Comparison

sumFX vs GSDSP Quantum Distortion

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

Head to head
About

sumFX

This app is a versatile audio effects processor for musicians. It offers a modular design with multiple high-quality FX modules and customizable slots, allowing for quick creation of unique sounds. Focus on your music with intuitive controls and visual feedback.

Highlights
  • Modular multi-FX processor
  • 8 high-quality FX modules
  • 8 FX slots with Wet/Dry control
  • 2 LFOs per slot
  • 50+ cross-platform presets
  • Pre/post waveform view
Features
Read full description

sumFX is a modular multi-FX processor for Mac/PC and iOS. Designed with simplicity in mind, to help keep you focused on the music and the sum of your efforts. Packed with 8 high quality FX modules and an available 8 slots, each loaded with Wet/Dry control, Global Wet/Dry, and 2 LFOs per slot, creating new unique sounds is quick and easy. 50+ cross-platform slot & chain presets are included to get you to any sound you need quickly and we’ve packed in an easy to use pre/post waveform view to help keep you focused on the result of your FX. Modules: -syncDynamics - Multimode dynamic FX with BPM sync attack/release (Noise Gate, Expander, Compressor, Limiter) -stereoFilter - Stereo filter with link or individual channel controls (LPF12, HPF12, BPF12, LPF24, HPF24, BPF24, Notch, & Formant options). -variMod - Multimode modulation FX with stereo offset (Chorus, Flanger,  Vibrato, Phaser, Tremolo,  & Auto Pan) -EQuator - Full high quality EQ module (3 Parametric Bands, High/Low Shelf, & HPF/LPF). -frostReverb - Multi-Mode (Original, Plate, Spring, Room) Stereo Reverb.  -bucketDelay - Stereo Analog Style Delay with individual channel control. -variPitch - Stereo Pitch Shifter with 3X Modes (Doubler, Harmonizer, & Full Control) -powerPhase - Multimode Saturation, Utility Gain In/Out, Mono Maker, Channel msDelay, & Phase inverter.

About

GSDSP Quantum Distortion

Explore four distinct distortion effects—Saturation, BitCrush, Ring Modulation, and Downsampling—blended and controlled via an intuitive XY pad. Shape harmonics, reduce digital resolution, introduce inharmonic motion, and create classic digital degradation for unique audio textures.

Highlights
  • Four distortion algorithms (Saturation, BitCrush, Ring Modulation, Downsampling)
  • Intuitive XY pad for blending effects
  • Custom waveshaping saturation
  • BitWarp for tonal variation
  • Tunable oscillator for ring modulation
  • Adjustable downsampling rate and jitter
  • AUv3 audio effect plugin
Features
Read full description

Four complementary distortion algorithms — Saturation, BitCrush, Ring Modulation, and Downsampling — blended and shaped through an intuitive XY pad. Saturation Shape harmonics using Quantum Distortion’s custom waveshaping saturation. Adjust Drive to set the intensity from subtle warmth to strong coloration, and use Asymmetry to introduce controlled even-harmonic emphasis of vintage tube characteristics. BitCrush Reduce digital resolution using BitCrush and reshape the crushed signal with BitWarp, which bends the quantization curve for additional tonal variation. This combination allows precise control over both the amount of reduction and the character of the resulting digital artifacts. Ring Modulation Introduce inharmonic motion using ring modulation, generated by multiplying the input with a tunable oscillator. Adjust frequency and amount in real time to create anything from light metallic shading to dense, shifting sidebands. Downsampling Lower the sample rate using Downsampling, reducing temporal resolution for classic digital degradation effects. Set the rate down to 200 Hz or introduce Jitter for controlled randomness, adding instability and movement to the downsampled signal. XY Pad Blending Navigate between the four distortion algorithms using the XY pad, allowing smooth transitions or static blends across the processing modes. The background updates to reflect the current region, providing clear visual feedback while exploring hybrid distortion shapes and interactions. Quantum Distortion 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

Screenshots

sumFX3 screens
GSDSP Quantum Distortion3 screens

Verdict

The call

The clearest difference is review sentiment: GSDSP Quantum Distortion at 100% against sumFX's 55%. GSDSP Quantum Distortion also leads on rating (5.0 vs 4.4) and update cadence (every 5 weeks vs every 6 months). sumFX's advantage is price ($9.99 vs $14.99). On ratings volume, ads, in-app purchases and monetization model 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

sumFX costs $9.99 and GSDSP Quantum Distortion $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 Distortion holds the better App Store score, 5.0 against 4.4. Both are backed by a comparable volume of ratings — 12 and 10 respectively. Written reviews point the same way: 55% of sumFX's written reviews are positive against 100% of GSDSP Quantum Distortion's.

UpkeepUpdate frequency

sumFX ships an update every 6 months, GSDSP Quantum Distortion every 5 weeks. The most recent releases landed on September 7, 2026 and September 22, 2026 respectively.

Scorecard4 real differences · 6 level
sumFX versus GSDSP Quantum Distortion: the parameters behind the verdict, then further details
ParametersumFXGSDSP Quantum Distortion
Price$9.99 — better$14.99
Rating4.4 (12 ratings)5.0 (10 ratings) — better
Positive reviews54.5% of reviews100.0% of reviews — better
Number of ratings12 — better10
Update frequencyEvery 6 monthsEvery 5 weeks — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS12.012.0
Further details — not scored
Size44 MB80 MB
Age rating4+4+
DeveloperOSC AudioGustav Scholda

Customer experience

sumFX

All ratings12 ratings
Positive83.3%
Neutral8.3%
Negative8.3%
Written reviews11 reviews
Positive54.5%
Neutral18.2%
Negative27.3%

GSDSP Quantum Distortion

All ratings10 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews3 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

sumFX

No in-app purchases

None

GSDSP Quantum Distortion

No in-app purchases

Questions

Is sumFX free?
sumFX costs $9.99, with no in-app purchases.
Is GSDSP Quantum Distortion free?
GSDSP Quantum Distortion costs $14.99, with no in-app purchases.
Which has better reviews, sumFX or GSDSP Quantum Distortion?
GSDSP Quantum Distortion is rated higher. sumFX averages 4.4 out of 5 from 12 ratings, while GSDSP Quantum Distortion averages 5.0 from 10 ratings.
Do sumFX or GSDSP Quantum Distortion have ads?
Neither sumFX nor GSDSP Quantum Distortion shows ads.
Which is updated more often, sumFX or GSDSP Quantum Distortion?
sumFX ships an update every 6 months, and GSDSP Quantum Distortion every 5 weeks. Most recently, sumFX was updated on September 7, 2026 and GSDSP Quantum Distortion on September 22, 2026.

Other comparisons