Roxsyn is "the world's first metamorphic guitar synthesizer" for the iPad. The app lets you connect to your guitar and when you play it comes from the synthesizer sound. It also offers a complete package of knobs to refine and shape the resulting sounds, just like a regular keyboard driven synth.
But – and this is important – it's not just using your guitar as a MIDI controller for a normal synthesizer. Let's have a look.
Roxsyn guitar synthesizer app
Usually, a guitar-controlled synthesizer takes the guitar's sound, detects pitch (and maybe other parameters), and converts it to MIDI signals. The advantage is that MIDI can control virtually all electronic musical instruments, plus all music folders. The downside is that the first tracking can be undesirable and you may lose a lot of the expression contained in the guitar.
Roxsyn, from developer Yonac, uses neither MIDI nor pitch tracking. Instead, it uses an undiscovered method to connect the guitar signal directly to the synthesizer. My guess is that it somehow uses the actual guitar signal as a bass sound, so a regular synth generates its own bass signal using a low frequency oscillator. It's a pure guess on my part.
No matter how it gets there, the results are impressive. Roxsyn manages to work with polyphony (chords) as well as with individual notes. It feeds this into a variety of filters and can shape the signal using different square, tooth and other waves.
Just like a real synth
If you are familiar with subtractive synthesis, this seems to work the same way, just with a guitar in front. You can refine and sculpt your sound, all without giving up the amazing expressiveness of the electric guitar. And the filters and other effects are set to work best with a guitar (although you can input audio from other sources).
Arp and FX
On top of this is an arpeggiator, which is a tool for playing a sequence of notes based on a single input note. Or it can split the notes into a chord and play them at a time, in different patterns. You can program these patterns or use the supplied ones.
Roxsyn also provides several effects commonly used with guitar – reverb, stereo delay, chorus / flanger, phaser and EQ. Take a closer look in the Roxsyn manual (.pdf).
All in all, this seems like a fantastic tool for guitarists. You can even use it with a guitar simulation app on your iPad.
Price: $ 9.99
Download: Roxsyn from the App Store (iOS)