Niviem Filter S/H

User Manual · Version 1.0

Introduction

NIVIEM Filter S/H is a digital emulation inspired by vintage filter sample/hold effects from the early 1970s — pioneering units that combined state variable filters with LFO and random voltage modulation.

Key Features

  • Two Authentic Modes: Filter (continuous LFO sweep) and Sample/Hold (random stepped modulation)
  • State Variable Filter: True 12dB/octave state variable filter with TPT topology
  • OTA-Style Character: Authentic soft saturation modeling vintage operational transconductance amplifiers
  • Authentic Noise Generator: Gaussian distribution noise modeling avalanche transistor behavior
  • Tempo Sync: Lock LFO rate to host tempo with note divisions
  • Filter Type Selection: LP, BP, HP, Notch, and Peak filter outputs
  • Dry/Wet Mix: Parallel processing capability for modern production
  • Real-Time Safe DSP: XOR-shift PRNG and fast math approximations
  • Preset System: Factory presets + save/load/delete user presets
  • Premium UI: WebView interface with value readouts and rate LED

Historical Background

The Filter Sample/Hold Effect

The Filter Sample/Hold effect emerged in the early 1970s as one of the first commercially available filter modulation effects for guitar. These pioneering effects combined:

  • State Variable Filters: Discrete transistor bandpass/lowpass filters
  • LFO Modulation: Automatic filter sweeping for "auto-wah" effects
  • Sample/Hold Circuit: Random voltage sampling for "computer music" bleeps

The Designer's Legacy

The original filter sample/hold effects were designed by engineers who went on to create legendary synthesizers. The filter topology directly influenced famous synthesizer designs known for their musical character and non-self-oscillating resonance.

Notable Users

  • Frank Zappa - Used for experimental guitar textures
  • Jerry Garcia (Grateful Dead) - Studio work and exploration
  • Prog Rock Artists - Essential tool for the experimental sound of the 1970s

The Filter Sample/Hold Concept

These effects introduced two revolutionary modes in one unit:

Filter Mode: A low-frequency oscillator (LFO) continuously sweeps the filter cutoff frequency, creating the classic "auto-wah" or "filter envelope" effect.

Sample/Hold Mode: A noise transistor generates random voltages that are "sampled" at the LFO rate, creating the iconic "random bleeps and bloops" effect popularized in synthesizer music.

Installation

System Requirements

  • macOS: 11.0 or later (Intel and Apple Silicon native)
  • Windows: Windows 10/11 (64-bit)
  • Plugin Formats: AU, VST3
  • DAW: Any AU/VST3 compatible host (Logic Pro, Ableton Live, Pro Tools, etc.)

Installation Locations

After installation, the plugin files are located at:

macOS:

  • AU: ~/Library/Audio/Plug-Ins/Components/Niviem FSH-1.component
  • VST3: ~/Library/Audio/Plug-Ins/VST3/Niviem FSH-1.vst3

Windows:

  • VST3: C:\Program Files\Common Files\VST3\Niviem FSH-1.vst3

First Launch

  1. Open your DAW
  2. Rescan plugins if necessary
  3. Insert "Niviem FSH-1" on an audio track
  4. The plugin will appear with default Filter mode settings

Quick Start

Getting That Classic Sound

  1. Insert the plugin on your guitar, bass, or synth track
  2. Set Mode to Filter for classic auto-wah sweeps
  3. Adjust Speed to taste (1-3 Hz for classic wah, faster for tremolo-like effects)
  4. Set Range to the center frequency (500-1500 Hz for guitar)
  5. Turn Resonance up for more pronounced filter peaks
  6. Play dynamically - the effect responds to your input signal

Instant Presets

StyleModeSpeedRangeResonanceMix
Classic Auto-WahFilter2 Hz800 HzQ 3.0100%
Slow SweepFilter0.3 Hz500 HzQ 2.0100%
Random BleepsS/H4 Hz1000 HzQ 5.0100%
Synth BubblesS/H8 Hz1500 HzQ 4.0100%
Subtle MovementFilter0.5 Hz600 HzQ 1.570%
Aggressive FilterFilter5 Hz1200 HzQ 7.0100%

Tip: Use the built-in Preset dropdown to access factory presets, or save your own!

