A guitar player makes decisions. Decisions about gear, technique, composition, performance, attitude and lifestyle. These are all important, and they all contribute to making music. Gear is probably easiest to discuss, but it's not necessarily the most important subject.
I'm learning that versatility can't be bought. It's less a matter of gear-related features and more a matter of a good, responsive guitar and amp combined with technique that takes advantage of that responsiveness.
My journey over the last few years has led me toward increasing simplicity.
I've been through the modeling amp "one box wonder" phase. That lasted about a year before I realized that the amp was not only defining but also, in part, dictating my sound. Then I went to a channel switching tube amp and lots of effects. The effects were the first thing to go when I realized that I was spending way too much time worrying about effects and their place within a song. For a long time, I was happy with just a channel switching amp and a minimal palette of effects - an analog delay and (sometimes) a rotating speaker.
My first single-channel, non-master volume amp, more than anything else, helped to educate my ear about touch-sensitivity. I had always thought that channel switching was necessary to get a range of distortion ranging from clean to a lead sound. Now I've learned that using the amp's touch sensitivity to introduce distortion sounds better in the mix than switching channels to take a lead. There's still a place for channel-switching amps, because a single-channel amp has one voice and sometimes more variety is needed.
Everyone has their own path to follow, their own decisions to make. I'm going to tell you about my own gear decisions, and the experiences and the thinking that led me to them. Take it all with a grain of salt. Find your own way.
I like short (Gibson) scale guitars for their warmer sound, and the way chord tones blend. Longer (Fender) scale lengths give a brighter, twangy sound. (The compromise, in-between length popularized by Paul Reed Smith manages to miss the best attributes of either scale length, although some players recognize this as a desirable third choice.)
A double cutaway is essential for improved access to the higher frets. Despite the fact that I rarely play above the seventeenth fret, it's nice to have that extra room for my thumb thanks to the upper cutaway. Also, I prefer the aesthetics of a double-cutaway guitar.
Humbucking pickups are another must-have item. If you've ever tried to play in an electrically noisy room, you'll know what I mean. Aside from that, the sound of a humbucker is warmer than that of a single coil pickup, with fewer high harmonics. Humbuckers have a more even response to string vibration. (The humbucker senses string vibration at two nearby points, so frequency response variations due to nodal cancellations are reduced.)
Finally, I prefer a hardtail guitar. A tremolo tailpiece makes it harder for a guitar to stay in tune, and I'm really fussy about tuning.
After these essentials, the rest becomes a matter of taste and variety.
Despite my Gibson leanings, I love the sound of a Fender guitar mixed with a Gibson guitar. Toward that end, I have a Belgian-made Kritz guitar which is like a high-tech Strat.
The number of frets affects tone by determining the placement of the neck pickup. More frets make the neck longer, which moves the neck pickup closer to the bridge. The closer the pickup is to the bridge, the brighter its tone.
Humbucker equipped guitars commonly have either individual tone and volume controls for each pickup or a single tone and volume control affecting all pickups. The per-pickup controls give you the ability to blend both pickups for a wide range of tonal choices. Alternatively, you can preset the bridge and neck pickups for different tones and volumes, and select between them for different parts of a performance. Although a single tone and volume control configuration can help you concentrate on your performance, it does so at the expense of limiting tonal nuances.
Pickups affect both tone and distortion. Hotter pickups drive an amp harder, but tend to have a darker tone. There's no such thing as a good compromise. It really does make sense to have guitars with different pickups.
I string all of my guitars with a custom gauge set chosen to equalize tension across all strings in standard tuning. I use a wound third string because it sustains better and has more distinct overtones.
I prefer larger frets for a quicker playing feel and for ease of bending. The larger frets require a lighter touch on the neck.
I do my own setups. Action varies according to guitar. I try to compromise between fast action and easy bending. Proper intonation and tuning are very important. I use a strobe tuner both to adjust intontation and to tune the guitar.
I make a distinction between two major classes of amps: channel switchers and single channel, non-master volume amps. For a long time, I wouldn't consider anything but a channel-switcher, believing that their versatility is very important. Lately, though, I've discovered the unique joys of playing through a responsive single channel amp. A really good amp combined with the proper playing technique can sound great without any effects.
On the other hand, some music sounds better with less organic -- more synthetic -- guitar sounds. A channel switcher and a modest palette of effects can provide a lot of sonic variety. It's a different kind of expressiveness that depends more on the technology and less on the player.
