2XB303 Bass Sequencer EDM-303 4+

Electro Acid Synth Machine

Rob Wilmot

    • 4.8 • 30 Ratings
    • $3.99



A creative bass synth sequencer for creating electro melodies or dirty phat & funky pure acid techno 303 style basslines. With LIVE CONTROL feature to trigger and transpose both sequences and new synth pad layer.
Inspired by the acid house music scene. An IOS exclusive, compared to a modern equivalent to Rebirth (Rebirth was a popular tb - 303 clone a decade ago).
Look at the video tutorial for a how-to guide. Listen to what you can create easily with 2XB303.
Create electro, house, techno, edm or synth sequences using standard step functions as seen on various sequencers like the Roland SH 101 synthesizer. 
Built in pad layer than follows pitch. Transpose and trigger sequence even with MIDI
Your synth sequences can also be generated randomly, shuffled or modify just notes.
Easily capture whatever you hear and export to AudioShare, Audio-Copy, Email or iTunes Shared Folder.
Support for Audiobus 3 routing, Ableton Link, IAA (Inter App Audio)
Tweaking cut-off & decay Env-Mod & glide & accent etc for that classic sweet-spot acid growl Tap to dials to swipe up & down for fine adjustment of knobs.

The sound was first compared to a Cyclone TT - 303 synthesizer & tweaked to extend sound shaping beyond a just bass maker. Waves have optional harmonic version, noise, LFO, glide speed & PHAT/ BASS, and great effects. This is designed to give pure electro music creativity beyond an acid synth 303 bass maker to create dynamically fluctuating overlaying electronic patterns. A good addition to any electro, drum and bass, acid, techno, house and any other EDM fans

Use the keyboard for the following cool tricks:
[Sequence/Control/Transpose]: Transpose both channels simultaneously while playing. Now ability to trigger sequence too, with synth pad layer. (optional and 22 sounds)
[Sequence/Control/Pattern]: Instantly switch to a saved sequence while playing. Keys correspond to stored program numbers, starting from the current program thats loaded (key 1 is your current program, key 2 is current program+1). Highlighted keys show stored programs. This is great for building up live tracks, or instant crossfading between programs. You can also "Hold settings" so it locks settings like effects.

METRONOME: Toggle drum beats -better than tick-tocks to accompany your bass lines

LFO auto control low pass CUT-OFF and/or PITCH. The pitch level can give a vintage synthesiser effect subtly detuning with low SPEED or faster for chaotic random pitches.

EFFECTS (Global/master are in yellow.)
OVERDRIVE, COMPRESSION adjusts threshold, ratio, & gain. This is a global effect.
ECHO tempo synced with feedback & wetness.
SAVE ALL. When not playing, save to memory.

Ableton Link syncs with apps .Enable for precise timing without syncing. Press LINK button at the bottom for settings.
MIDI sync with External, Virtual or Audiobus. 2XB 303 can be master or slave. ( any simple class-compliant USB should work but some may need to be power assisted)
Virtual MIDI In is always on. If you send from another app AND receive MIDI clock then you will be receiving both MIDI CLOCKS. Choose only one unless you want double tempo (which can be interesting).
While Ableton Link is enabled you can send clock. This means you can use one app to control 2XB303 synth alongside external hardware sequencers
MIDI note data is sent out on each channel

Record a fixed length, default to 32 steps. Can be changed in settings.
Arming the sampling with CAPTURE (flashing). Starts at counter 1 (ON).
PLAY CAP to listen to your super cool sampled acid synthesiser loop.

Audiobus 3 and IAA (Inter App Audio) Support. Route audio to mix or record into other applications
Audio can be routed via IAA into apps like Apple's Garageband.
Garageband will also sync your sequence for excellent multi-track recording.

To save you press "Save all", it then flashes. Now choose destination ("!" means its occupied ) then press "Save All" to confirm.

