ABL3 vs Phoscyon 2 vs Acid V: which TB-303 plug-in should you buy?

They all squelch. Choose by how you write acid

Editorial Program sixteen steps, put a few accents on the off-beats, slide into the last note and push the resonance until it starts to complain. Whether that becomes acid comes down to three small behaviours: how the filter screams as resonance and envelope mod rise, how accents bite harder the closer together they bunch, and how slides smear one note into the next. Get those wrong and you have a resonant mono bass. Nothing wrong with that, but it isn't acid.

Editorial The other half of the instrument is the sequencer, and the way you write a pattern shapes the line as much as the cutoff knob does. That is where these three really split. Independent reviewers rated all three emulations highly, so the useful question isn't which one squelches. It is what kind of acid producer you are: the purist who wants the box, the finisher who wants the box plus a rack of distortion and effects, or the one who wants the box to start writing back.^{[1][2][3][4][5][6][7]}

The purist's 303: ABL3

Bass Line 3 (ABL3) lets you program it the old way. Its Classic view has pitch, Gate, Down, Up, Accent and Slide buttons like the original front panel, and in Note mode a velocity of 100 or more becomes an accent and overlapping notes become slides, just as when you drive the hardware from a DAW. Even the gate length defaults to a value chosen "to match the TB-303 as closely as possible".^[8][9]

It also reaches backwards in ways the other two don't. A wave analyser transcribes recordings of a real 303 into patterns, and it imports patterns from Roland's T-8 and TB-03, Behringer's TD-03 and ReBirth. Version 3.3.0 added an emulation engine that can model broken accents and slides. Beyond distortion and bass and treble controls, AudioRealism lists no effects and no modulators.^{[8][9][10][11]}

Editorial That short list is the point. ABL3 is for the producer who writes the line, rides cutoff and envelope mod by hand, and leaves distortion and delay to their own channel strip. If you already think in 16-step patterns, and especially if some of them live on a TB-03 or TD-03, a library that moves between box and DAW is worth more than any modulation matrix. As for an engine that can model a worn unit's broken accents: it is either the most authentic feature in this comparison or the most 303-obsessive. Probably both.

The sequencer isn't a perfect replica, though. Sound On Sound's Paul Nagle found it more fun than the original's, but in January 2017 he also noted that it omitted triplets and pattern chaining and didn't reproduce every trick of the original (Read Sound On Sound's ABL3 review ↗ (external site)). AudioRealism's current manual still describes no pattern chain, and it is marked "under construction", so expect to learn the 3.3 features from release notes.^[1][8]

It has records behind it. In a 2019 interview, Plaid said the main acid lines on "Los" were made with ABL3 (Read the Headphone Commute interview ↗ (external site)). Wehbba's 2024 breakdown of "Ticprei" credits it for the bassline, acid leads and stabs, although the bassline sequence itself came from a Max for Live patch and was edited before processing (Read the Magnetic Magazine breakdown ↗ (external site)). Neither source says which version was used.^[12][13]

The finisher's 303: Phoscyon 2

Editorial Phoscyon 2 is for the producer whose acid line isn't finished until it has been distorted, delayed, compressed and distorted again.

D16 keeps the original panel and adds seven knobs that it says come from popular hardware mods: slide time, sweep amount, envelope attack, accent decay, accent volume, and vibrato speed and depth. Behind those sits a calibration panel of nine trims named after the original's service pots. Then comes the chain: 19 distortion models with a compressor before or after them, and five insert effects (reverb, EQ, delay, chorus and limiter) that you can reorder.^[14][15]

Editorial Those mod knobs are where the musical value is. Slide time and accent decay decide whether a line glides lazily or snaps shut, and the fact that hardware owners modded them in tells you how much people wanted them. Nineteen distortion models is either generous or a dare. But if your acid parts always end up drenched in drive and delay anyway, you can print a finished part without leaving the plug-in.

