Pitch shifting uses delay with the clock on the output shifted up or down to change the frequency of the
notes you're playing.
A frequency shifter is basically one half of a ring modulator. !
While a ring modulator takes an input signal and a modulation signal and produces the sum and difference
frequencies, a frequency shifter produces only the sum frequencies, or the different frequencies. It outputs
these separate frequencies and invoques fancy filtering.
When you turn up controls, you can get glissandos, barberpole flanging, or soft echos that seem to rotate
around you.
Some refer to this effect as a ring-modulator, but it is not true. Its Bode Frequency shifter with Hilbert
transformation effect (rotate copy of signal to 90 degrees). Frequency shifters can sound like bells because
they shift inharmonics, which sounds exactly like ring modulation. In technical language it is known as single-
sideband modulation.
It is arguably one of the most underrated and ignored effects in the industry.
If you blend a slightly shifted signal with the original signal you can get some phasing. The harmonic
structure of the dry signal with the processed signal can sound as an inharmonic effect, much like a bell.
Freq shifters shifts up all frequency content up by the same amount, thus altering the frequency
relationships. As example, the 100 Hz tone go up to 200 Hz, and the 200Hz tone go up to 300 Hz instead.
HARMBODE frequency shifter can shift all of the frequencies of the input signal with up, down, up/down,
and down/up modes. These modes create dissonance to the incoming signal, breaking harmonic structure.
With frequency shifters it is possible to touch on other aspects of Phaser effects.
With variations of small and big shifts, it can break the harmonics of many instruments, but with many
percussion style sounds, a frequency shifter can change the tone and the effect can be very musical.
Small shifts gave deep phasing effects, larger shifts with notes changes is break harmonic structure and
create dissonance. Intresting to know the history - originally freq shifters was help to reduce mic feedbacks
in halls.
The effect uses a Hilbert Transform, that contains 2 seperate channels - Real and Imaginary. Real and Imag
are summed after the Frequency Shifter block where they are mixed with the dry signal.
Note: Ring modulation is equivalent to double-sideband suppressed-carrier modulation, whereas a
frequency shifter is equivalent to single-sideband modulation.
