Comparison

iSEM Synthesizer vs Tera Pro

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

Head to head
About

iSEM Synthesizer

This app is a touch-based emulation of the classic 1974 Oberheim SEM synthesizer, known for its warm analog sounds. It offers a wide range of sonic possibilities, from fat basses to lively leads, and includes over 500 preset sounds.

Highlights
  • Classic Oberheim SEM emulation
  • Two oscillators with PWM
  • 12dB/oct multi-mode filter
  • Added LFO, Noise, Sub oscillator, Arpeggiator, Portamento
  • Polyphonic playability
  • 500+ preset sounds
  • MIDI and AudioUnit v3 support
Features
Read full description

COMPATIBILITY Apple’s AudioUnit v3, Inter-App Audio connectivity, AudioBus 3, Korg’s WIST and Apple’s CoreMIDI are all supported. Furthermore, iSEM is fully compatible with the Audio Unit Extension format. It can be directly launched in any Audio Unit host applications. DESCRIPTION iSEM is a recreation of the classic 1974 Oberheim SEM (Synthesizer Expander Module), one of the world's first self-contained synthesizer modules and the first to bear the "Oberheim Electronics" name. The Oberheim SEM was made famous by artists and bands such as Lyle Mays, Jan Hammer, Joseph Zawinul, Supertramp, 808 State, Vince Clarke and Depeche Mode. Based on the TAE® technology found in our Oberheim SEM V software, iSEM brings back the sound and special characteristics of this iconic synth in an sonically accurate and expanded touch-based emulation. What you can do with the iSEM? The iSEM is a powerful instrument capable of producing a wide range of warm analog sounds.  Reproducing the unique SEM architecture, with its oscillator sync, characteristic filter shape and specific envelope response, the iSEM is able to generate the fat basses that have made the Oberheim brand so popular. Thanks to its simple and clever PW and pitch modulations, it is also very easy to produce moving and lively leads. Its remarkable 12 dB/oct multimode filter is a real blast from the past, becoming an awesome weapon in the context of current electronic music. This unique module can instantly tailor your sound to fat, crisp, or spectral textures with access to all the nuances in between… iSEM comes with over 500 sounds that you can browse through and play. You can also easily create your own sounds with the easy to use interface. Play iSEM's numerous sounds from the iPad keyboard or control iSEM from a MIDI keyboard or other app via CoreMIDI and integrate it into your studio or live performance. If you are an owner of of the Arturia SEM V software on your Mac or PC, you can even import and export sounds between your laptop or desktop SEM V and iSEM. FEATURES All the original parameters of the Oberheim SEM: two oscillators, each offering sawtooth wave and variable-width pulse wave with PWM, sine wave LFO, 12dB/oct multi-mode Filter with low-pass, high-pass, band-pass and notch, two ADS envelope generators. Added functionalities: New LFO, Noise, Sub oscillator, Arpeggiator, Portamento. Polyphonic playability 8 Voice Programmer module allows each voice to have different settings HOLD and CHORD modes. Virtual Analog Chorus. Virtual Analog Delay. Full user MIDI mapping of panel controls. Supports WIST sync to other iOS devices. Support of AudioUnit Extension, AudioBus 3 and Apple’s Inter-App Audio connectivity. The Oberheim™ name used here is a trademark of the Gibson Guitar Corp. The trademark is used by license to Arturia.

About

Tera Pro

Explore a vast array of sound synthesis methods, from analog emulations to modern digital techniques. Combine modules for unique sonic textures, enhanced by an intelligent interface and realtime visual feedback. Expand your sound palette with additional modules available through in-app purchases.

Highlights
  • Multiple synthesis methods (analog, FM, spectral, additive)
  • Physical modeling and wave shaping
  • Intelligent user interface with realtime scopes
  • Flexible module routing
  • 128-voice polyphony with vintage voice modeling
  • Seamless sound switching
  • Extensive preset library
Features
Read full description

