# isxynth vs GSDSP Quantum Delay

The clearest difference is rating: GSDSP Quantum Delay at 4.8 against isxynth's 3.7. GSDSP Quantum Delay also leads on update cadence (every 5 weeks vs every 34 months) and ratings volume (17 vs 3). isxynth's advantage is price ($7.99 vs $14.99). On review sentiment, ads, in-app purchases and monetization model there is nothing between them.

isxynth costs $7.99 and GSDSP Quantum Delay $14.99 up front. Neither carries in-app purchases, so what you see is what you pay.

GSDSP Quantum Delay holds the better App Store score, 4.8 against 3.7. That said, the two scores are not equally well evidenced: GSDSP Quantum Delay has 17 ratings behind it against 3, so its average is the more settled of the two. Written reviews split almost evenly too, at 100% and 100% positive.

isxynth ships an update every 34 months, GSDSP Quantum Delay every 5 weeks. The most recent releases landed on September 28, 2026 and September 22, 2026 respectively.

## The numbers

| Metric | isxynth | GSDSP Quantum Delay |
| --- | --- | --- |
| Price | **$7.99** | $14.99 |
| Rating | [3.7 (3 ratings)](https://appshunter.io/ios/app/isxynth/id6450951503/reviews) | **[4.8 (17 ratings)](https://appshunter.io/ios/app/gsdsp-quantum-delay/id6469328297/reviews)** |
| Number of ratings | 3 | **17** |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 34 months | **Every 5 weeks** |
| Monetization | Paid | Paid |
| Size | 8 MB | 94 MB |
| Requires iOS | **11.0** | 12.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Alexey Nadzharov](https://appshunter.io/developer/729549192) | [Gustav Scholda](https://appshunter.io/developer/1642323227) |

## What reviewers say

### isxynth

[App page](https://appshunter.io/ios/app/isxynth/id6450951503)

This music effect plugin allows spectral cross synthesis and morphing between two input signals. It separates noise and tone components, offering controls for blending, freezing, and time-based delays. Gestures on controls can be recorded and played back for dynamic sound shaping.

**Highlights:** Spectral cross synthesis, Morphing between two input signals, Noise and tone component blending, Freeze control for spectral blurring, 3-second delay lines per input, Gesture recording and playback

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### GSDSP Quantum Delay

[App page](https://appshunter.io/ios/app/gsdsp-quantum-delay/id6469328297)

This app offers a vintage-inspired stereo delay effect with advanced modulation, flexible filtering, and precise timing controls. It allows users to sculpt unique echo textures, from warm analog sounds to complex, evolving soundscapes.

**Highlights:** Vintage-inspired stereo delay, Deep modulation system, Flexible filtering (LPF, HPF, BPF), Precise timing controls (BPM, ms), Switchable stereo/dual mono modes, Advanced modulation sources (LFO, Random, Envelope)

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is isxynth free?

isxynth costs $7.99, with no in-app purchases.

### Is GSDSP Quantum Delay free?

GSDSP Quantum Delay costs $14.99, with no in-app purchases.

### Which has better reviews, isxynth or GSDSP Quantum Delay?

GSDSP Quantum Delay is rated higher. isxynth averages 3.7 out of 5 from 3 ratings, while GSDSP Quantum Delay averages 4.8 from 17 ratings.

### Do isxynth or GSDSP Quantum Delay have ads?

Neither isxynth nor GSDSP Quantum Delay shows ads.

### Which is updated more often, isxynth or GSDSP Quantum Delay?

isxynth ships an update every 34 months, and GSDSP Quantum Delay every 5 weeks. Most recently, isxynth was updated on September 28, 2026 and GSDSP Quantum Delay on September 22, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*