie Isley's iconic phased guitar tone:

1. Enable Vintage Mode
2. Use a humbucker guitar with moderate overdrive
3. Set speed to MEDIUM
4. Play funky rhythmic patterns
5. Let the phaser sweep interact with your playing dynamics

Ethereal Keyboard Pads

1. Enable Vintage Mode
2. Set speed to SLOW
3. Apply to electric piano, organ, or synthesizer pads
4. Use sustained chords
5. The gentle sweep adds dimension and life to static sounds

Vibrato Effect

1. Enable Vintage Mode
2. Set speed to FAST
3. Works especially well on single-note lines
4. Creates a shimmering, pitch-modulation-like effect
5. Good for psychedelic leads

Subtle Modern Phasing

1. Disable Vintage Mode
2. Set Depth to 30-50%
3. Set speed to SLOW or MEDIUM
4. Great for adding gentle movement without obvious phasing
5. Works well on vocals and acoustic instruments

Tempo-Synced Effects

1. Disable Vintage Mode
2. Enable Sync
3. Choose speed based on desired rhythmic division
4. Great for electronic and modern productions
5. LFO stays locked to song tempo changes

Automated Speed Changes

In your DAW, automate the speed parameter for evolving effects:

Verse:      SLOW (0)
Pre-Chorus: MEDIUM (1) - automation point
Chorus:     FAST (2) - automation point

The smooth ramping makes these transitions musical rather than jarring.

Stereo Enhancement

NIVIEM Phase One applies the same modulation to both channels (mono-compatible). This means:

• No phase issues when summed to mono
• Consistent phasing across the stereo field
• Perfect for broadcasts and mono playback systems

User-Adjustable Parameters

Internal Parameters

Audio

Filter

LFO

Processing Quality

How Phase Shifters Work

A phaser works by splitting the audio signal into two paths:

1. Dry Path: The original signal passes through unchanged
2. Wet Path: The signal passes through all-pass filters that shift phase

When these paths are recombined, frequencies where the phase shift equals 180° (plus multiples of 360°) experience destructive interference, creating notches in the frequency spectrum.

All-Pass Filters

Unlike low-pass or high-pass filters, all-pass filters pass all frequencies with unity gain but introduce a frequency-dependent phase shift.

First-Order All-Pass Transfer Function:

        s - ωb
H(s) = ───────
        s + ωb

Where ωb is the "break" or "corner" frequency.

Phase Response:

φ(ω) = π - 2·arctan(ω/ωb)

• At DC (ω = 0): Phase shift = 180°
• At break frequency (ω = ωb): Phase shift = 90°
• At high frequency (ω → ∞): Phase shift = 0°

Logarithmic Frequency Mapping

The break frequency is swept using logarithmic interpolation:

breakFreq = minFreq × (maxFreq / minFreq)^normalized

Where normalized is the LFO output mapped from [-1, +1] to [0, 1].

This is perceptually linear because human hearing perceives frequency logarithmically (each octave is a doubling of frequency).

Notch Generation

When dry and wet signals are mixed 1:1, notches occur where:

Total Phase Shift = 180° + n × 360°  (where n = 0, 1, 2, ...)

As the LFO sweeps the break frequency, these notches move through the spectrum, creating the characteristic "swooshing" sound.

Plugin Not Appearing in DAW

1. Verify the plugin is in the correct folder:
   • AU: ~/Library/Audio/Plug-Ins/Components/
   • VST3: ~/Library/Audio/Plug-Ins/VST3/
2. Rescan plugins in your DAW preferences
3. On macOS, check System Preferences > Security & Privacy if the plugin is blocked
4. Run auval -v aufx Nps1 Nivm to verify AU installation

No Audible Effect

1. Ensure the plugin is not bypassed
2. Verify input signal is present (check input meter in DAW)
3. Check that the track is not muted
4. Check Depth is above 0% (Modern mode)
5. The phaser effect is subtle at some speeds - try FAST for the most obvious effect