Controls: Mode Switch

Options: Filter / Sample-Hold

Selects the modulation source for the filter cutoff frequency.

Filter Mode

  • LFO directly modulates the filter cutoff
  • Creates smooth, continuous sweeps
  • Classic auto-wah and phaser-like effects
  • Triangle waveform for symmetric up/down sweeps

Sample/Hold Mode

  • Random voltages sampled at LFO rate
  • Creates stepped, robotic filter changes
  • Iconic "computer bleeps" effect from 1970s sci-fi
  • Gaussian noise distribution for authentic randomness

Controls: Speed

Range: 0.05 Hz - 15 Hz Default: 1.0 Hz

Controls the LFO/sample rate. This determines how fast the filter sweeps (Filter mode) or how often a new random value is sampled (S/H mode).

SpeedCharacter
0.05-0.5 HzSlow, evolving textures
0.5-2 HzClassic auto-wah range
2-5 HzFast filter sweeps
5-15 HzTremolo-like, extreme effects

Tip: The Rate LED pulses in sync with the LFO for visual feedback.

Controls: Range

Range: 80 Hz - 3000 Hz Default: 500 Hz

Sets the center frequency around which the filter sweeps. The actual cutoff modulates ±2 octaves from this center point.

RangeBest For
80-200 HzBass, low-end textures
200-800 HzGuitar, full-range sweeps
800-1500 HzBright, vocal-like wah
1500-3000 HzTreble emphasis, synth leads

Note: The maximum cutoff is limited to maintain authentic OTA character.

Controls: Resonance

Range: Q 0.5 - 10.0 Default: Q 0.707 (Butterworth)

Controls the filter's resonance (Q factor). Higher values create a more pronounced peak at the cutoff frequency.

Q ValueCharacter
0.5-1.0Subtle, warm filtering
1.0-3.0Musical, vocal-like sweep
3.0-6.0Pronounced, synth-like
6.0-10.0Aggressive, near self-oscillation

Authentic Detail: The state variable filter design does NOT self-oscillate, unlike Moog-style filters. Maximum Q produces strong resonance without becoming a sine wave oscillator.

Frequency-Dependent Q: At high frequencies (>1 kHz), the effective Q is automatically reduced to emulate the natural bandwidth limitations of vintage OTAs.

Controls: Mix (Dry/Wet)

Range: 0% - 100% Default: 100% (full wet)

Blends the processed filter signal with the dry input signal.

MixResult
0%Completely dry (bypass)
50%Equal blend of dry and filtered
100%Full filter effect (authentic)

Use Cases:

  • Parallel Filtering: 30-50% mix preserves low-end and pick attack
  • Bass: 40-60% mix maintains fundamental while adding movement
  • Subtle Enhancement: 70-80% mix for gentle animation

Controls: Tempo Sync

Options: Off, 4 Bars, 2 Bars, 1 Bar, 1/2, 1/4, 1/8, 1/16 Default: Off (free-running)

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

DivisionAt 120 BPM
4 Bars0.125 Hz (8 seconds per cycle)
2 Bars0.25 Hz (4 seconds)
1 Bar0.5 Hz (2 seconds)
1/21 Hz (1 second)
1/42 Hz (quarter note)
1/84 Hz (eighth note)
1/168 Hz (sixteenth note)

Tip: Use "Off" for organic, free-running effects. Use tempo sync for rhythmic, locked filter patterns.

Controls: Filter Type

Options: LP, BP, HP, Notch, Peak Default: LP (Lowpass)

Selects which output of the state variable filter is used.

TypeCharacter
LP (Lowpass)Classic, removes highs - authentic vintage character
BP (Bandpass)Vocal, nasal, focused mid-peak
HP (Highpass)Thin, removes lows, subtle movement
NotchRemoves resonant frequency, phaser-like
PeakBoosts resonant frequency, EQ-like

Historical Note: Original vintage units typically only had lowpass output. Additional modes are provided for modern versatility.

