Anonymous user
Rob Hordijk OSC HRM: Difference between revisions
Jump to navigation
Jump to search
no edit summary
No edit summary |
No edit summary |
||
Line 110:
the velocity CV or CC# CV outputs of a MIDItoCV converter, but when modulated from
other sources one might need an extra CV mixer module to set the modulation levels properly
<br><br>
<b>Phaser Filter</b><br>
Price 325 euro<br>
The PhaserFilter module combines 5 allpass poles with three lowpass poles in one module.
The five allpass poles are configured as a phaser with positive feedback resonance control,
creating two resonant peaks when opened. Then a crossfade knob fades between the input and
the output of the phaser and this crossfade mix is the input signal into the lowpass filter. At
the end of the allpass chain before the crossfader is a phaser monitor output. The lowpass
section has a cutoff slope of -18dB/Oct and its own resonance control.
Both the phaser section and the lowpass section have a 1V/Oct control law. The phaser has
one modulation input and if it is not connected the audio input signal is used as the
modulation signal. This allows for dynamic waveshaping of the input signal on the time axis
without detuning to signal.
The filter section has two modulation inputs, if the first is not connected the filter audio input
signal is used to modulate the filter cutoff, allowing for even more dynamic waveshaping just
like in the phaser section. If the second modulation input is not used it uses a signal from
halfway the lowpass poles to selfmodulate, thus producing all-harmonic distortion on the
resonance peak when the resonance is set fairly high.
When the 1V/Oct input jack for the filter is not used it inherits the signal from the phaser
section 1V/Oct input jack.
Both phaser and filter can sweep over a range of roughly 18 octaves and can be modulated up
to really high audio rates. In this last case FM-type and ringmodulator-type effects occur, but
with much more timbral control than traditional ringmodulators. E.g. when the outputs of two
OSC HRM modules, set to sinewave output and tuned in some interval, are mixed and routed
into the filter just slight amounts of the internal modulation on either the phaser or the filter
will start to produce ‘undertones’ and ‘overtones’ that are sum and difference frequencies of
the interval. This exemplifies the idea behind the PhaserFilter architecture, to not only take
material away like a normal filter does but to also produce new material not present in the
input signal and combine the both to create a vast range of possible timbres
| |||