Important Note: None of these filters are intended to have their frequency cutoff modulated by an envelope or another oscillator/LFO. Rapid frequency changes will introduce audio artefacts, clicks and popping noises. Some of these artefacts may be very loud.
Butterworth filters.
TD_Butterworth_HP
Type: Butterworth high pass filter.
Can be set from 2nd order filtering to 12th order filtering.
There is no internal clipping on the kHz input voltage, and the control voltage only has the 1V/kHz characteristic.
TD_Butterworth_LP
Type: Butterworth low pass filter.
Can be set from 2nd order filtering to 12th order filtering.
There is no internal clipping on the kHz input voltage, and the control voltage only has the 1V/kHz characteristic.
TD_P1Z1
Type: 1 Pole (6dB per octave), 1 Zero Filter.
A specific design of Butterworth filter.
Selectable filter modes: Low Pass, High Pass, Bandpass.
TD_P1Z1_ST
Type: Stereo version of the 1 Pole (6dB per octave), 1 Zero Filter.
A specific design of Butterworth filter.
Selectable filter modes: Low Pass, High Pass, Bandpass.
State Variable Filters.
TD_SV2
Type: Linear State Variable Filter
Note:- The kHz 0-10 V, and Res -10 – +10V inputs are not internally clipped so external voltage limiting should be applied to prevent illegal values being used.
Filter Modes; Low pass 12dB per octave, High pass 12dB per octave, Bandpass 6dB per octave, Band reject 6dB per octave, Low pass 6dB per octave,
High pass 6 dB per octave, All pass 12dB per octave.
TD_SV2_ST
Type: Stereo Linear State Variable Filter
Note:- The kHz 0-10 V, and Res -10 – +10V inputs are not internally clipped so external voltage limiting should be applied to prevent illegal values being used.
Filter Modes; Low pass 12dB per octave, High pass 12dB per octave, Bandpass 6dB per octave, Band reject 6dB per octave, Low pass 6dB per octave,
High pass 6 dB per octave, All pass 12dB per octave.
State Variable Formant filters.
TD_SVX4
Four zero peak gain state variable bandpass filters internally connected in parallel.
Notes: Primarily designed as a building block for designers to create their own formant filters. Having a quad filter module uses less CPU than individual filters.
Note:- The kHz 0-10 V, and Res -10 – +10V inputs are not internally clipped so external voltage limiting should be applied to prevent illegal values being used.
TD_SVX4_ST
Stereo version. Four zero peak gain state variable bandpass filters internally connected in parallel.
Notes: Primarily designed as a building block for designers to create their own formant filters. Having a quad filter module uses less CPU than individual filters.
Note:- The kHz 0-10 V, and Res -10 – +10V inputs are not internally clipped so external voltage limiting should be applied to prevent illegal values being used.
Audio Crossover Filters.
TD_Xover12
Type: 12dB per octave crossover filter.
Notes: The crossover frequency is not internally limited, so the crossover kHz input voltage should be clipped in case illegal values might occur.
This is module is built out of a standard State Variable filter and is suitable for modulation if need be.
TD_Xover12_ST
Stereo 12dB per octave crossover filter.
Notes: The crossover frequency is not internally limited, so the crossover kHz input voltage should be clipped in case illegal values might occur.
This is module is built out of a standard State Variable filter and is suitable for modulation if need be.
Hilbert 90 degree filter network.
TD_Hilbert_A
Type: Hilbert Filter network, this network creates 90 degrees phase difference between the two outputs.
Notes: This uses an IIR 2 x 8 pole 90 degree phase-difference network. The outputs are approximately 90 degrees apart in phase, which is needed to build frequency shifters. The approximation in phase shift is not a problem for frequency shifting in general because if the input frequency shifts, so does it’s ability to cancel out with the original signal.
TD_Slew2
Control signal “slewer”.
The type of slew can be set to; Constant rate, Constant time.
Notes on Constant Time: It takes the same amount of time to go from 0-1 or 0-10. 1 volt = 1 second. The curve is exponential.
Volts slew time is limited to a maximum of 20 seconds and a minimum of 1 millisecond.
Notes on Constant Rate: It takes less time to go from 0-1 than 0-10, as it moves at the same speed between points. 1volt per 1second. The curve is linear.
Volts slew rate is limited to a maximum of 20,000 volt per second and a minimum of 0.1 volt per second.
Useful for introducing “glide/portamento” effects for control voltages, removing “stepper” effects, and smoothing out the output of sample/hold generators.
TD_PeakHold
Type: Peak Hold Filter
Notes: Generally used as a Peak hold for GUIs, and is not recommended for audio use. (You need to use a DSP-GUI bridge or Patch Mem)
TD_PeakHold
Type: Stereo Peak Hold Filter
Notes: Generally used as a Peak hold for GUIs, and is not recommended for audio use. (You need to use a DSP-GUI bridge or Patch Mem)
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