Preset System

Factory Presets

The plugin includes professionally designed factory presets accessible via the Preset dropdown:

  • Classic Auto-Wah - Iconic 1970s filter sweep
  • Slow Evolve - Ambient, gradual movement
  • Random Bleeps - Signature S/H computer sounds
  • Synth Bubbles - Fast S/H with high resonance
  • Bass Filter - Low-range sweep for bass
  • Envelope Follower - Fast modulation, touch-sensitive feel
  • Underwater - Slow, deep sweeps with resonance
  • Robot Voice - S/H vocal-like processing

User Presets

Saving a Preset

  1. Dial in your desired settings
  2. Click the + button in the header
  3. Enter a name for your preset
  4. Click Save

Loading a Preset

  1. Click the Preset dropdown
  2. Select from Factory or User presets

Deleting a User Preset

  1. Open the Preset dropdown
  2. Hover over the user preset you want to delete
  3. Click the X button that appears
  4. Preset is deleted immediately

Note: Factory presets cannot be deleted or overwritten.

Operating Modes

Filter Mode - Continuous Sweep

In Filter mode, a triangle-wave LFO continuously modulates the filter cutoff frequency. This creates the classic "auto-wah" effect heard on countless recordings.

Signal Flow:

Input → OTA SVF → [Cutoff modulated by Triangle LFO] → Output

LFO Characteristics:

  • Triangle waveform (symmetric rise/fall)
  • Rate controlled by Speed parameter
  • Modulation depth: ±2 octaves from Range center
  • Rate ramping for smooth speed changes

Sample/Hold Mode - Stepped Random

In Sample/Hold mode, random voltages are "sampled" at the LFO rate, creating stepped filter changes. This is the iconic "computer music" effect.

Signal Flow:

Input → OTA SVF → [Cutoff modulated by S/H random] → Output
                              ↑
                    Noise → Sample at LFO rate

S/H Characteristics:

  • Gaussian noise (authentic avalanche transistor behavior)
  • Sampled at Speed rate
  • Slew-rate limiting for slightly smoothed steps
  • Optional droop emulation (capacitor leakage)

Technical Authenticity

State Variable Filter (SVF)

The NIVIEM Filter S/H uses a Topology-Preserving Transform (TPT) implementation of the state variable filter, based on Vadim Zavalishin's "The Art of VA Filter Design."

TPT Advantages

  • Zero-delay feedback topology
  • Correct resonance behavior at all frequencies
  • Stable at high Q values
  • Frequency-accurate even near Nyquist

Vintage SVF Characteristics

  • 12dB/octave slope (2-pole)
  • Non-self-oscillating resonance
  • Musical, vocal-like character
  • Warm, analog-sounding

OTA Emulation

Vintage filter effects used Operational Transconductance Amplifiers. We emulate their characteristics:

Saturation Modeling

  • tanh-based soft clipping
  • 2x oversampling to prevent aliasing
  • Authentic thermal voltage threshold
  • Frequency-dependent Q reduction at high frequencies

Noise Generation

The S/H mode uses authentic avalanche noise characteristics:

Transistor Noise Modeling

  • Gaussian distribution (authentic avalanche breakdown)
  • Real-time safe XOR-shift PRNG
  • Box-Muller transform for proper distribution
  • Bandwidth-limited for correlated noise

Usage Tips

Guitar

  • Classic Rock: Filter mode, 1-2 Hz, Range 600-1000 Hz, Q 2.0-3.0
  • Funk Wah: Filter mode, 2-4 Hz, Range 800-1200 Hz, Q 4.0-6.0
  • Ambient Textures: Filter mode, 0.1-0.3 Hz, Range 400-800 Hz, Q 1.5-2.0
  • Sci-Fi Leads: S/H mode, 3-8 Hz, Range 800-1500 Hz, Q 5.0-8.0