It also has tools for performing a pattern rather than just storing one. Live Override forces accents, slides or vibrato during playback without changing the stored pattern, the arpeggiator plays a riff template built from the notes you hold, and the randomiser sets density separately for notes, octaves, slides, accents and vibrato. The voice has no LFO: vibrato is written as alternating notes, so slow sweeps come from your DAW.^[15][14]

Reviewers at MusicTech (Read MusicTech's Phoscyon 2 review ↗ (external site)), MusicRadar (Read MusicRadar's Phoscyon 2 review ↗ (external site)) and Gearnews (Read Gearnews's Phoscyon 2 review ↗ (external site)) all called its sequencer a clear improvement on the original's. Their complaints were about details. MusicTech's Adam Douglas would have liked to move the distortion, which sits at the start of the chain, and Gearnews's Dirk Behrens found no root-note setting for the randomiser and noted that the arpeggiator can't be randomised or exported.^[3][4][5]

In a July 2026 interview, BLONDEX named Phoscyon 2, or a hardware TD-3, as the source of the acid lines in an Ableton Live studio setup (Read the Music Connection interview ↗ (external site)).^[16]

The 303 that writes back: Acid V

Editorial The hardest job in acid techno isn't writing a good four-bar line. It is keeping that line interesting for eight minutes without drawing a forest of automation. Acid V is the one whose features line up with that problem. Set its accent lane to seven steps against a sixteen-step note lane and the accents walk through the pattern, landing somewhere new each bar. Add a little probability and the line keeps shifting without anyone redrawing it. Neither of the other two documents lane lengths like these.^[17][15][8]

In polymetric mode, its sequencer's note, octave, slide, accent and vibrato lanes each run at their own length. Per-lane dice set the chance of each step changing, custom scales carry per-note probabilities, and Transmutation regenerates a sequence in one click.^[17][18]

The voice goes past the 303 too: a sub-oscillator up to two octaves down, vibrato up to audio rate, three function generators that can be assigned to most parameters, and four effect slots in a fixed order. It is the only one of the three with a standalone version.^[18][17][19]

Both of its independent reviewers praised the sequencer, and both pointed out that its grid replaces the original's way of programming. Sound On Sound's Dave Cranmer liked it (Read Sound On Sound's Acid V review ↗ (external site)). MusicTech's Adam Douglas called it "deep, powerful and... intuitive" and singled out the modulation section as what sets Acid V apart from a typical acid box, but counted the departure from the original's programming and the fixed effect order as cons (Read MusicTech's Acid V review ↗ (external site)). Douglas reviewed Phoscyon 2 as well, and judged Acid V less tweakable in its modulation parameters but felt its extras made up for it.^[6][7]

Editorial That is the trade. Acid V is the least 303-like way to program a 303, and for evolving techno that is exactly why it wins. Put a slow function generator on cutoff and the sub under the line, and both the pattern and the sound move without a single automation lane.

Its sequencer travels beyond acid, too. In an undated Plugin Boutique interview, galen tipton describes routing its MIDI to other synths and drums to generate syncopated patterns that go well past conventional acid bass (Read the Plugin Boutique interview ↗ (external site)).^[20]

Which one sounds most like a real 303?

Editorial This is the argument forums never finish, and the published evidence is thinner than the arguments suggest. Every review cited here says its plug-in passes for a 303. Only one of them put a plug-in next to a hardware TB-303.

