Comparison

AddStation vs OPL AUv3 FM Synth

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

Head to head
About

AddStation

Explore new sonic territories with this advanced additive synthesis tool. Create complex timbres by combining thousands of sine waves and unique morph sequencing. Integrate seamlessly with iOS production environments and enjoy a suite of built-in effects.

Highlights
  • Fractal additive synthesis
  • Sound morphing
  • Over 170 sound presets
  • AUv3 AudioUnit integration
  • Built-in effects suite
  • Audiobus 3 and Ableton Link support
Features
Read full description

The next generation of additive synthesis Additive synthesis is a sound synthesis technique that creates timbre by adding sine waves together. The timbre of musical instruments can be considered to consist of multiple harmonic or inharmonic partials or overtones. VirSyn already has a remarkable track record of products ( CUBE, POSEIDON ) trying to make this virtually unlimited synthesis method manageable for creative sound designers and musicians. AddStation is the next step forward giving you a tool to explore completely new sonic territory. The massive amount of sine waves in AddStation - thousands per voice - together with unique morph sequencing blocks blur the frontiers between analog and digital sonic realms. And all this integrated in all relevant iOS production environments especially the emerging AUv3 AudioUnit standard. Synthesis • Fractal additive synthesis • over 170 sound presets • Four parts with 8 Additive Sequence Blocks • Sound morphing • up to 512 partials per voice with independent AD envelopes • harmonic/inharmonic spectra • Ringmodulation • arbitrary filter function and noise spectra • four independent analog style Arpeggiators Effects • Chorus • Phaser • Flanger • Overdrive • Parametric EQ • Echo/Delay • Reverb Global • AUv3 for Host integration • Audiobus 3 compatible (Input slot) with state saving • Support for Ableton Link. • Inter-app audio compatible (Instrument/Generator) • CoreMIDI / Virtual MIDI • Audio recorder.

About

OPL AUv3 FM Synth

Emulates the iconic Yamaha OPL2 chip for classic game soundtracks and electronic music. Offers FM and additive synthesis with over 2000 presets and 16x oversampling for clear audio. Requires a MIDI keyboard for standalone use.

Highlights
  • OPL2 chip emulation
  • FM and additive synthesis
  • Distinctive percussion mode
  • 16x oversampling
  • Over 2000 presets
  • Standalone MIDI keyboard support
Features
Read full description

The Yamaha OPL chips, introduced in 1985, shaped the sound of 80s and 90s video game soundtracks. discoDSP OPL emulates their FM and additive synthesis, including the distinctive percussion mode, and extends it to four-operator FM on a pool of eight OPL3 chips. With up to 16x oversampling for crystal-clear sound and over 11,000 included instruments, discoDSP OPL is ideal for classic game soundtracks, electronic music, or crafting unique sounds. Play it with the built-in on-screen keyboard on iPad, a MIDI controller, or your DAW. On iPhone, connect a MIDI keyboard or run it as a plugin. CORE FEATURES • Eight-chip YMF262 (OPL3) voice pool with all eight waveforms per operator. • Up to four modulators and four carriers per note, with eight algorithms and a routing chart. • Percussion mode with bass drum, snare, tom, cymbal, and hi-hat. • Over 11,000 instruments: SBI categories, 4-op and OPL3 banks, game GM sets, and TX81Z voices. • Loads WOPL, WOPLX, OPLI, and TX81Z/DX sysex banks as well as SBI. • Oversampling from 1x to 16x, with a separate bounce setting. • Key-tracking stereo panning that places notes across the field by pitch. • AN1x-style unison with 32-step detune and stereo spread. • Master volume with Valve and Tape saturation. • MPE support with pressure and slide routable to synth parameters. • Sustain pedal and sample-accurate MIDI. • On-screen keyboard with pitch and modulation wheels (iPad, standalone). • Analog modeled wave shaper on the carrier. • SBI and SBIX instrument import and export through the Files app. • Bluetooth MIDI device discovery. • AUv3 plugin for GarageBand, AUM, Cubasis, BeatMaker, and Drambo. THE OPL SOUND Two-operator FM is the sound of Adlib and Sound Blaster era games. Each voice pairs a modulator and a carrier, each with its own waveform, frequency multiplier, envelope, and attenuation. Route them in FM for the metallic, bell-like timbres the chip is known for, or in additive to stack the two operators as independent tones. Feedback on the modulator pushes the tone from clean to gritty, and all eight OPL3 waveforms are available on every operator: sine, half sine, absolute sine, quarter sine, alternating sine, camel sine, square, and logarithmic sawtooth. They are the chip's own, not approximations. MULTI-OPERATOR MODE Add operators with the + and - buttons, up to four modulators and four carriers per note. Pick one of eight algorithms or draw your own on the Yamaha-style routing chart. Each patch is compiled onto the chip's 2-op and 4-op channels, and a pool of eight OPL3 chips keeps the polyphony up with larger patches and unison. PERCUSSION MODE The rhythm section repurposes the last channels into five dedicated drum voices: bass drum, snare, tom, cymbal, and hi-hat. It is how the chip made drums without samples, and it is included here in full. INSTRUMENTS Over 11,000 instruments are included. SBI sounds are sorted by category, the 4-OP and OPL3 folders hold four-operator game banks, Game GM collects General MIDI sets from classic PC games, and TX81Z holds Yamaha four-operator voices. Load one from the menu, step through them with the previous and next buttons, or import your own SBI, WOPL, WOPLX, OPLI, or TX81Z sysex files from the Files app. Anything you edit can be exported back out as SBI, or as SBIX for multi-operator patches. OVERSAMPLING The chip is emulated at up to 16 times the host sample rate, which stops the FM sidebands folding back into the audio band as aliasing. Playback and offline bounces have separate settings. ON-SCREEN KEYBOARD The standalone app on iPad includes a keyboard with pitch and modulation wheels, so you can play without any external hardware. The mod wheel drives a vibrato LFO with continuous depth, beyond the chip's fixed two-position vibrato. STANDALONE OR AUV3 Load OPL in any AUv3 host with settings saved in your project, or run it standalone with a MIDI controller, Bluetooth MIDI, or the on-screen keyboard.

