Comparison

AUFX vs K7D

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

Head to head
About

AUFX

This app offers a versatile stereo delay audio effect with extensive customization options. It can produce a wide range of sounds, from clean digital delays to gritty dub echoes and flangers. The app supports processing external audio and other applications, with features for saving and sharing presets.

Highlights
  • High quality 32-bit DSP engine
  • Tape simulation (noise and warble)
  • Filters in the delay loop
  • Stereo delay, detune, and ping-pong
  • Dual LFO for modulation
  • Inter-App Audio and Audiobus support
  • Save, load, and share presets
Features
Read full description

A highly tweakable stereo delay audio effect, suitable for everything from clean digital delays to filthy dub echoes, flangers and broken cassette tapes. This app is part of the AUFX series, a collection of simple and powerful audio effect apps. • High quality 32-bit DSP engine. • A multitude of parameters to tweak to get a wide range of sounds. • Tape simulation (noise and warble). • Filters in the delay loop for typical dub sound. • Stereo delay, stereo detune, ping-pong delay. • Sinewave and random dual LFO for flangers and other modulations. • Process hardware input/output. • Process other apps through Inter-App Audio or Audiobus (input/filter/output slots supported). • Save, load and share user presets. • Supports Audiobus2 state saving • Comes with several bundled presets. • Fully MIDI controllable, including Virtual MIDI. • Background Audio. • Built-in lookahead limiter to prevent clipping. • Record the result directly in app. • Email recordings or export to AudioShare audio document manager app. • Access user presets and recordings through iTunes File Sharing.

About

K7D

This app offers a vintage tape delay effect with analog emulation and modern controls. It recreates classic hardware echo machines for a warm, characterful sound. Use it standalone or as an AUv3 plugin in iOS DAWs.

Highlights
  • Analog modeled dual playhead delay
  • Modeled microphone input with saturation
  • Normal and Ping Pong modes
  • High pass and Low pass feedback filters
  • Powerful LFO time modulation
  • BPM syncable delay time
  • MIDI delay time modulation
Features
Read full description

K7D is a powerful and affordable, vintage tape delay effect plugin for iOS. K7D recreates the hardware echo machines of the past using Imaginando’s signature style of obsessive analog emulation, but with an enhanced level of control from a sleek, modern interface. Using this approach allows a whole new world of creative possibilities, while still retaining a warm, full-bodied analog sound, bursting with character and personality. To give K7D it’s distinctive analog flavour, we studied and analysed the tiny details of what makes classic hardware delays great, and painstakingly recreated every subtle nuance for a fantastically authentic sound. Available as a standalone app and audio unit plugin, you can use it digital audio stations for iOS such as Garage Band, AUM, Cubasis, Auria, Audiobus, etc. Features - 1ms to 1 sec. dual playhead analog modeled delay with noise, tape distortion and mechanical vibration models - Modeled microphone input with pre-amp saturation - Normal and Ping Pong modes - Optimized gain staging and saturation algorithms for very musical results - Delay time spread between heads and stereo width control - High pass and Low pass filter on feedback path - Powerful LFO bipolar time modulation with multiple waveforms (sine, triangular, saw, square, sample and hold and filtered sample and hold) and possibility of inverted LFO phase on second play head (for added stereo imaging) - Delay time syncable with BPM - Possibility of delay time modulation via incoming midi notes - Oscilloscope visualisation of audio waveform and LFO waveform - Built-in patch manager - Audiounit compatible

Screenshots

AUFX4 screens
K7D2 screens

Verdict

The call

AUFX and K7D both sit at 4.6 stars, but that hides the real split: 90% of AUFX's written reviews are positive against 80% of K7D's. AUFX also leads on iOS requirement (9.0 vs 17.0). K7D's advantage is price ($3.99 vs $4.99). On rating, ratings volume, update cadence and ads 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

AUFX costs $4.99 and K7D $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.6 for AUFX against 4.6 for K7D. Both are backed by a comparable volume of ratings — 33 and 79 respectively. Written reviews are what separate them: 90% of AUFX's written reviews are positive against 80% of K7D's.

