Roxsyn Guitar Synthesizer for iOS

Yonac Software has introduced Roxsyn, a new iOS guitar synth that turns your guitar or bass into a polyphonic synth.

Here’s what they have to say about it:

Unhappy with cold and temperamental guitar-to-MIDI synths that dominate the market, we developed a completely new approach to guitar synthesis. Our all-original technology synthesizes your guitar directly, without the use of MIDI notes. Rescued from being a poor keyboard substitute, your guitar suddenly becomes an integral part of the synth. It’s alive!

There is no pitch tracking involved. There are no pitch estimation errors, octave glitches, or garbled chords. There is no over-complicated G2M between your guitar and synth to destroy everything human about your playing. Instead, Roxsyn’s metamorphic sound generation technology retains all the personality of your sound: vibrato, slides, bends, dynamics, even extended technique. The result is a polyphonic synthesizer that is as fast and accurate as it is richly expressive.

No need for special MIDI pickups or hardware, either: just plug into your favorite Lightning/USB audio interface, and start synthing!


  • Synth Engine – Roxsyn’s heart is its three metamorphic signal generators (AKA oscillators). Each generator offers 5 unique waveforms, and has a 4+ octave range. They also feature stereo panning, and can route into either of Roxsyn’s dual filter banks.
  • Dual Filter Banks – Each containing four custom virtual-analog filter types and dedicated envelopes, the filter banks help sculpt the synth generators in countless new ways. The envelopes are specially designed for the guitar, and are driven by a fully adjustable automatic trigger generator controlled by your playing dynamics. Envelopes offer original features like finite-duration sustain stages, as well as the ability to receive or ignore trigger-off messages. They can also be triggered externally via MIDI controllers like an expression pedal. An additional envelope controls the amplitude of the signal, giving you even more options in creating synth sounds.
  • Arpeggiator – There are 8 stepping algorithms to choose from, as well as settable note value, swing, and note repeats. You can even route the arp to any combination of the 3 voice generators — enabling you to layer a non-arpeggiated sound with an arp pattern. What’s more, the arp can send trigger signals into any of Roxsyn’s 4 envelopes, and even reset the LFOs. So it’s also a handy rhythmic / trance tool as well!
  • Modulation & FX – Roxsyn’s modulation matrix lets you manipulate parameters (pitch, amplitude, filters, etc) using its two LFOs and mod envelope. Add subtle vibrato, even glide simulation, or go full-on berserk. LFOs each have 9 waveforms, and feature beat syncing. Each matrix row can take LFOs or the mod envelope as a modulator or control, and can even use external control sources.
  • Effects – Roxsyn comes with stereo FX: Algorithmic reverb with the sound of countless rooms, phasing, modulating, 2-channel delay, and graphic EQ.
  • Other Features: – 500+ factory presets with bass, lead, pad, arp sounds & more. Easily create & share your own presets. Audio Unit v3, IAA, Audiobus, Ableton Link. 64-bit processing at up to 96kHz. 160+ MIDI controllable parameters; MIDI learn & map save/share. Tapedeck (in the app), so you can record, loop & share your ideas on the go.

Roxsyn is available now for US $9.99.

14 thoughts on “Roxsyn Guitar Synthesizer for iOS

    1. Any iOS compatible audio interface.

      From the post:

      No need for special MIDI pickups or hardware, either: just plug into your favorite Lightning/USB audio interface, and start synthing!

  1. “No pitch tracking involved”. Ummm, don’t understand how it works how does it follow the notes you’re playing?

    1. It really is perplexing. Supposedly it is directly synthesizing based on the waveform of the input. But I don’t understand it. It may be some clever way of using spectrum (lots of narrow-bands) to sync oscillators, but that’s a total guess.

  2. Warning subjective, off the cuff first impression:

    I hear three paraphonic oscillators that track up to three of the notes I last played. The presets all tend toward distortion. As with all these guitar interfaces, I find it better to just play a keyboard for keyboard parts.

    1. playing with both the presets and creating from scratch, you can get some ambient and other sounds, you just need to tweak it. when you open an init patch it sounds like distortion but if you just change the osc shape it doesn’t any more

  3. I guess it is directly waveshaping the audio input into the desired waveforms. Or resetting sawtooth by zero crossing audio input and then rescale volume, just like certain old DCO hardware did it. You can derive other
    shapes from sawtooth then.

    There has been a recent guitar synthesizer released by Boss based on this technology. Could have given the inspiration.

  4. The demos have been pretty impressive. I bought it. Will tinker with it tomorrow.

    I even heard drums going through it and it was crazy cool.

    Whatever they did is really something. I don’t use this phrase often, but “game changer”.

    I expect it will be immediate in terms of response, but there’ll be the latency inherent iOS (and even desktop) based rigs.

  5. It’s a nice app. I think it will be very useful for effecting tracks in a mix setting.

    One gripe has more to do with iOS music apps generally, which is that the latency is significant enough to make it MUCH LESS useable in a live/realtime setting. It’s a shame, because it clearly is tracking in a very effective way, but the inherent latency of getting audio in/out of iOS apps is a joy-killer.

    My second gripe is just that the noise generator in the app seems “always on”– it does follow the envelope/trigger, but doesn’t gate down all the way when you don’t play. So between notes, there’s a continuous flow of noise. It might be addressable in the mod matrix, using the target “Noise Volume”. Will need to mess with that more.

  6. tengo un iphone con jailbreak y descargué la aplicación para probarla.., no soy tecnico ni mucho menos.. solo un curioso.., he logrado obtener buenos sonidos pero no puedo eliminar ciertos armonicos indeseables.., seguiré investigando.., si logro resultados talves la adquiera..

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