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6. Building a classic wavetable synth voice

1 Fathom CM’s ability to generate and combine wavetables is very powerful, but as mentioned earlier, wavetables only spring to life when modulated. This modulation-driven scanning – and a classic analogue signal path – earned the PPG Wave its legendary status. We start where we left off in our previous tutorial, but return the Frequency knob to 1.0.

4 Now, we click Signal Flow, choose our Wave Table component (the only one yet in play) and then go back to our parameters editor. With the Amount knob set to 0, we click its centre to make it a modulation target, Add Mod, then choose another ADSR as the modulator. Set the modulation amount to around 0.70.

2 Next, we set our operator wavetable’s Index back to its first position. That’s the rightmost Index knob. Our sound is quite abrupt, so click the Oscillator button on the left to get to our familiar Oscillator controls. We reduce the Volume to 0, and click its centre to select it as a modulation target, then Add Mod, choosing an ADSR as its source.

5 The composite wavetable now shifts from our operand to our operator in a very dramatic fashion – it’s a bit too dramatic, to be honest! Let’s add another segment to our envelope and draw a more interesting shape. Once again, we increase the Period, this time to over 11. When we play and hold a note, we get a slowly shifting timbre.

3 We crank the amount of modulation to full, then adjust the envelope to create a less static overall amplitude. We decrease the attack level on ours, and increased the release time. We also give the Period knob a little nudge to expand the whole thing. Our sound now rings out a bit for a bell-like tone.

6 We’ve now got a lovely chiming timbre with some real interest in the sustain segment of the sound. Let’s add another element of interest by assigning a Note Velocity modulator to affect the amount of our most recent envelope modulator.