Comparison

GSDSP Quantum Filter vs VAPolyQuad

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

GSDSP Quantum Filter

This audio effect plugin offers analog-modeled filters with flexible routing and dynamic modulation for creative sound design. It provides extensive control over tone shaping and complex filtering with various filter types and configurations.

Highlights
  • Analog-modelled filters
  • 11 filter modes
  • Series and parallel routing
  • Dynamic modulation support
  • Stereo and dual mono modes
  • MIDI control integration
Features
Read full description

Analog warmth meets flexible routing and dynamic modulation in a filter workstation built for creative sound design. Analog-Modelled Filters Quantum Filter uses resonant, analog-modelled filter designs that behave smoothly and musically across the entire spectrum. With no cramping, stepping, or digital artefacts, the filters remain stable even under rapid modulation. At high resonance settings they can reach self-oscillation, similar to classic hardware circuits. Filter Types & Routing Choose from 11 filter modes, including Lowpass, Highpass, Bandpass, Notch, Shelving options, Bell, and Ladder Lowpass in 1–4 pole configurations. Combine filters in series (up to three stages) or parallel (up to two), resulting in over 2,000 possible routing combinations for detailed tone shaping and complex layered filtering. Built for Modulation Designed to handle fast, artefact-free modulation, Quantum Filter responds cleanly even under rapid parameter changes. Its stability makes it suitable for dynamic environments, rhythmic modulation, or complex movement across multiple filter stages. Stereo and Dual Mono Switch between stereo and dual mono modes to shape the stereo image. In dual mono mode, left and right channels can move independently, enabling asymmetric movement, wider imaging, or separate modulation paths for each side. MIDI Control Quantum Filter integrates ADSR & AR modulators that respond directly to MIDI, allowing envelope-driven filter motion that behaves like a synthesizer’s filter section. This integration adds expressive control for rhythmic gating, animated sweeps, and dynamic shaping based on your playing or sequencing. Quantum Filter is an AUv3 audio effect plugin compatible with Logic Pro, AUM, Cubasis, GarageBand and many more. A Desktop version is also available for Windows and macOS (VST3 / AU / AAX). More information here: https://gs-dsp.com/products

About

VAPolyQuad

Create rich, analog-style music with this powerful polyphonic synthesizer. Explore a vast array of sound-shaping tools, including multiple oscillators, filters, and effects. Program intricate melodies and rhythms with the built-in sequencer, and seamlessly share projects across your Apple devices.

Highlights
  • Virtual analog polyphonic synthesizer
  • Up to 8 voice polyphony
  • Four oscillators per voice
  • Multiple resonant filters
  • Built-in effects suite
  • 16-bar sequencer with piano roll
  • Audio Unit Extension (AUv3) support
Features
Read full description

VAPolyQuad is a virtual analog polyphonic synthesizer for iPhone, iPad and Mac. It features 8 voice synthesizer, effects, sequencer and audio visualization tools. It operates as a stand alone or as an AudioUnit Extension (AUv3). Stand Alone supports Ableton Link, MIDI and audio file export. Single voice of the synthesizer features four oscillators, two mixers, two resonant high pass filters, two resonant low pass filters, two amplifiers, four ADSR envelopes and four LFOs. The oscillators features continuously variable wave shape and wide variety of modulation. The filters are modeled on the Sallen-Key filter circuit and cascaded OTA filter circuit for classic analog sound. The Effects include delay, chorus, flanger, reverb, eq and compressor. The sequencer features piano roll and parameter automation editor to program 16 bar pattern per clip. Project files can be saved in iCloud Drive, so that the project can be accessed from iPhone, iPad or Mac. - Main Features - Virtual analog polyphonic synthesizer. Maximum 8 voice polyphony. it depends on performance of the device it is running. Four oscillators per voice. Flexible audio signal and control signal routing. Keyboard Control Routing Two type of Lowpass filter, cascaded OTA model and Sallen-key model. Support MIDI 2.0 New User Interface built by SwiftUI for improved performance. Built-in Sequencer. 16 bar patterns per clip. Total 8 clips. Piano Roll and Parameter automation. Support Audio Unit Extension (AUv3) Works on iPhone, iPad and Mac. Support iCloud Drive to share project files between the platforms. Audio Export. Linear PCM format (AIFF, WAV and CAF) and compressed format (AAC) Support Ableton Link, Bluetooth MIDI, MIDI In / Out. 370 Factory Presets - System Requirements - A13 Fusion or above is recommended. AudioUnit Extension (AUv3) requires host application which support AudioUnit Extension. AudioUnit Extension is supported by Apple Logic and Apple Garage Band on iOS and macOS. For any other DAW, it depends on the application and some of them don’t support AudioUnit Extension. Sound may be distorted if CPU of the device doesn't have enough power. If it happens reduce number of voices.

Screenshots

GSDSP Quantum Filter3 screens
VAPolyQuad4 screens

Verdict

The call

The clearest difference is review sentiment: GSDSP Quantum Filter at 100% against VAPolyQuad's 0%. GSDSP Quantum Filter also leads on rating (5.0 vs 4.0) and update cadence (every 5 weeks vs every 22 months). On price, ratings volume, ads and in-app purchases there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

GSDSP Quantum Filter costs $14.99 and VAPolyQuad $14.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

GSDSP Quantum Filter holds the better App Store score, 5.0 against 4.0. Both are backed by a comparable volume of ratings — 3 and 5 respectively. Written reviews point the same way: 100% of GSDSP Quantum Filter's written reviews are positive against 0% of VAPolyQuad's.

UpkeepUpdate frequency

GSDSP Quantum Filter ships an update every 5 weeks, VAPolyQuad every 22 months. Both last shipped on September 22, 2026.

Scorecard4 real differences · 6 level
GSDSP Quantum Filter versus VAPolyQuad: the parameters behind the verdict, then further details
ParameterGSDSP Quantum FilterVAPolyQuad
Price$14.99$14.99
Rating5.0 (3 ratings) — better4.0 (5 ratings)
Positive reviews100.0% of reviews — better0.0% of reviews
Number of ratings35 — better
Update frequencyEvery 5 weeks — betterEvery 22 months
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPad, iPodiPhone, iPad, Mac
Requires iOS12.0 — better16.6
Further details — not scored
Size77 MB16 MB
Age rating4+4+
DeveloperGustav ScholdaRyo Togawa

Customer experience

GSDSP Quantum Filter

All ratings3 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews2 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

VAPolyQuad

All ratings5 ratings
Positive60.0%
Neutral20.0%
Negative20.0%
Written reviews1 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

In-app purchases

None

GSDSP Quantum Filter

No in-app purchases

None

VAPolyQuad

No in-app purchases

Questions

Is GSDSP Quantum Filter free?
GSDSP Quantum Filter costs $14.99, with no in-app purchases.
Is VAPolyQuad free?
VAPolyQuad costs $14.99, with no in-app purchases.
Which has better reviews, GSDSP Quantum Filter or VAPolyQuad?
GSDSP Quantum Filter is rated higher. GSDSP Quantum Filter averages 5.0 out of 5 from 3 ratings, while VAPolyQuad averages 4.0 from 5 ratings.
Do GSDSP Quantum Filter or VAPolyQuad have ads?
Neither GSDSP Quantum Filter nor VAPolyQuad shows ads.
Which is updated more often, GSDSP Quantum Filter or VAPolyQuad?
GSDSP Quantum Filter ships an update every 5 weeks, and VAPolyQuad every 22 months. Most recently, GSDSP Quantum Filter was updated on September 22, 2026 and VAPolyQuad on September 22, 2026.

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