I am curious to know how an app for say a Moog can get it's specific sound quality inside the ipad. I always thought a particular synth's characteristic sound comes from the electronics inside the machine. How can Apple's computer electronics cater for all this wide range of sounds ? Just curious.

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Quote Marbury:

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I am curious to know how an app for say a Moog can get it's specific sound quality inside the ipad. I always thought a particular synth's characteristic sound comes from the electronics inside the machine. How can Apple's computer electronics cater for all this wide range of sounds ? Just curious.

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Apple's computer electronics just output the digital audio stream an app delivers to the audio driver. It doesn't make the sound.

The software models the synths characteristics through maths and digital signal processing and sends the resultant audio stream to the audio output, just like a CD player delivers an audio stream to it's audio output.

The iPad (& iPhone, iPod, etc etc) already has no difficulty in reproducing the authentic sound of all these synths already, does it? We hear them on endless songs from the 60s, 70s, etc on our 'retro' playlists in iTunes (and I do mean endless....)

So in a synth emulation like the wonderful Korg or Moog examples, the sound is generated by the app instead of on a recording, so all the iPad needs to do is faithfully reproduce the digital signals generated & modified within the app, which is emulating in the digital realm what the original analogue hardware was doing. Often the original waveforms are sampled from the original hardware oscillators and used as the sound sources for the apps, with modelled filters and envelope shapers added in-line to complete the synth model.

So all the tricky warm-retro-sounding stuff is done in the digital domain within the app, carefully modelled after the behaviour of the analogue original unit, so the iPad doesn't need to have any specific audio characteristics except to faithfully convert the digital output of the app into analogue audio for us to hear, nothing added, nothing taken away...

There's a SOS article here which sheds some light on the process of modelling vintage outboard; same principles apply.

Interesting. I always wondered why the. Apps are so small in memory compared to PC VST's. All we need are iPads with analogue valve converters.

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