AudioProcessor for Synthesiser?

I have set up a Synthesiser class, along with a SamplerSound and SamplerVoice. Super simple. However, I'm wondering what is the easiest way to hook it into an AudioProcessorGraph? Do I have to implement my own AudioProcessor and pass the audio/midi data down to an internal synth object, or is there an easier way?

To me, it seems like the Synthesiser class should just be a subclass of AudioProcessor. Or maybe there could be a SynthesiserAudioProcessor class that just accepts a fully-configured Synthesiser in its constructor.

Yes, you have to implement your own AudioProcessor. See the Juce plugin demo for an example.