Screenshots

AddStation4 screens
OPL AUv3 FM Synth1 screens

Verdict

The call

The clearest difference is update cadence: AddStation at weekly against OPL AUv3 FM Synth's every 3 weeks. AddStation also leads on review sentiment (82% vs 73%) and iOS requirement (12.0 vs 15.0). On price, rating, ratings volume 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

AddStation costs $9.99 and OPL AUv3 FM Synth $9.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

AddStation holds the better App Store score, 4.5 against 4.3. Both are backed by a comparable volume of ratings — 42 and 23 respectively. Written reviews point the same way: 82% of AddStation's written reviews are positive against 73% of OPL AUv3 FM Synth's.

UpkeepUpdate frequency

AddStation ships an update weekly, OPL AUv3 FM Synth every 3 weeks. The most recent releases landed on November 11, 2026 and November 3, 2026 respectively.

Scorecard3 real differences · 7 level
AddStation versus OPL AUv3 FM Synth: the parameters behind the verdict, then further details
ParameterAddStationOPL AUv3 FM Synth
Price$9.99$9.99
Rating4.5 (42 ratings) — better4.3 (23 ratings)
Positive reviews82.1% of reviews — better72.7% of reviews
Number of ratings42 — better23
Update frequencyWeekly — betterEvery 3 weeks
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS12.0 — better15.0
Further details — not scored
Size133 MB42 MB
Age rating4+4+
DeveloperHarry GohsDiscoDSP LLC

Customer experience

AddStation

All ratings43 ratings
Positive88.4%
Neutral4.7%
Negative7.0%
Written reviews39 reviews
Positive82.1%
Neutral2.6%
Negative15.4%

OPL AUv3 FM Synth

All ratings23 ratings
Positive87.0%
Neutral0.0%
Negative13.0%
Written reviews11 reviews
Positive72.7%
Neutral9.1%
Negative18.2%

In-app purchases

None

AddStation

No in-app purchases

None

OPL AUv3 FM Synth

No in-app purchases

Questions

Is AddStation free?
AddStation costs $9.99, with no in-app purchases.
Is OPL AUv3 FM Synth free?
OPL AUv3 FM Synth costs $9.99, with no in-app purchases.
Which has better reviews, AddStation or OPL AUv3 FM Synth?
AddStation is rated higher. AddStation averages 4.5 out of 5 from 42 ratings, while OPL AUv3 FM Synth averages 4.3 from 23 ratings.
Do AddStation or OPL AUv3 FM Synth have ads?
Neither AddStation nor OPL AUv3 FM Synth shows ads.
Which is updated more often, AddStation or OPL AUv3 FM Synth?
AddStation ships an update weekly, and OPL AUv3 FM Synth every 3 weeks. Most recently, AddStation was updated on November 11, 2026 and OPL AUv3 FM Synth on November 3, 2026.

Other comparisons