Acid V: Sound On Sound's Dave Cranmer compared it side by side with a hardware TB-303 and found them "very, very similar", with differences he put within the tolerances of early-1980s components (Read Sound On Sound's Acid V review ↗ (external site)). MusicTech's Adam Douglas called it "squelchy and meaty" and said the sub-oscillator restores bass lost at high resonance (Read MusicTech's Acid V review ↗ (external site)). Both reviews are from 2023.^[6][7]

Phoscyon 2: MusicRadar's Computer Music review said it "really does sound indistinguishable from an original 303" (Read MusicRadar's Phoscyon 2 review ↗ (external site)), and MusicTech's Adam Douglas called the sound "gorgeous" (Read MusicTech's Phoscyon 2 review ↗ (external site)). Gearnews's Dirk Behrens was convinced too, while noting that he owns only clones, not an original, and he heard D16's voicing as more aggressive than AudioRealism's (Read Gearnews's Phoscyon 2 review ↗ (external site)). All three reviews are from 2022.^[4][3][5]

ABL3: Sound On Sound's Paul Nagle called it "totally convincing" in January 2017 (Read Sound On Sound's ABL3 review ↗ (external site)), and Computer Music called its sound "fantastic" in April 2016 (Read MusicRadar's ABL3 review ↗ (external site)). Both reviews predate version 3.3.0, which changed the engine, so neither describes the ABL3 you would download today.^[1][2][10]

Editorial So there is no knockout on sound. Acid V has the only A/B against an original among these reviews, which counts for something, but one reviewer's ears are not a shoot-out, and the ABL3 reviews describe an engine that has since changed. If authenticity of sound is your whole buying criterion, run the demos on one of your own lines and trust your ears over anyone's adjectives.

Which one should you buy?

The small print

• Pro Tools: Phoscyon 2 and Acid V list AAX. ABL3 does not, and on Windows it comes as VST2 and VST3 only.
• Logic Pro: all three list Audio Units. Apple Silicon: all three list support, and Phoscyon 2 added AAX Arm64 in 2.1.0.
• Older systems: ABL3 lists macOS 10.13 and Windows 7; Phoscyon 2 lists Mac OS X 10.13 to macOS 26 and Windows 7, including 32-bit Windows hosts; Acid V needs macOS 11 or Windows 10, has the heaviest stated requirements (4 GB RAM, 3 GB disk, an OpenGL 2.0 GPU), activates through Arturia Software Center and doesn't support Windows on ARM.
• Linux: none of the three lists a Linux build.
• Standalone: only Acid V lists one. A release note mentions a stand-alone ABL3, but its product page doesn't list it.
• Microtuning: ABL3 and Acid V support MTS-ESP; Phoscyon 2's documentation doesn't mention it.
• Documentation: ABL3's manual predates the 3.3 features and doesn't explain the ABL3x name, and ABL3 has no pitch bend. Phoscyon 2's changelog is undated. Arturia's current pages don't say which VST version Acid V ships (the 2023 manual listed VST2 and VST3), the current Acid V manual wasn't available to us, and there are no public release notes for 1.1.x.^{[9][22][8][14][23][15][18][24][25][19]}

You may not need any of them

Editorial If you already own one of these, the core job is done: a convincing 303 voice with a step sequencer is common to all three, and MusicTech's Phoscyon 2 review made the same point about upgrading from a competing acid plug-in (Read MusicTech's Phoscyon 2 review ↗ (external site)). Owning all three is a collection, not a workflow. The same goes if you have a hardware 303 or clone whose sequencer you like; a plug-in mainly buys you recall and MIDI drag. And if you only want the occasional line, Midilab's JC303 is free, runs on Windows, macOS and Linux, and its maker lists a 16-step sequencer with accent, slide and tie plus some Devil Fish-inspired mods (See Midilab's JC303 page ↗ (external site)). It documents far less than any of the three here.^[3][26]

Editorial And if what you actually want is a squelchy resonant bass rather than 303 behaviour, a mono synth you already own with a low-pass filter and glide will get you a long way; these plug-ins earn their money on accent, slide and the sequencer. Still undecided? D16 and Arturia both offer demos, and AudioRealism says its plug-ins run as a trial with the audio fading periodically. It generally gives no refunds once a licence is registered, so try ABL3 first. Load each one on a line from a track you are actually making. If none of them makes you want to write another, keep the money: the cheapest 303 is the one you don't need.^{[14][18][9][21]}