Comparison

GSDSP Quantum Delay vs 501 Chorus Echo

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

Head to head
About

GSDSP Quantum Delay

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
Read full description

A vintage-inspired delay supercharged with deep modulation, flexible filtering, and creative timing that pushes echoes into new dimensions. Classic Delay, Reinvented Quantum Delay takes the charm of a vintage stereo delay and fuses it with our next-level modulation system. Switch between the warm character of Tape mode and the pristine clarity of Fade mode, lock to BPM (including 5-tuplets) or dial in precise times in milliseconds. Use the Fine control for subtle push-and-pull micro-timing — or modulate your delay lines in ways traditional delays could only dream of. Sculpted Echoes Shape your repeats with switchable lowpass, highpass, and bandpass filters placed directly in the feedback path. Add modulation to create evolving tones, gentle movement, or drifting, frequency-shifting echoes. From warm analog-style rolls to shimmering, swirling textures, it’s all there. Feedback with Precision Control your delay tail behavior using either traditional % feedback or our modern dB-per-second decay system — ideal for predictable, musical decay even when the feedback path becomes complex. Enable Crossfeed for classic ping-pong stereo bounce, or push into Over-Feedback to create dense, self-building echoes that drift toward infinity. Stereo or Dual Mono Every section of Quantum Delay — delay, filter, and feedback — can switch between stereo and dual mono modes. Create tight, controlled stereo images or break them apart for wide, offset, unpredictable spaces. Dual mono modulation unlocks complex stereo interplay and beautifully asymmetric echoes. Modulation Without Limits Quantum Delay integrates our advanced modulation system, letting you modulate nearly anything: delay time, filters, feedback parameters, stereo controls, and more. Use LFOs, Random Generators, 2D modulators, Envelope Followers, Macros, and even chaotic systems to push your echoes far beyond traditional delay behavior. Or use our parameter randomisation feature to explore the plugin’s sound at random. Quantum Delay 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

501 Chorus Echo

This audio plugin meticulously models the iconic Roland RE-501 Chorus Echo, offering authentic analog warmth with modern digital flexibility. It provides producers with classic tape delay, BBD chorus, and spring reverb sounds, enhanced by DAW tempo sync and expanded controls for any music genre.

Highlights
  • Authentic analog sound reproduction
  • Extended creative control with DAW sync
  • Intuitive user interface
  • Versatile for any music genre
  • Independent SOS timings
  • Linear preamp option
Features
Read full description

"Legendary Analog Warmth: Authentic Spring Reverb, Classic Tape Delay, and Lush BBD Chorus in a Cutting-Edge Plugin" Rediscover the iconic sound of the Roland RE-501 Chorus Echo*, now reborn as the NA 501 Chorus Echo plugin by Nembrini Audio. This meticulously modeled plugin captures the essence of the legendary tape echo, BBD chorus, and spring reverb, enhanced with modern digital functionality for today's music producers. Ideal for adding rich, analog textures to any genre, the NA 501 is a versatile tool for musicians and producers seeking that classic sound with contemporary flexibility. Key Features:: 1 - Authentic Sound Reproduction: Delivers the classic warmth and character of the Roland RE-501 through precise digital modeling. 2 - Extended Creative Control: Offers advanced features like DAW tempo sync, expanded chorus and delay parameters, and independent SOS timings. 3 - Intuitive User Interface: Designed for ease of use, blending vintage aesthetics with modern digital efficiency. 4 - Versatility for Any Genre: Whether you're producing rock, electronic, ambient, or beyond, the NA 501 fits seamlessly into any musical project. Equipped with features tailored for modern production, the NA 501 includes DAW tempo synchronization, a wide parameter range for the BBD chorus and analog tape delay, separate left and right SOS timings, and a linear preamp option. These technical enhancements ensure that the NA 501 not only emulates the classic sound but elevates it to new levels. Works as a standalone app, AudioUnit v3 effect, or Inter-App Audio effect Legal Disclaimer: RE-501 Chorus Echo is a registered trademark of Roland Inc. NA 501 Chorus Echo was developed by Nembrini Audio SRL based on its modeling techniques. Roland has not endorsed nor sponsored the NA 501 Chorus Echo in any manner, nor licensed any intellectual property for use in this product.

Screenshots

GSDSP Quantum Delay3 screens
501 Chorus Echo1 screens

Verdict

The call

The clearest difference is review sentiment: GSDSP Quantum Delay at 100% against 501 Chorus Echo's 0%. GSDSP Quantum Delay also leads on update cadence (every 5 weeks vs every 17 months) and rating (4.8 vs 4.5). 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 Delay costs $14.99 and 501 Chorus Echo $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 Delay holds the better App Store score, 4.8 against 4.5. Both are backed by a comparable volume of ratings — 17 and 8 respectively. Written reviews point the same way: 100% of GSDSP Quantum Delay's written reviews are positive against 0% of 501 Chorus Echo's.

UpkeepUpdate frequency

GSDSP Quantum Delay ships an update every 5 weeks, 501 Chorus Echo every 17 months. The most recent releases landed on October 9, 2026 and October 13, 2026 respectively.

Scorecard4 real differences · 6 level
GSDSP Quantum Delay versus 501 Chorus Echo: the parameters behind the verdict, then further details
ParameterGSDSP Quantum Delay501 Chorus Echo
Price$14.99$14.99
Rating4.8 (17 ratings) — better4.5 (8 ratings)
Positive reviews100.0% of reviews — better0.0% of reviews
Number of ratings17 — better8
Update frequencyEvery 5 weeks — betterEvery 17 months
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS12.0 — better15
Further details — not scored
Size94 MB23 MB
Age rating4+4+
DeveloperGustav ScholdaNembrini Audio

Customer experience

GSDSP Quantum Delay

All ratings17 ratings
Positive94.1%
Neutral0.0%
Negative5.9%
Written reviews4 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

501 Chorus Echo

All ratings8 ratings
Positive87.5%
Neutral0.0%
Negative12.5%
Written reviews1 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

In-app purchases

None

GSDSP Quantum Delay

No in-app purchases

None

501 Chorus Echo

No in-app purchases

Questions

Is GSDSP Quantum Delay free?
GSDSP Quantum Delay costs $14.99, with no in-app purchases.
Is 501 Chorus Echo free?
501 Chorus Echo costs $14.99, with no in-app purchases.
Which has better reviews, GSDSP Quantum Delay or 501 Chorus Echo?
GSDSP Quantum Delay is rated higher. GSDSP Quantum Delay averages 4.8 out of 5 from 17 ratings, while 501 Chorus Echo averages 4.5 from 8 ratings.
Do GSDSP Quantum Delay or 501 Chorus Echo have ads?
Neither GSDSP Quantum Delay nor 501 Chorus Echo shows ads.
Which is updated more often, GSDSP Quantum Delay or 501 Chorus Echo?
GSDSP Quantum Delay ships an update every 5 weeks, and 501 Chorus Echo every 17 months. Most recently, GSDSP Quantum Delay was updated on October 9, 2026 and 501 Chorus Echo on October 13, 2026.

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