Effect Sounds Wrong

1. Ensure the source material has frequency content in the sweep range (20 Hz - 5 kHz)
2. Very dark or very bright sources may not phase effectively
3. The effect is most obvious on harmonically rich material (distorted guitar, organ, etc.)
4. Try enabling Vintage Mode for authentic PS-1A behavior

Speed Changes Feel Instant

The PS-1A should have smooth speed ramping. If speeds change instantly:

1. Ensure you have the latest version of the plugin
2. The ramping time is approximately 1.5 seconds to reach 95% of target

CPU Usage Too High

The NIVIEM Phase One is highly optimized and should have minimal CPU impact. If experiencing high CPU:

1. Check that you don't have hundreds of instances
2. Increase your DAW's buffer size
3. Disable other heavy plugins to isolate the issue

Clicks or Pops

1. Increase your DAW's buffer size (try 256 or 512 samples)
2. In Modern mode, parameter smoothing should prevent clicks
3. In Vintage mode, rapid parameter changes may cause artifacts (authentic behavior)
4. Check for automation discontinuities

Windows: WebView2 Required

If you see a message about WebView2:

1. Download Microsoft WebView2 Runtime from: https://developer.microsoft.com/en-us/microsoft-edge/webview2/
2. Install and restart your DAW

Development

Developed by Milan Vasiljev / NIVIEM

Primary Research Sources

1. R.G. Keen - GeoFEX

   • Traced Maestro PS-1A schematic
   • Technical documentation and analysis
   • geofex.com

2. Patchstorage

   • PS-1A/PS-1B reference measurements
   • LFO rate verification
   • patchstorage.com

3. FreestompBoxes.org

   • Circuit analysis and discussion
   • Component verification
   • freestompboxes.org

4. David Morrin

   • PS-1 technical notes
   • JFET specifications

Technical References

• Vadim Zavalishin - "The Art of VA Filter Design" (filter theory)
• CCRMA Stanford - Phase shifter theory
• WolfSound - All-pass filter mathematics

Special Thanks

To Tom Oberheim for the original PS-1A design that revolutionized guitar effects.

To the countless artists who made the phaser a staple of recorded music.

To the vintage gear community for preserving these classic sounds and sharing knowledge.

Version 1.0 (January 2026)

• Initial release
• Dual Operating Modes:
  • Vintage Mode: 100% authentic PS-1A processing
  • Modern Mode: Enhanced with Depth and Tempo Sync
• Authentic 6-stage all-pass filter cascade
• Three speed presets (Slow/Medium/Fast)
• Leslie-style speed ramping
• Stereo processing with mono compatibility
• Premium DSP quality:
  • 64-bit coefficient calculations
  • DC blocking on output
  • Denormal prevention
  • Parameter smoothing (Modern mode)
  • Click-free bypass crossfade (Modern mode)
• WebView-based authentic UI:
  • Lowrey-style speed buttons with glow
  • Animated LFO indicator (color-coded)
  • Depth tooltip on hover
  • Full keyboard accessibility (Tab + Arrow keys)
  • WCAG AA contrast compliance

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Copyright 2026 Milan Vasiljev. All Rights Reserved.

NIVIEM is a trademark of Milan Vasiljev.

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Trademark Notice

NIVIEM Phase One is an independent product developed by NIVIEM. This plugin is inspired by the vintage Maestro PS-1A Phase Shifter (1971) and is designed to emulate its sound characteristics.

Maestro is a registered trademark of Gibson Brands, Inc. The original PS-1A Phase Shifter was a product of Gibson/Maestro, designed by Tom Oberheim.

This product is not affiliated with, endorsed by, or sponsored by Gibson Brands, Inc. or any of their affiliates. All product names, trademarks, and registered trademarks mentioned in this documentation are the property of their respective owners.

The use of these names is solely for the purpose of describing the sound characteristics and historical context that inspired this emulation, which is standard practice in the audio software industry.

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For support: milan.vasiljev.work@gmail.com