iPad Screenshots


FM 304 is a set of Three 4 operator FM synths, each with integrated sequencers and onboard effects. FM 304 exposes all synth parameters with a one knob per function paradigm, allowing for quick, fun and intuitive real-time manipulation and creation of tunes and sounds.

Tech specs
— 3x four op FM synth
— 3x LFO
— 3x 16 step sequencer
— Effects: delay, reverb, chorus
— 100 save slots
— 8 algorithms
— Note frequency quantize

What’s New

Version 1.1.0

Audiobus 3 support
Inter-App Audio support
Background audio
Knob sensitivity adjusted for some parameters
Tempo calculation error fixed
Screen size scaling improvements

Ratings and Reviews

4.8 out of 5
4 Ratings

4 Ratings


❤️ it

Can have some fun little sessions with this one. Thanks for the update! Wish it had some multiout action and a tap tempo button and a pretty please for auv3 on all your groove box apps ;0
Also I love the app design on your apps very well done quite beautiful thanks!

Oceans in space ,

Mind blowing fm beats

Very unique, and 4 fm drum synths in a window with all parameters! I feel the need to be minimal as is the app, yet the results are very intense and insane fm capacity overflowing the wires in the mind of the iPads soul. Seriously great idea to just put all the knobs and sliders on one page to ease the overwhelm.

rcon303 ,

fm sequencing madness!

sounds great and alot of fun!i wish the knobs were bigger its hard to adjust on ipad mini .

App Privacy

The developer, DesignByPaul, has not provided details about its privacy practices and handling of data to Apple. For more information, see the developer's privacy policy.

No Details Provided

The developer will be required to provide privacy details when they submit their next app update.


Paul Betowski
25.2 MB

Requires iOS 10.0 or later. Compatible with iPad.



Age Rating


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

More By This Developer

You May Also Like