Right now, I still find a need for both kinds of rigs. Will that change? Time will tell...
Channel switching amps
I use channel switching to vary the voice of my guitar as appropriate, setting the tone for an entire song or changing the feel as a jam progresses from one section to the next. For variation, I've learned to use the guitar's volume and tone controls. Blending the neck and bridge pickup in varying amounts, with different tone settings on each pickup, is a particularly powerful tool for shaping the sound of a guitar.
My channel switching amp is a Mesa/Boogie Mark IV. This amp traces its heritage to Fender designs, and has plenty of clean headroom with a smooth breakup at higher volumes. Although the amp has many controls, the fact that all three channels are voiced similarly makes it easy to set up. (The two lower-gain channels share bass and midrange controls, but have independent treble controls. This is less of a hindrance than you might think.) The four-bottle power stage accomodates different tube types and has switchable options for number of tubes in use and triode vs. pentode operation. The three-position power switch selects full or reduced operating voltages for yet another tonal option. The Mark IV sounds good at quiet practice levels, and even better once you push the output stage.
Single channel, non-master volume amps
My single channel, non-master volume amp is a Fender Custom Vibro-King. I have been told that the Vibro-King is basically a '59 Bassman married to a '63 Tube Reverb unit. Compared to the Bassman, the Vibro-King has a different input stage and some additional tone shaping, no cathode follower before the tone stack, no negative feedback, an LDR tremolo circuit, and a higher supply voltage with a solid-state rectifier.
The amp is very responsive to the guitar's volume and tone settings and the player's picking technique. The Vibro-King stay clean up to about 3 on the volume control (depending somewhat on the tone control settings). A little higher and you start getting into that responsive touch-sensitive area. Higher still and the full-on guitar sound develops a nice crunch, but you can still roll back the guitar's volume control to clean it up. Even higher, you start getting a beautiful lead sound that's sustained by the interaction between the amp and the guitar - controlled feedback becomes effortless, and you can still roll back the volume and lighten up your picking to clean up for a rhythm sound.
There are three benefits to playing like this. First, you have expressive control of distortion from note to note. Second, leads are naturally louder - you don't have to worry about balancing channel volumes. Third, there are no foot switches on the floor, which is a wonderful thing for me - I'm a terrible dancer.
Controlling the tone with my fingers took a while to learn. A single-channel amp on the edge of breakup can seem rather unforgiving to start. As with anything else, practice helps. Practice is a small price to pay, though, for the increase in expression that goes with the territory. There's one extra benefit, too. The simplicity of a single-channel amp means you can spend less time turning knobs and more time playing... or practicing.
I use a low-capacitance cable between the guitar and amp. This delivers the signal with a minimum of high frequency attenuation, and keeps the humbuckers from becoming muddy rather than warm. It's not a huge difference, just a matter of an additional bit of high-end sparkle.
I also have a Sennheiser digital wireless. This unit, unlike many guitar wireless systems, doesn't noticeably alter the frequency response or the dynamics of the guitar signal. Although the transmitter depletes its 9V battery at an alarming rate, an alkaline battery will last an entire evening and a NiMH recharechargeable battery will last for a full set.
To my ear, there's no effect more useful than a nice spring reverb. I use reverb all the time and set it to give just a bit of hangover from one note to the next.
The one effect I'll plug into the effects loop is an Electro-Harmonix Deluxe Memory Man; this can add some depth to single-note leads. This analog delay unit comes really close to the sound of a tape echo. (I won't use a real tape echo because of the maintenance headaches.)
A good compressor used with a touch-sensitive guitar amp can help to increase sustain at low to moderate volumes without noticeably sacrificing response to the player or the guitar's volume control.
I prefer open-backed speaker cabinets for my main sound. They seem to fill out a small room better, and can always be mic'd for a larger venue. I don't particularly worry about the reduced bass response of an open-backed cabinet; for the kind of music I play, the low end is covered by the bass guitar.
The late Philip Toshido Sudo has written eloquently about the philosophy of being a guitarist. I recommend his book, Zen Guitar.
Ralph Novack has written an informative article on the relationship between Scale Length and Tone.
Donald Tillman analyzes pickup response in his excellent article Response Effects of Guitar Pickup Position and Width.
Helmuth Lemme has written an informative article on the electrical characteristics of pickups. The English translation of The Secrets of Electric Guitar Pickups is provided courtesy of Martin Koch.