Bass

  • Subtle Movement: Filter mode, 0.3-0.8 Hz, Range 150-400 Hz, Q 1.0-2.0, Mix 60%
  • Synth Bass: S/H mode, 2-4 Hz, Range 200-600 Hz, Q 3.0-4.0, Mix 80%
  • Envelope Effect: Filter mode, 3-6 Hz, Range 300-600 Hz, Q 2.5-3.5

Synthesizers

  • Classic Analog: Filter mode, 0.5-2 Hz, Range 500-1500 Hz, Q 3.0-6.0
  • Random Arps: S/H mode, tempo-synced to 1/8 or 1/16, Q 4.0-7.0
  • Pad Animation: Filter mode, 0.1-0.3 Hz, Range 300-800 Hz, Q 1.0-2.0

Mixing Tips

  • Parallel Processing: Use 40-60% mix to maintain fundamental while adding movement
  • Automation: Automate Speed for buildups and breakdowns
  • Tempo Sync: Lock to 1/4 or 1/8 notes for rhythmic filtering
  • Resonance Ducking: Higher Q values can boost specific frequencies - adjust output level

Technical Specifications

Audio

ParameterValue
Sample Rates44.1kHz - 192kHz
Internal Processing32-bit floating point
Oversampling2x (saturation only)
Latency< 1ms
Filter TopologyTPT State Variable (Zavalishin)

Plugin

ParameterValue
FormatsAU, VST3
PlatformmacOS 11.0+, Windows 10/11
ArchitectureUniversal (Intel + Apple Silicon), x64
UIWebView (400x580)
Preset SystemFactory + User presets

Parameters

ParameterRangeDefault
BypassOn/OffOff
ModeFilter/S-HFilter
Speed0.05-15 Hz1.0 Hz
Range80-3000 Hz500 Hz
ResonanceQ 0.5-10Q 0.707
Mix0-100%100%
Tempo SyncOff/4 Bar-1/16Off
Filter TypeLP/BP/HP/Notch/PeakLP

Troubleshooting

No Sound

  1. Check that Bypass is OFF
  2. Ensure Mix is above 0%
  3. Verify your DAW routing
  4. Check input signal is present

No Filter Effect Audible

  1. Increase Resonance to make the sweep more pronounced
  2. Adjust Range to center on your audio's frequency content
  3. Verify Speed is within audible range (0.1-10 Hz)
  4. Switch Filter Type to LP if using other modes

Sound is Too Harsh

  1. Reduce Resonance (Q)
  2. Lower the Range parameter
  3. Try Filter Type: LP instead of BP or HP
  4. Reduce Mix for more dry signal

LFO Not Syncing to Tempo

  1. Ensure Tempo Sync is not set to "Off"
  2. Check that your DAW is sending tempo information
  3. Restart playback to resync

Plugin Not Appearing in DAW

  1. Verify installation location
  2. Rescan plugins in your DAW
  3. Check plugin format compatibility (AU vs VST3)
  4. Restart your DAW

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

Credits & References

Development

NIVIEM Filter S/H was developed by Milan Vasiljev / NIVIEM with a commitment to authentic, component-accurate vintage effect emulation.

Technical References

  • Vadim Zavalishin - "The Art of VA Filter Design" (Native Instruments)
  • OTA Application Notes and Datasheets
  • Transistor Noise Specifications

Special Thanks

  • The DIY pedal building community for preserving vintage circuit knowledge
  • All the engineers who pioneered filter modulation effects in the 1970s

Version History

VersionDateChanges
1.0Dec 2025Initial release with full DSP implementation, preset system, License Manager, and WebView UI

NIVIEM Filter S/H Authentic Vintage Filter Modulation, Reimagined


Trademark Notice

NIVIEM Filter S/H is an independent product developed by NIVIEM. This plugin is inspired by vintage filter sample/hold effects from the 1970s and is designed to emulate their sound characteristics.

This product is not affiliated with, endorsed by, or sponsored by any manufacturer of vintage audio equipment. All product names, trademarks, and registered trademarks mentioned in this documentation are the property of their respective owners.

The use of historical references 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.


Copyright 2025 Milan Vasiljev. All Rights Reserved.

NIVIEM is a trademark of Milan Vasiljev.

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