Tera Pro brings together all major sound synthesis methods on one table. No matter if you want to recreate sounds from analogue legends or explore modern digital sounds with FM, Waveshaping or Wavetable synthesis. More can be added by In-App Purchases of new modules. Add some flavour of physical modelling and modules for additive synthesis. Combine them altogether for new sound experiences far beyond your wildest dreams. Tame this overwhelming amount of possibilities with Tera Pros intelligent user interface showing you only exactly what you need, paired with realtime oscilloscopes and level indicators helping you seeing what’s going on. Connect the modules with a flexible routing method without the visual cluttering of real wire cables needed in conventional modular synthesisers FAQ What does Tera Pro have that Tera Synth doesn't have ? 1) Additional Sound Modules - Spectrum oscillator ( borrowed from the heart of Addictive Synth ) - Wave shaper / folder opens the west coast synthesis - Vocal Morphing filter - KARPLUS (aka WaveGuide ) with new "Swarm" mode ( 3 detuned delays ) 2) Revised engine - Analog Polysynth Voice Modelling with characteristic subtle voice variations of timbre, pitch and temporal behaviour to get you "The" Analog Sound. - 128 vs 32 voices polyphony - Seamless Sound Switching: change presets during play without cutting off the sound. - 8 times unison for really heavy ambients - Envelope generators with Buchla style "end of cycle" trigger for generative music - Stack/Split Sounds - New effect section 3) Redesigned User Interface - Collapsible modules for clear view of modular structure - No more nasty popups for LFOs/Envelope generators - Realtime oscilloscopes added to selected modules 4) New Presets - About 1000 additional presets in there. Tera never sounded this good... Tera Pro Specifications - 128 voice Modular polyphonic Synthesiser - Mono/Dual/Split Voice Architecture - Modules for analog and FM synthesis - Modules for Spectral Synthesis and Additive Synthesis - Karplus Strong Physical Modelling and Wave Shaping - MIDI Polyphonic Expression (MPE) - Vintage voice modelling for organic warm sound character - 1800+ Factory presets included - PDF Manual included - Standalone, AUv3 and IAA compatible - Ableton Link - Bluetooth MIDI - ... Additional modules through In-App Purchases: - Classic Wavetable synthesis with Import - Classic 6-OP FM Synthesis fully compatible to DX7 sysex files. - BrainZ multiple synthesis module based on MI Plaits Eurorack module. - RingZ physical modelling module based on MI Rings Eurorack module. - CloudZ granular synthesis module based on MI Clouds Eurorack module.

Screenshots

Tera Pro2 screens

Verdict

The call

The clearest difference is in-app purchases: iSEM Synthesizer at none against Tera Pro's 6. Tera Pro's advantage is rating (4.6 vs 4.1) and update cadence (every 5 days vs every 5 months). On review sentiment, ratings volume, ads and iOS requirement 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

iSEM Synthesizer costs $9.99 and Tera Pro $6.99 up front. Tera Pro sells 6 one-off in-app purchases. iSEM Synthesizer asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Tera Pro holds the better App Store score, 4.6 against 4.1. Both are backed by a comparable volume of ratings — 61 and 154 respectively. Written reviews complicate that: 74% of iSEM Synthesizer's written reviews are positive against 69% of Tera Pro's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

iSEM Synthesizer ships an update every 5 months, Tera Pro every 5 days. The most recent releases landed on October 15, 2026 and October 21, 2026 respectively.

Scorecard6 real differences · 4 level
iSEM Synthesizer versus Tera Pro: the parameters behind the verdict, then further details
ParameteriSEM SynthesizerTera Pro
Price$9.99$6.99 — better
Rating4.1 (61 ratings)4.6 (154 ratings) — better
Positive reviews73.7% of reviews — better69.4% of reviews
Number of ratings61154 — better
Update frequencyEvery 5 monthsEvery 5 days — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationPaidFree with in-app purchases — better
DevicesiPadiPhone, iPad, iPod — better
Requires iOS12.112.0 — better
Further details — not scored
Size80 MB306 MB
Age rating4+4+
DeveloperArturiaHarry Gohs

Customer experience

iSEM Synthesizer

All ratings60 ratings
Positive75.0%
Neutral8.3%
Negative16.7%
Written reviews243 reviews
Positive73.7%
Neutral9.1%
Negative17.3%

Tera Pro

All ratings155 ratings
Positive88.4%
Neutral5.8%
Negative5.8%
Written reviews72 reviews
Positive69.4%
Neutral18.1%
Negative12.5%

