User Manual

SPECTRALIS 2

Hybrid engine - Oscillators, the improved LFO’s!

3.3.6 Oscillators, the improved LFO’s!

The frequency range of the LFO's is limited compared to real oscillators. As a

consolation we’d like to introduce you to something even better than LFO’s –

oscillators which can be tuned from subaudio all the way beyond the audible

range and can be used as modulators. This is why we’ve opted to refer to the

”Oscillators” as ”VCO”s (VCO stands for ”Very Cool Oscillator” in our case

;-)!). Similarities to terminology used in older analog synthesizer are purely

accidental and not intentional. OK, all kidding aside, in the filters you can use

up to four oscillators simultaneously as modulators for the filter-frequency.

Doing so allows for rather complex sound-changes and effects.

Please select song 5 of the Spectralis factory presets and select pattern 1. Playing

a key on your keyboard, you will now hear a pretty nice filter-self-oscillation-

effect with modulation, which should make you forget the missing LFO’s for

the moment.

As the oscillators also have pitch-envelopes the modulation speed can be

modulated as well. Let’s not forget that even FM- and PM- or time linearity

modulated waveforms can be the source of the filter modulation etc. Just a

little Bag of tricks for modulation freaks. Sooo - Let’s make a few changes to

the sound, to get an idea of the depth of the modulation possibilities.

First push the (CutOff LP)-encoder-button and select menu-page 8 of the filter-

menu with the help of the [Page-Up]-button. You will see the following display

message:

8/9:24dB Lowpass:exp. Filter FM

Osc1:0 Osc2:0 Osc3:0 Osc4:227

You can now see the menu for setting the exponential filter-frequency

modulation.The four parameters represent the modulation-depth of oscillators

1-4. If you are adding additional oscillators the various modulations will

superimpose each other resulting in more complex modulation waves. As this

cutoff frequency is controlled by the envelope as well, the cutoff-frequency

will be be increased with an overlaying modulation wave from the oscillators.

For the following experiments you can either hold down a key on your keyboard,

so the effect does not end early and you can make sound-changes audible

directly, or alternatively you can use the note-hold function of the Spectralis,

which the Spectralis’ MINI-keyboard has available. This second option works

as follows:

I. Push the [PLAY]-button in the parts section.

II. Use one of the numeric buttons [1]-[13] and hold down the selected

button down

III. While holding the selected button down, push the [Hold]-button

(numeric-button [15]).

IV. Even when you release both buttons now, the sound will still be

audible.

TIP: This hold-function can be a useful feature quite frequently when

editing the synthesizer. You must remember though, that you can turn off