Ever since it first appeared in the ‘70s, flanging has been a popular effect, even defining the character of several famous recordings. The term “flanging” is often used instead of “phasing”, although there are significant differences between true flangers and true phasers...
The original flange effect was made during the mid ‘60s by mixing the output of two tape machines playing back the same recording (or recording the same material). Either tape could be slowed down slightly by applying pressure to the flange of the reel. When the “earlier” of the two tapes is then slowed down so that it becomes the “later”, this results in a dramatic effect called through zero flanging. In extreme cases i.e. using noise or other full-range signals, flanging sounds like the whoosh of a jet as it flies by. A good early example of flanging can be heard in the middle of the song Itchycoo Park by The Small Faces (1967). This type of flanging is seldom realized in software.
Of course a different method is used in guitarists’ stomp-box units: A short delay is fed back into itself and the delay time is modulated, creating an intense comb filter effect that becomes increasingly resonant as the feedback is turned up. Although this is less dramatic than through zero flanging, it does have the advantage of being almost equally effective on lower frequency material - even bass guitar! This type is closely related to the ever-popular chorus effect, the only differences being that chorus doesn’t have feedback and generally has a longer delay (typically 10 milliseconds and over). Most modern digital flangers, either as discrete hardware or computer software, apply the same principles.
Uhbik-F offers not only the delay+feedback method, but also through zero flanging - even both at the same time! It combines the advantages of the two techniques while keeping the user interface relatively simple. Note: Uhbik-F can also be used as a chorus effect.
Virtual Tape Machines
Uhbik-F simulates two tape machines (called A and B) per audio channel, with playback and recording heads that can even occupy the same position (impossible in the real world, of course). This means that feedback from tape A can be recorded to both tapes A and B while one of them is “catching up” with the other.
Uhbik applies the principle that only one tape machine needs to be slowed down for through zero effects - it is only necessary that both audio signals can somehow “meet at zero”. If both virtual tapes were slowed (as they usually are in real tape flanging), it would be impossible to maintain precise timing between tracks in a multitrack recording.
In Uhbik-F, tape machine B is slowed down and sped up via the LFO so that the delay between both machines, and therefore the comb filter effect, is smooth and continuous.
(LFO parameters are described in depth further down)
Depth and Delay
The central depth knob controls the amount of LFO applied to Tape B’s playback position - effectively how much the speed of Tape B is affected by the LFO. The range is 0 to 20 milliseconds.
The smaller delay knob applies a constant delay of up to 10 milliseconds. This is useful for chorus and flanging effects that use feedback (see below), but it diminishes the tape-flanging character.
Mix and Automix
The mix knob controls the relative volumes of the virtual tape machines. At 12 o’clock (‘Tape A’ position), the output is practically dry i.e. you should hear no effect. Moving the knob to the left or right mixes in tape B (the delayed signal) while fading out tape A (the dry signal). The two small dots mean 50% i.e. an equal mixture of both. If mix at either minimum or maximum, you will only hear tape B...
The negative half of the mix range inverts tape B, so the delayed signal is subtracted instead of added. Negative (A-B) values give you a more pronounced jet effect, but will cause total cancellation at -50% whenever the delay reaches zero: fix it in the automix...
The automix knob controls the amount of LFO modulating the mix. Use this to accentuate the bottom or top of the wave, or prevent total cancellation when mix is in the -50% position (A-B).
The Feedback parameter simulates the typical stomp box flangers - it allows negative as well as positive values. Note that extreme feedback can lead to self-oscillation, just like in the real thing.
bass sanctuary (low, mid or high) inserts a highpass filter between A and B so that bass frequencies can be kept under control – the position (stereo or quad) of bass frequencies remain stable while higher frequencies are being tossed around by the effect.
The drive knob adds second harmonic distortion to the signal resulting in a brighter, more pronounced effect. High values can introduce a significant amount of distortion, which can be useful for boosting the presence of ‘solo’ instruments.
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”.