Comparison

HeadStack vs 055U4RY

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

Head to head
About

HeadStack

This app offers a virtual tape loop with 8 independently configurable playback heads for creating diverse echo effects. It captures the warmth of classic tape machines while offering modern flexibility for sound design, from vintage echoes to evolving ambient textures.

Highlights
  • Multi-head tape engine with 8 playback heads
  • Vintage tape character and imperfections
  • Independent control for each playback head
  • Rotating head wheel for dynamic effects
  • Granular harmony engine for pitch-shifted textures
  • Per-head modulation and creative feedback routing
  • Diffusion and smearing for atmospheric washes
Features
Read full description

HeadStack is a multi-head tape delay inspired by the character, movement and musicality of classic magnetic echo machines, reimagined for modern production. At its heart is a virtual tape loop with 8 independently configurable playback heads. Each head can be positioned, levelled and panned to create everything from vintage slap-back echoes and rhythmic repeats to vast stereo soundscapes and evolving ambient textures. While HeadStack captures the warmth and unpredictability of classic tape systems, it is not limited by their mechanical constraints. Individual heads can be modulated, filtered, diffused, pitch-shifted and transformed into granular playback engines, opening up a palette that ranges from authentic analogue echoes to shimmering harmonies and cinematic atmospheres. The tape itself becomes an instrument. Rotate the head wheel to continuously reposition playback points, stretch the spacing between heads, introduce head loss, or create cascading feedback networks that evolve with every repeat. Independent filtering, stereo placement and modulation allow each head to develop its own character within the delay line. You can even play sequences Into HeadStack and freeze it using your hold pedal and continue to play over the top. Whether you’re searching for vintage tape ambience, rhythmic multi-tap delays, lush granular harmonies or experimental feedback textures, HeadStack combines the soul of a classic tape echo with the flexibility of a modern creative effects processor. Welcome to a new generation of tape delay. HeadStack Features: Multi-Head Tape Engine - Create complex rhythmic delays using multiple independently controllable playback heads running on a shared virtual tape loop. Vintage Character - Capture the warmth, movement and musical imperfections of classic tape echo machines with adjustable tape loss, filtering and feedback behavior. Independent Head Control - Each playback head features its own level, pan, timing offset and tonal shaping, allowing intricate delay patterns and evolving stereo textures. Rotating Head Wheel- Continuously reposition or stretch the virtual head arrangement to create shifting rhythms, moving echoes and dynamic performance effects. Granular Harmony Engine - Transform individual heads into pitch-shifted granular voices, generating harmonies, octave layers and shimmering textures directly from the tape loop. Per-Head Modulation - Add movement and expression with independent modulation of playback position, spacing, tremolo and stereo placement. Creative Feedback Routing - Choose between traditional multi-head feedback or route feedback from a specific playback head for unique echo patterns and evolving repeats. Diffusion & Smearing - Blend between precise rhythmic echoes and spacious, atmospheric washes using integrated diffusion processing. Deep Stereo Imaging - Create anything from focused mono echoes to wide immersive soundscapes with per-head panning, Haas delay and stereo enhancement controls. Performance Ready - Designed for real-time interaction, encouraging hands-on manipulation of head positions, modulation and feedback while performing. Precision & Experimentation - Dial in authentic tape echoes, lush ambient delays or push the engine into unpredictable granular and feedback-driven territories. Modern Workflow - Combines the immediacy of classic hardware with the flexibility, recall and precision expected from a contemporary audio plugin. Interactive Head Wheel - Grab and rotate the virtual head wheel to reposition playback heads, create evolving delay patterns and perform dramatic tape-style scrubbing effects. Dynamic Tape Warping- Enable Rotate and Stretch modes to continuously morph the spacing and timing between playback heads, transforming static echoes into living, breathing rhythmic textures. Freeze Buffer - Freeze the contents of the audio buffer using a foot pedal, capture ideas and play over the top.

About

055U4RY

This app is a unique polyphonic synthesizer designed to evoke horror-themed soundscapes. It features a distinctive visual interface resembling a haunted DOS terminal with a skull motif, offering a variety of synthesis engines and effects for creating unsettling audio.

Highlights
  • 8-voice polyphonic synthesizer
  • 15 synthesis engines
  • Twin chaotic LFOs
  • Shepard-Risset layer
  • State-variable filter
  • Sample-rate reducer and bit-depth crusher
  • Real-time stutter buffer (GLTCH)
Features
Read full description

