Ahem... ?
Fret switching is an
old guitarsynth tech. The guitorgan from 1967:
Many other companies used fret switching, notably the Synthaxe (1986), used by Allan Holdsworth, Gary Moore (see the video for
Out in the Fields) which used fret switching as part of the MIDI sensing, some of the Casios. There was a new MIDI guitar controller posted recently (someone posted it here a few months ago), that was obviously fret switching too.
the Synthaxe:
The upside to fret switching is no tracking delay. The downsides are no velocity sensing, bending, vibrato or altered tunings and forget a low action, because any fret buzz on other frets causes the pitch to jump to the wrong notes.
For switchpads, look no further than the
Starr Labs Z-Tar:
Of course, guys have taken them to ridiculous extremes:
There's even a guy who plays drum solos on one!
The zero-crossing method of pitch detection is the most commonly used in guitar to MIDI conversion. There's always a delay between playing a note and the synth responding (because it has to wait for the transient attack to pass and the sustained note to sound for two wavelengths), which gets worse the lower the note (longer wavelength = more time to measure the zero crossing points). That's the method that's been used by Roland for years.
By far the best pitch-MIDI conversion is the "Neural Net" used in the (sadly now discontinued) Axon, which can recognise the note from the attack:
Quite ingenious, it measures the echo of the attack along the string to the fret and back to figure out the finger placement (and from the left hand to the bridge to figure out the picking position (do a patent search on Andras Szalay if you're interested in the full details). Works best for plectrum players, but double-checks itself (and senses bends and vibrato) with zero crossing, so at it's worst, it's as fast as a Roland.
Here's Guthrie Govan playing on an Axon/Graph Tech guitar for the first time at a NAMM show:EDIT: beaten to it...