What’s New

Version 3

It has been a while since this was updated so I hope you enjoy some of these updates and added features.
Updated Audiobus
Updated Ableton Link (includes remote start/stop)
Fixed audio level on channel 2 being louder
Balanced audio for drum sounds on metronome drum backing
Fixed Note On and Note Off from MIDI so this should hold note with a glide
Added Midi control of transpose using chosen channel. (Found in Settings/Midi)
Added Sequence Trigger from transposing with 2XB303 or MIDI (Found in Sequence/Control)
Added a new AutoPad sound layer that uses first note it finds in Channel 1 sequence to play a selected pad sound as backing track. (Found in Sequence/Control, On//Off and Sound 1-22). You can adjust volume in Mixer section. This can give some great results used with transpose in Control section.
Increase screen space for MIDI ports
Allowed editing of step while running. Just use counter -/+ buttons, in Edit mode and it freezes selected step to where you move to. Resumes following sequence by pressing Edit Menu again.
Add Info links etc like other apps - email link and video demo link
Auto initialise empty memory slot as it was confusing before keeping the older program loaded.

Ratings and Reviews

4.8 out of 5
30 Ratings

30 Ratings

Guycoolio ,

Really Nice 303

One of the best Roland 303 bass line synths I have heard on iOS. I like it better than Troublemaker and Bass Line. In its current state it is as authentic sounding as Syntronik’s 303 emulation, Rebirth 338 and Retronyms’ TT-303. It would be a go to app with AUv3 in my opinion. Works fine in AUM using IAA and syncs to tempo thanks to Abelton Link. Has decent effects (echo, distortion, and compression/ducking) that provide an old school vibe and a musically useful signal boost. Filter section is nice and it has midi capability. You can also capture the audio and send to AudioShare.

Sequencer is easy to use. The generate sequence feature is good and allows the user to pick the notes used. GUI is functional but further development for the entire app is welcomed. For the price, it is a no brainer to down load if you are a fan of this kind of sound. Honestly, you would have to purchase hardware in order to do better. Kudos to the developer.

Developer Response ,

Hi. Thank you for your great review. I hope also the recent updates have made it even better for you. I will be looking at UUv3 and if it is compatible soon. Recently 6X806 was released that works really well alongside this app. Feel free to send any suggestions to info@beatsnbobs.com
Thanks again!

anickt ,

Fun but... UPDATED

Still fun in 2022!

UPDATE: Dev very responsive. Has made some nice improvements. I give him another star! Check out his electronic drum/percussion app. Also very cool! I know the dev is working on updating this app. I brought up the knobs earlier but let me make it clear this is one funky app with lots of cool sounds coming out of it! PREVIOUS REVIEW: The knobs need work. They shouldn’t move as soon as you touch them. They also should have a little “friction”. They turn too easily. The best knobs in iOS let you tap on the knob and then move away from center to better see what you’re doing and to make finer movements. Since a lot of 303-ism is tweaking, this is the main area that needs to be addressed. I like it otherwise.

Developer Response ,

Thank you for updating the review for reflecting the latest updates.
Im super glad you are enjoying this.

NoUserErrorHere! ,

2XB303 4 Acid Victory

One may ask: do we really need another iOS 303 emulator? The answer (if you love 303s) is Yes and 2XB303 earns its place within the existing arena by offering some unique takes on the theme and sounding Great. I learned the (also awesome) 6X806 app first so it was easier to understand the workflow here and the recently improved knob control makes tweaking all the more fun. It’s also capable of less 303-ish sounds and (perhaps most importantly) I keep making new stuff with it. Yes!

Developer Response ,

Hi. Thanks for the review. I am very happy you are enjoying the 6X806 alongside 2XB303. This is much appreciated and makes it all worth it for me knowing people are getting some nice sound from them. By all means if you have any suggestions, send them over to info@beatsnbobs.com as Im always looking to improve them where I can. Thanks again!

App Privacy

The developer, Rob Wilmot, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

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