055U4RY (say it: "ossuary") is an 8-voice polyphonic synthesizer sealed inside a haunted DOS terminal — and, since 1.30, a second plug-in that turns the same machine loose on any audio you feed it. A photographic ASCII skull is the front panel: its jaw hinges open with the amplitude envelope, its eye sockets ignite with the output level, and the whole interface tears, melts and reassembles itself while you play. THE VOICE - 15 synthesis engines: detuned saw/square/triangle unison stacks, sine and sub-oscillators one and two octaves down, two-operator FM, ring modulation and inharmonic partials. Every factory preset is a different engine. - Twin chaotic LFOs that cross-modulate each other's RATE, so pitch and filter drift never repeats. Held notes stay alive and slightly wrong. - A Shepard-Risset layer tuned beneath every note: five windowed partials in an endless downward glissando - the bottomless-pit illusion of classic horror scoring, fused into the oscillator core. - A 19 Hz infrasonic tremolo at the edge of perception. On headphones it is a shiver; on a big system it is pressure. THE CHAIN - State-variable filter, low-pass or band-pass per engine, with resonance that will scream - Sample-rate reducer and bit-depth crusher for terminal-grade lo-fi - Saturating drive stage - GLTCH: a real-time stutter buffer that seizes and re-loops your signal - CRYPT: a damped, pitch-black comb/allpass reverb - GLIDE: exponential portamento up to 1.5 seconds - DOOM: one macro that leans the chaos, the descent and the tremor deeper into the signal PERFORM - 14 knobs, all ASCII, every one audible on every preset - 15 factory presets with per-preset patch memory: your tweaks persist for each preset, and [RESET] restores the factory sound - Two-octave on-screen keyboard with octave transpose and note names - Hardware MIDI in (all sources auto-connect), built-in Bluetooth MIDI pairing, pitch bend, MIDI 2.0 aware - The skull is your meter: jaw = envelope, eyes = level, decay = how hard you push GLTCH 055U4RY FX - THE EFFECT The same app installs a second, separate plug-in. Put it on a drum loop, a guitar, a vocal or a whole mix and run it through the machine: - The full destruction chain as an insert - drive, bit crusher, sample-rate reducer, stutter, filter and the CRYPT reverb - in true stereo - HAUNT: a cross-fed delay whose repeats rot as they decay, with MURK controlling how fast they turn to mud - SYNC: stutters and echoes locked to your host's tempo, 1/16 through 1/1, or free-running - DOOM as an injector: the endless Risset descent and the 19 Hz tremor printed underneath your audio, so anything you feed it gains a bottomless falling drone that was never in the source - Fifteen presets sharing the instrument's names, each a different topology - Wet/dry MIX, output trim, and a skull that reacts to whatever passes through AUv3 + STANDALONE The synth runs standalone with zero setup. Both plug-ins install into your host: AUM, Logic Pro, GarageBand, apeMatrix, WBTRK and any AUv3-compatible DAW, with full parameter automation - "hejluxom: 055U4RY" under instruments, "hejluxom: 055U4RY FX" under effects. One purchase, every platform: iPhone, iPad and Mac. No accounts, no ads, no data collected - your patches never leave the device.

Screenshots

HeadStack4 screens
055U4RY3 screens

Verdict

The call

The clearest difference is price: 055U4RY at $6.99 against HeadStack's $12.99. HeadStack's advantage is iOS requirement (14 vs 17.0). On rating, review sentiment, ratings volume and update cadence 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

HeadStack costs $12.99 and 055U4RY $6.99 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 — 4.8 for HeadStack against 4.9 for 055U4RY. Both are backed by a comparable volume of ratings — 5 and 13 respectively. Written reviews split almost evenly too, at 100% and 100% positive.

UpkeepUpdate frequency

HeadStack ships an update every 9 days, 055U4RY every 5 days. The most recent releases landed on October 12, 2026 and October 14, 2026 respectively.

Scorecard2 real differences · 8 level
HeadStack versus 055U4RY: the parameters behind the verdict, then further details
ParameterHeadStack055U4RY
Price$12.99$6.99 — better
Rating4.8 (5 ratings)4.9 (13 ratings) — better
Positive reviews100.0% of reviews100.0% of reviews
Number of ratings513 — better
Update frequencyEvery 9 daysEvery 5 days — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPad, iPodiPhone, iPad, Mac
Requires iOS14 — better17.0
Further details — not scored
Size25 MB2 MB
Age rating4+9+
Developer4Pockets.comLASZLO DOBROVOLSZKI

Customer experience

HeadStack

All ratings5 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews4 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

055U4RY

All ratings13 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews8 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

HeadStack

No in-app purchases

None

055U4RY

No in-app purchases

Questions

Is HeadStack free?
HeadStack costs $12.99, with no in-app purchases.
Is 055U4RY free?
055U4RY costs $6.99, with no in-app purchases.
Which has better reviews, HeadStack or 055U4RY?
055U4RY is rated higher. HeadStack averages 4.8 out of 5 from 5 ratings, while 055U4RY averages 4.9 from 13 ratings.
Do HeadStack or 055U4RY have ads?
Neither HeadStack nor 055U4RY shows ads.
Which is updated more often, HeadStack or 055U4RY?
HeadStack ships an update every 9 days, and 055U4RY every 5 days. Most recently, HeadStack was updated on October 12, 2026 and 055U4RY on October 14, 2026.

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