User reviews

iSEM Synthesizer

From 61 App Store ratings

What we love

  • 🎹 Fantastic sound quality
  • 💯 Faithful to the original Oberheim SEM
  • 🎨 Versatile sound design capabilities
  • 🎚️ Intuitive and responsive interface
  • 🔊 Rich, warm, and analog-like tones

Room to improve

  • 🐛 Frequent crashes and stability issues
  • 🔌 Poor integration with DAWs and MIDI controllers
  • 🕰️ Slow preset loading times
  • 🔇 Limited modulation options compared to hardware
  • 🤔 Uninspiring factory presets

Tera Pro

From 154 App Store ratings

What we love

  • 🎵 Exceptional sound quality and versatile synthesis capabilities
  • 💡 Innovative modular workflow with flexible architecture
  • 🎛️ Extensive preset library (1000+ presets)
  • 🔧 Powerful sound design tools with multiple synthesis types
  • 📱 Available on both iOS and macOS (M1)

Room to improve

  • 🎮 Steep learning curve and complex UI
  • ⌨️ Unconventional on-screen keyboard design
  • 🐛 Frequent crashes and stability issues
  • 🔊 Dangerously loud output without limiter
  • ⚙️ UI elements sometimes unresponsive or laggy

Bugs and requests

iSEM Synthesizer

Reported bugs

5 issues
  • Preset loading issues
  • MIDI connectivity problems
  • Unexpected crashes when switching between presets
  • Envelopes causing clicks and pops in some patches
  • Unresponsive controls when used as an AUv3

Requested features

5 requests
  • Add MIDI program change support
  • Improve preset management and organization
  • Implement a global tuning option
  • Enhance MIDI mapping and automation capabilities
  • Provide more comprehensive AUv3 support

Tera Pro

Reported bugs

17 issues
  • App crashes on macOS and iOS
  • Piano keyboard not appearing
  • Wavetable module IAP producing no sound
  • In-app purchases disappearing or not activating
  • Presets causing white noise or feedback blasts
Show 12 more
  • UI glitches preventing parameter adjustment
  • Randomize function not working with wavetable oscillators
  • Arpeggiator losing sync in AUM
  • No sound output until patch toggling
  • LFO panel crashes when adjusting settings
  • Wavetable oscillator remaining silent
  • MIDI Learn settings not clearable
  • App not appearing in iPad Settings or Files app
  • Patches with feedback that require MIDI Panic
  • Inconsistent oscillator routing display
  • Parameter adjustment randomly not working
  • Sample rate unable to be changed

Requested features

15 requests
  • Undo/Redo functionality
  • MIDI Panic button (prominent placement)
  • Output limiter for safety
  • Standard black and white keyboard option
  • Favorites/bookmarking system for presets
Show 10 more
  • MIDI Learn reset/clear functionality
  • Key Hold button on main screen
  • Sampler module
  • Many-to-many modulation matrix
  • Fully dark theme on all UI screens
  • MIDI Program Change support
  • Solo and Mute buttons for oscillators
  • Partial number indicators for spectral oscillator
  • Better file system integration for backups
  • Improved velocity/aftertouch separation on keyboard

In-app purchases

None

iSEM Synthesizer

No in-app purchases

6 purchases

Tera Pro

One-time6
  • Library WaveShaper$0.99
  • Module Waves$5.99
  • FM 7 module$5.99
Show 3 more
  • Module RingZ$5.99
  • Module BrainZ$6.99
  • Module CloudZ$9.99

Questions

Is iSEM Synthesizer free?
iSEM Synthesizer costs $9.99, with no in-app purchases.
Is Tera Pro free?
Tera Pro costs $6.99, and also offers in-app purchases.
Which has better reviews, iSEM Synthesizer or Tera Pro?
Tera Pro is rated higher. iSEM Synthesizer averages 4.1 out of 5 from 61 ratings, while Tera Pro averages 4.6 from 154 ratings.
Do iSEM Synthesizer or Tera Pro have ads?
Neither iSEM Synthesizer nor Tera Pro shows ads.
Which is updated more often, iSEM Synthesizer or Tera Pro?
iSEM Synthesizer ships an update every 5 months, and Tera Pro every 5 days. Most recently, iSEM Synthesizer was updated on October 15, 2026 and Tera Pro on October 21, 2026.

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