The Tronical Tune is a robotic system for guitar tuning which uses servomotor driven tuning pegs to actually tune the strings of the guitar, unlock DSP based "tuners" which do not actually tune the instrument but rather give you a digitally modeled sound that doesn't preserve the natural mechanical resonances of the instrument. The Tronical Tune is the same device marketed by Gibson on some of their guitars under the name "Min-E-Tune".
The device consists of a set of motorized tuners, a plate which contains the circuitry and control buttons and battery holder, and a rechargeable lithium ion batter. A charger is also supplied, as is all necessary mounting hardware and a small wrench.
There are a large number of different models which vary according to the spacing of the holes in the peghead of the guitar. Tronical has a downloadable pdf file of templates for the various guitar peghead styles to help you choose the correct version for your guitar. Other than the p0eghead style there is no difference in operation between the models. Each model is available in 3 different colors of peg.
Installation is easy. After reading the installation guide to know what not to do (overtightening certain parts could damage the servos), installation is pretty much like any other tuning peg change - it took me about 1/2 hour on my Epiphone '56 LP Goldtop reissue.
There is a bit of a learning curve with this device but it's not too bad. Leaning starts with string installation. YOU MUST READ THE MANUAL. The tuners use a locking device to hold the strings involving a threaded nut which should be tightened with a small coin, like a US penny (finally-a use for those) or dime. Do Not use a screwdriver or pliers, as overtightening might damage the motors. The string wraps around the post and is secured by the nut - there is no hole in the post. When the strings are installed for the procedure in the manual and it will tune the guitar for you.
The device holds 3 banks of 6 tunings each. Two or the banks are factory presets that cover all the common tuning variants and open tunings. The third bank is user programmable. Changing tunings is a matter of approximately three button presses and strumming and picking the strings. The Tronical senses string pitch via a piezoelectric sensor similar to those employed by the popular clip on tuners. The is no added pickup, alteration to the bridge or body, or anything like the clumsy system on the original Gibson Robot guitar.
Master tuning reference can be adjusted for those who use a pitch reference other than standard. There are adjustments for accuracy vs. speed of tuning and sensitivity to outside noise, as well as interference between strings. There is also a setting to compensate between the difference in acoustic or electric type string sets, as acoustics are usually heavier and use a wound G string. The device is rated for string gauges up to .013.
The device works as advertised. I got it so I wouldn't have to carry 3 different electric guitars for blues gigs - now I can use the same axe for standard and both open slide tunings. I've been using it with the stiffest rated string set - Ernie Ball "Not Even Slinkies" and it has given no problems.
Operation is fast but not instant - it takes a couple of minutes to tune, so it's slightly slower than DSP based systems - but it gives the real sound of the guitar, not a modeled tone derived from a piezo bridge pickup, and it preserves the natural resonances of the guitar which is crucial for playing in open tunings. I would not hesitate to recommend this to anyone with a need to use multiple tunings in the course of a set. It does what it's supposed to do, and is a useful tool, not a gimmick.
Once you get used to the procedure, changing strings takes about the same time as on a normal instrument.
Delivery from Germany was a bit slow (two weeks) but now they have US distribution.
If you're interested in this sort of device, download the manual and headstock templates from the website.
Note: I gave this device a "5" for sound quality although it actually makes no sound itself. However it allows the full sound of your instrument to come through, which DSP based schemes like the Autotune guitar and Variax do not.