3
Channel allocation method
The three alternatives how the separate string analysis results are output to the six
left and right side 3.5mm jacks are described in the following.
The
“picking order”
alternative allocates the notes starting from number 1 channel
in the timely order in which the guitar is picked. There is no pitch or amplitude
based ordering. If any of the string amplitudes decays under detection, the
corresponding channel is released to be used for any new note entering, otherwise the
channel remains unused. The main advantage of this method is that for any of the
channels, the amplitude and frequency will encounter no clicks as long as the same
note remains active. The disadvantage is that after a while, the order becomes
random in terms of any pitch order, therefore it may be difficult to determine a
sensible patch connection setup for any subsequent module in the rack. Another
disadvantage is that when a low pitch string is picked, the first note typically is
detected at one of its harmonic frequencies (although you do not hear it, because it is
rapidly damped), so the base note will be allocated to one of the higher numbered
channels and remains there.
As the
“pitch ascending”
alternative suggests, it keeps the output pitch values in an
ascending order, with the channel 1 for the lowest note, and packs the active channels
starting from no 1 without any unused channels in between. The advantage is
obvious when connecting the outputs to further processing modules. The order
remains deterministic. The disadvantage is that a new note that has pitch lower than
any of the present notes will then push all the higher notes to the subsequently
higher numbered output channels. However, the transitions are softened by suitable
interpolation, and this allocation method therefore is often the most practical when
considering patching the signals to other modules.
The
“skip zeros”
alternative is otherwise similar to the
“picking order”
method, but
it additionally removes any silent channels between active ones and packs the
remaining ones towards the lower numbered end of the six channels. The main
advantage is that typically, the maximum number of notes in guitar chords is four, so
a practical patch cable setup to other modules may easily leave the channels 5 and 6
unused. The disadvantage is that there are transition periods in case of the packing
operation is done, however, not in the case when a new note in any pitch is entered; it
will just be allocated to the lowest number available channel.
NOTE:
Regardless of the allocation method selected, the left and right side channels
keep their correspondence.
