Version OS 1.0
Because the F-OSC becomes an actual sine oscillator with increasing resonance, we call
the deviation of ideal resonance Dampen. Then the resonating filter oscillator decays in
form of an attenuated vibration if it's excited - similar to a single membrane that is hit.
In the MBrane there are two such F-OSC. With a strong Dampen the F-OSC really
becomes a continuously vibrating oscillator. The weaker the Dampen is, the more the F-
OSC becomes a filter with sharp q-factor (quality). This can be useful at e.g. snare
drums or HiHat-ish sounds.
Looking at the drumskins of an acoustic drum, there are 2 membranes positioned that
modulate and interact with each other by the coupling through pressure waves of the
content air. That produces the typical sound of a drum. By resonance and counteractive
interference of waves, new frequency bands and overtones are created.
The parameter Coupling works in a similar way in the MBrane. Both, in the first place
independently vibrating F-OSCs, can attenuate or gain the vibration of the partner by
means of coupling either way (1_2 and 2_1). With lightfingered tweaking you get these
interesting membrane-like dampened sounds, especially by cross-wise positive/negative
coupling. In order to obtain such a phase-wise cross coupling, the parameter 2_1
Coupling provides negative values too and has a phase flipping circuitry built in.
Furthermore, a slight frequency modulation is provided with every coupling parameter
(M1 M2 and M2 M1) that makes the cross modulation sound even more natural
→
→
and interesting.
In order to create snaredrum - or cowbell-like sounds, the MBrane has a noise
generator with its own envelope. A part of this signal is fed into the F-OSC network to
excite the "membrane" with the noise signal itself. Another part of the noise signal is
mixed into the final VCA (Voltage Controlled Amplifier) which produces the overall
volume envelope of the resulting instrument. The noise can be either white noise or
metallic noise, which is a binary pattern of different metallic sounding frequency bands.
In the Mod.Brane 11, there are two independent noise generators which can be mixed
together.
The length of noise decay and the decay of the resulting tone are controlled by two
different envelopes that are commonly controlled by the parameter Decay. The noise
envelope is always shorter than the final VCA envelopes. That lets you work out the
precise noise attacks by tweaking the Decay. The F-OSC's mostly have their own decay
themselves (changed by Dampen), and they only sometimes need their own (and then
longer) loudness envelope.
Two independent LFOs can modulate each of both F-OSCs or not. They always restart
with the note trigger and work like an additional pitch envelope.
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ALPHA BASE Operating Manual
