Phaser set to stun, with up to 42 allpass filters in series delivering the deepest, richest phasing available. But is it an angel or a metal monster?
Bass frequencies can bypass the effect ('bass sanctuary') to ensure LF-stability. Feedback accentuates the comb filter effect, but unlike Uhbik-F the distance between peaks is kept fairly constant. As the signal is phase-shifted each time it is fed back, frequencies are created that were not present in the original signal – the main reason why Uhbik-P is also great for wild metallic effects!
Closely related to tape flanging is the classic phasing effect, which may originally have been an attempt to simulate tape flanging using electronic circuitry. While flanging is delay-based, phasing is achieved using a frequency-dependent phase shift. Either method results in a comb filter effect (multiple peaks/troughs) when mixed with the untreated signal, but there is a difference: In flanging, any modulation (e.g. from an LFO) changes the distance between the teeth of the comb, whereas in phasing this distance remains fairly constant.
Frequency-dependent phase shifts are the domain of allpass filters which, although they don’t affect the timbre of the audio material passing through them, will affect its phase. A rich, deep phasing effect requires several allpass filter stages arranged in series. The more stages a phaser has (Uhbik-P has up to 42), the more teeth in the comb. Two stages are required per tooth.
Most phasers have a feedback channel for added resonance, but something special is going on here: Because the signal is phase-shifted every time it is fed back through the filters, frequencies are created that were not present in the original signal. That’s why phasers can sound metallic.
The operation switch selects the number of allpass filters: 14, 28 or 42. Most phasers have fewer than 10, so even Uhbik-P’s lowest setting (14) can sound quite lush. 28 stages should be enough for a complex wash of sound, but Uhbik-P’s 42 setting makes it one of the richest-sounding phasers available. Note that the modulation effect appears deeper the more stages you use. To counteract this phenomenon, adjust modulation depth and LFO rate.
Spectrum and Depth
The spectrum parameter lets you move the comb around the frequency spectrum. Like cutoff in conventional filters, it defines the center position before any modulation. The Depth knob adjusts LFO modulation amount. Note that the actual modulation depth becomes less whenever the spectrum parameter is close to its lower or upper limit. Maximum depth therefore depends on the available headroom.
Adjusts the amount of feedback, either negative (phase inverted) or positive. It not only widens the cancellation areas (gaps between the teeth of the comb), but also creates more resonant peaks. As was the case with the flanger, high feedback values can lead to self-oscillation. For the sake of stability, Uhbik-P has been carefully calibrated so that self-oscillation is short-lived.
The mix knob controls the relative volumes of the dry and wet signals. The effect is most pronounced when mix is set to 50%. If higher feedback values are used however, you can remove the dry signal altogether i.e. set mix to 100%.
Like in Uhbik-F, bass sanctuary uses a highpass filter to eliminate bass resonance and/or unwanted panning effects: Bass frequencies remain effectively unprocessed.
Uhbik LFO parameters
Several of the plug-ins in the Uhbik collection are modulation effects which include a low frequency oscillator (LFO). They all have the same set of controls in the same positions:
Time Unit, Times
Modulation rate is controlled by a combination of the time unit and times parameters. The rate is continuously adjustable using the times knob, but depending on the selected time unit, it is either a time/frequency (in seconds or Hertz), a tempo (divisions of the current song tempo), or a manually set position within the LFO wave...
If quarters is selected, a times value of e.g. 16 means that the LFO wave has precisely the same length as 16 quarters. In this case, the higher the value of times, the slower the LFO. If 1/x is selected, 16 times means that the LFO cycle lasts for a 16th (semiquaver). In this case, the higher the value of times, the faster the LFO.
Similarly, if Seconds is selected, 16 times means 16 seconds. If Hertz is selected, it means 16 cycles per second. In general, the Quarters and Seconds modes are more suitable for slow modulation, whereas 1/x and Hertz are more suitable for fast modulation.
Manual lets you control modulation via e.g. parameter automation in your sequencer. In this mode, the LFO is effectively frozen unless you move the phase (see below) – which scans through the LFO wave manually or via automation. The times value here determines how many LFO cycles are included in the range of the phase knob. An example: times is set to 4. If you move the phase from 0 to maximum, you will have scanned through 4 complete LFO cycles.
Phase, Channel Offset
The LFO’s phase is particularly important in time unit modes that depend upon song tempo. The phase knob effectively shifts the LFO forwards or backwards in time – it adjusts the LFO phase so that modulation will rise and fall precisely where you want it to.
The channel offset parameter shifts LFO phase(s) between the channels of a stereo signal in opposite directions.
Wave, Scale, Symmetry
The wave parameter continually adjusts the basic LFO shape, from triangle to sine.
The scale parameter skews the wave vertically so that the upper half of the wave is shorter and more pronounced or longer and more subtle than the lower half.
The symmetry parameter skews the LFO wave horizontally so that the rising part is either shorter or longer than the falling part. For instance, minimum symmetry applied to a triangle wave makes it more sawtooth-like.
In combination, these parameters give you very fine control over the shape of the LFO. For instance, you can concentrate most of the effect on the “offbeat”.