Several people have asked me what a guitar tech does and how it is different than being a roadie. Well, the term "roadie" is considered a little demeaning in many circles since the actual job has become increasingly technical as new and better ways to put on a show put more demands on a tech than simply tuning a guitar. A guitar tech, at least the way I do it, is responsible for getting the artist's equipment ready to perform at it's best on a daily basis.
My typical day starts at 9:00 or 10:00 a.m., depending on what the particular venue is. Sometimes the lighting and audio crews need longer to get their gear loaded in and set up. When the lights and P.A. are far enough along to allow the space, the backline call comes. Backline is essentially all of the band gear: amplifiers, guitars, drum kits, keyboards, etc. All in their road cases, usually on wheels.
Once I get all of my gear in my "world", I open the guitar trunks amd remove all of the instruments and put them in "guitar racks", which are 6-space stands that the guitars rest in. I re-string every guitar every day, unless it does not get played more than one or two songs in the set. If the previous show was in an outdoor venue, I change all of them. If the artist has a corrosive sweat, you will certainly change every day. While changing strings, I check to make sure all of the parts of the guitar are functional. This would include examining the tuning pegs and nut, the volume and tone pots, the input jack, and the bridge and saddles. Any loose nuts or screws on the pickguard, neck or straplocks would be tightened. I check the intonation every few days. After stringing each guitar, I stretch the strings to get the play out of them so that after a medium tug, they return in tune. Any less and they will slip out under show conditions, any more and they get a bit dull. After all of that, I polish the guitar and put it back in the rack.
If the artist uses a wireless system, I change all of the batteries in each pack and check the RF level of every frequency. Sometimes you will get into cities and venues that have a lot of interference, so I find the audio guys and have them run a scan to find open freqs in the range of the wireless units I am using. I also check each pack and tighten screws and antennaes.
It's more common than not to have a pedalboard full of effects pedals. My responsibility is to keep them working and to make sure all of the knobs are on the right settings. Some artists have their guitar techs run ther effects for them, freeing them up to concentrate on putting on a better show. A popular controller that helps consolidate multiple settings is the Bradshaw switching system. It is fully programmable and can operate the various ins and outs of amps, pedals, rack gear and wireless units.
Amplifiers are also the guitar tech's gig. Keeping a tube amp up and running takes a little preventive maintenance. Spare tubes, a multimeter and a schematic will get you through most situations. Amp repair is not my forte, so I am glad that most artists I have worked for have plenty of spare amps on the road. In fact, spares are a necessity not a luxury. Any piece of gear that could cause a loss of more than a few minutes in downtime during a show should have a spare ready to go. This can nearly double the workload, but there is no option.
Any additional instruments will also fall under the guitar tech's job desciption. Harmonica, percussion, etc.
When showtime comes, I make sure all of the first two or three guitars are in tune. The trick is to stay at least one song ahead if you are working with an artist that changes guitars frequently during the show. They may decide to skip a song, and you need to be ready. Also, if you are running the pedalboard, you need to juggle tuning the next guitar while hitting buttons on and off, getting the next wireless system ready, and keeping a spare ready for whatever guitar is on stage at the moment. For example, let's say the artist is playing a Les Paul with P-90 pickups. After handing the guitar off on stage, I will come back to Guitar World and tune the backup, keeping an ear on the arrangement so I don't miss an effect or amp switching cue. I then begin tuning the next song's guitar, again hitting all of the cues, and after the song is over, I switch the effects and amp settings to the next song, switch the wireless unit and get the next guitar out to the artist.
This flurry of activity makes a set go by pretty quickly. As a tour progresses, you can fall into a groove and it all becomes second nature, which can be dangerous if you get sloppy. You need to keep focused at all times, and it is rare that you get a chance to actually enjoy the music like the audience does.