UpkeepUpdate frequency

AUFX ships an update every 2 months, K7D every 3 months. The most recent releases landed on October 21, 2026 and October 29, 2026 respectively.

Scorecard3 real differences · 7 level
AUFX versus K7D: the parameters behind the verdict, then further details
ParameterAUFXK7D
Price$4.99$3.99 — better
Rating4.6 (33 ratings)4.6 (79 ratings) — better
Positive reviews89.7% of reviews — better79.5% of reviews
Number of ratings3379 — better
Update frequencyEvery 2 months — betterEvery 3 months
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS9.0 — better17.0
Further details — not scored
Size6 MB113 MB
Age rating4+4+
DeveloperKymatica ABImaginando Lda

Customer experience

AUFX

All ratings33 ratings
Positive90.9%
Neutral0.0%
Negative9.1%
Written reviews68 reviews
Positive89.7%
Neutral1.5%
Negative8.8%

K7D

All ratings79 ratings
Positive87.3%
Neutral6.3%
Negative6.3%
Written reviews44 reviews
Positive79.5%
Neutral9.1%
Negative11.4%

User reviews

AUFX

From 33 App Store ratings

What we love

  • 👍 Great sound quality
  • 👍 High-quality plugins
  • 👍 Excellent effects
  • 👍 Impressive quality
  • 👍 Complete immersion

Room to improve

  • 🐛 Not AUv3 compliant
  • 🐛 Unusable in current incarnation
  • 🐛 Falling behind without AU3
  • 🐛 Lacking AU support
  • 🐛 Ironically lacks AU support

K7D

From 79 App Store ratings

What we love

  • 🎶 Incredible sound quality
  • 🎨 Creative and musical delay
  • 💡 Generous presets and easy to use
  • 💰 Top-tier for the price
  • 🕰️ Authentic tape delay feel

Room to improve

  • 💻 Extreme lag and crashes
  • 🐛 Audio delay issues and glitches
  • ⚠️ High resource usage
  • ❌ No background audio standalone
  • 📉 Randomiser not working (initially)

Bugs and requests

AUFX

Reported bugs

4 issues
  • Crashes when loading presets
  • Loading presets causes crash
  • Will NOT launch in AUM
  • Workarounds don't work

Requested features

10 requests
  • AUv3 support
  • Add creativity, functions, magic
  • AUv3 would solve the only problem
  • AUv3 compliance
  • Add AU3
Show 5 more
  • AUFX 5 release date
  • AU3 support needed
  • Morphing time function
  • Update ASAP
  • Fix preset loading crash

K7D

Reported bugs

8 issues
  • App crashing with many instruments
  • Project crashes and data loss
  • App not opening after crashes
  • App deleting progress
  • Randomiser not working
Show 3 more
  • App will not load
  • Digital pops and clicks with Audiobus 3
  • Dry signal only in one ear with stereo input

Requested features

9 requests
  • Fix background audio standalone
  • Fix randomiser feature
  • Improve CPU efficiency
  • Make iPad and iPhone versions compatible
  • Add reverse playback option
Show 4 more
  • Allow MIDI assignment for knobs/functions
  • Improve input selection for interfaces
  • Update for Audiobus 3 compatibility
  • Make UI elements larger and more visible

In-app purchases

None

AUFX

No in-app purchases

None

K7D

No in-app purchases

Questions

Is AUFX free?
AUFX costs $4.99, with no in-app purchases.
Is K7D free?
K7D costs $3.99, with no in-app purchases.
Which has better reviews, AUFX or K7D?
K7D is rated higher. AUFX averages 4.6 out of 5 from 33 ratings, while K7D averages 4.6 from 79 ratings.
Do AUFX or K7D have ads?
Neither AUFX nor K7D shows ads.
Which is updated more often, AUFX or K7D?
AUFX ships an update every 2 months, and K7D every 3 months. Most recently, AUFX was updated on October 21, 2026 and K7D on October 29, 2026.

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