Creating PWM on the PX-5S
The PX-5S synthesis capabilities are still being explored. Its deep HexLayer architecture combined with its amazing filters have produced some stunning sounds, rivaling many dedicated synthesizers. Remarkable for an instrument that is first and foremost a “stage piano”.
At its heart, the PX-5S a sample based instrument. The waveforms it provides are digital recordings. While the range of waveforms is quite vast, they are “static” samples….meaning it is impossible to change a waveform’s shape over time the way an analog or virtual analog synthesizer can. Or at least it appears that way on the surface.
With the v1.10 firmware update, the PX-5S introduced several new capabilities. Included with this update the number of built-in waveforms was expanded, in particular a total of 6 new sawtooth waveforms. On the surface combining two different sawtooth waveforms allows the PX-5S to have a richer sound than using two identical waveforms. Two of those sawtooth waveforms however are not like the others, which can allow for some exciting new sounds.
Two of these are actually reverse or inverse sawtooth waveforms. When they’re heard one at a time, it would be nearly impossible to distinguish between the regular sawtooth and the inverted one. When you combine them, this is when the magic happens.
If the two waveforms are 100% identical, when they’re combined they actually cancel each out completely – you wouldn’t hear anything at all. As soon as you begin adjusting the pitch of one sawtooth vs the other the combination creates the PWM effect. This picture taken from Sound on Sound Magazine’s Synth Secrets article isn’t 100% accurate but essentially shows the result.
On the PX-5S itself, waveform #418 Sawtooth 2 and waveform #420 Sawtooth 4, are inverse waveforms. When combined with any of the other sawtooth waveforms in the PX-5S you can get a nice PWM effect simply by detuning one of the two. This can create some wonderful rich and thick sounding waveforms. You will however reach a point detuning the two waveforms from each other where it will sound less like a PWM effect and more like two waveforms that are simply far out of tune from each other. Luckily there is another method that can be utilized to achieve a PWM effect with a faster cycle.
To do this create a HexLayer tone with two identical sawtooth waveforms. On the Pitch page of one of the layers, scroll down and find the LFO Layer Depth. On one of the two layers,
set the LFO Layer depth to . Leave the other layer the default depth of 64. Next, leave Layer Edit and go to the LFO page and make adjustments as shown. You can adjust rate and depth to taste but now you have a faster PWM effect similar to what you’d find on a analog “string machine”.
These are only a couple of applications that can lead to some really remarkable PWM sounds.
Additional audio examples along with sounds to download for your PX-5S are coming.