ページを印刷する"vibrato": The highest position of the 3-way switch selects the vibrato effect. Now both the expression
•
pedal and the "vibrato" knob are usable. The knob controls the frequency of the vibrato, and the pedal
controls its strength, i.e. the pitch deviations from the base notes of the guitar strings. When the vibrato
knob is at the minimum position, the expression pedal instead controls the upward pitch bend up to a
maximum of a perfect fourth interval. In the other positions of the 3-way switch the "vibrato" knob has
no effect.
The effects can be stacked, except the vibrato that is only active when the 3-way switch is in that positio
The string pitch analysis has some limitations, because all the six string signals come stacked together in a
standard guitar pickup signal. The main limitation is that the software does not recognise the harmonics of a
lower base note as separate notes. The practical limitations are mainly relevant only with the octave interval,
and the octave + fourth (=3rd harmonic) -interval, i.e. a note blocks all its higher octave notes, as well as notes
above the octave + fourth pitch. In order to not unintentionally block higher harmonic notes, the player should
dampen those lower strings that are not played, and/or adjust the "threshold" knob more clockwise.
The frequency resolution vs. amplitude has limitations as well: the string detection software resolution goes
down to one seminote, but a strong neighboring note may obscure a weaker note +- one seminote apart.
Another limitation comes from the delay of the analysis. A few cycles are needed to find the frequency of each
note. The frequency resolution and latency are tied together: higher resolution inevitably means longer latency
and vice versa. Therefore we have tried to achieve a good tradeoff between an acceptable latency and good
enough note discrimination resolution. The limitations are described in more detail in a separate document
"PGV explained" in the website www.audiospektri.com.
The limitations of the string pitch analysis software
3