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
- Open your DAW
- Rescan plugins if necessary
- Insert "Niviem FSH-1" on an audio track
- The plugin will appear with default Filter mode settings
Quick Start
Getting That Classic Sound
- Insert the plugin on your guitar, bass, or synth track
- Set Mode to Filter for classic auto-wah sweeps
- Adjust Speed to taste (1-3 Hz for classic wah, faster for tremolo-like effects)
- Set Range to the center frequency (500-1500 Hz for guitar)
- Turn Resonance up for more pronounced filter peaks
- Play dynamically - the effect responds to your input signal
Instant Presets
| Style | Mode | Speed | Range | Resonance | Mix |
|---|---|---|---|---|---|
| Classic Auto-Wah | Filter | 2 Hz | 800 Hz | Q 3.0 | 100% |
| Slow Sweep | Filter | 0.3 Hz | 500 Hz | Q 2.0 | 100% |
| Random Bleeps | S/H | 4 Hz | 1000 Hz | Q 5.0 | 100% |
| Synth Bubbles | S/H | 8 Hz | 1500 Hz | Q 4.0 | 100% |
| Subtle Movement | Filter | 0.5 Hz | 600 Hz | Q 1.5 | 70% |
| Aggressive Filter | Filter | 5 Hz | 1200 Hz | Q 7.0 | 100% |
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).
| Speed | Character |
|---|---|
| 0.05-0.5 Hz | Slow, evolving textures |
| 0.5-2 Hz | Classic auto-wah range |
| 2-5 Hz | Fast filter sweeps |
| 5-15 Hz | Tremolo-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.
| Range | Best For |
|---|---|
| 80-200 Hz | Bass, low-end textures |
| 200-800 Hz | Guitar, full-range sweeps |
| 800-1500 Hz | Bright, vocal-like wah |
| 1500-3000 Hz | Treble 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 Value | Character |
|---|---|
| 0.5-1.0 | Subtle, warm filtering |
| 1.0-3.0 | Musical, vocal-like sweep |
| 3.0-6.0 | Pronounced, synth-like |
| 6.0-10.0 | Aggressive, 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.
| Mix | Result |
|---|---|
| 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.
| Division | At 120 BPM |
|---|---|
| 4 Bars | 0.125 Hz (8 seconds per cycle) |
| 2 Bars | 0.25 Hz (4 seconds) |
| 1 Bar | 0.5 Hz (2 seconds) |
| 1/2 | 1 Hz (1 second) |
| 1/4 | 2 Hz (quarter note) |
| 1/8 | 4 Hz (eighth note) |
| 1/16 | 8 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.
| Type | Character |
|---|---|
| LP (Lowpass) | Classic, removes highs - authentic vintage character |
| BP (Bandpass) | Vocal, nasal, focused mid-peak |
| HP (Highpass) | Thin, removes lows, subtle movement |
| Notch | Removes resonant frequency, phaser-like |
| Peak | Boosts 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
- Dial in your desired settings
- Click the + button in the header
- Enter a name for your preset
- Click Save
Loading a Preset
- Click the Preset dropdown
- Select from Factory or User presets
Deleting a User Preset
- Open the Preset dropdown
- Hover over the user preset you want to delete
- Click the X button that appears
- 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
| Parameter | Value |
|---|---|
| Sample Rates | 44.1kHz - 192kHz |
| Internal Processing | 32-bit floating point |
| Oversampling | 2x (saturation only) |
| Latency | < 1ms |
| Filter Topology | TPT State Variable (Zavalishin) |
Plugin
| Parameter | Value |
|---|---|
| Formats | AU, VST3 |
| Platform | macOS 11.0+, Windows 10/11 |
| Architecture | Universal (Intel + Apple Silicon), x64 |
| UI | WebView (400x580) |
| Preset System | Factory + User presets |
Parameters
| Parameter | Range | Default |
|---|---|---|
| Bypass | On/Off | Off |
| Mode | Filter/S-H | Filter |
| Speed | 0.05-15 Hz | 1.0 Hz |
| Range | 80-3000 Hz | 500 Hz |
| Resonance | Q 0.5-10 | Q 0.707 |
| Mix | 0-100% | 100% |
| Tempo Sync | Off/4 Bar-1/16 | Off |
| Filter Type | LP/BP/HP/Notch/Peak | LP |
Troubleshooting
No Sound
- Check that Bypass is OFF
- Ensure Mix is above 0%
- Verify your DAW routing
- Check input signal is present
No Filter Effect Audible
- Increase Resonance to make the sweep more pronounced
- Adjust Range to center on your audio's frequency content
- Verify Speed is within audible range (0.1-10 Hz)
- Switch Filter Type to LP if using other modes
Sound is Too Harsh
- Reduce Resonance (Q)
- Lower the Range parameter
- Try Filter Type: LP instead of BP or HP
- Reduce Mix for more dry signal
LFO Not Syncing to Tempo
- Ensure Tempo Sync is not set to "Off"
- Check that your DAW is sending tempo information
- Restart playback to resync
Plugin Not Appearing in DAW
- Verify installation location
- Rescan plugins in your DAW
- Check plugin format compatibility (AU vs VST3)
- Restart your DAW
Windows: WebView2 Required
If you see a message about WebView2:
- Download Microsoft WebView2 Runtime from: https://developer.microsoft.com/en-us/microsoft-edge/webview2/
- 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
| Version | Date | Changes |
|---|---|---|
| 1.0 | Dec 2025 | Initial 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