Guide to getting and playing better gigs
Buying An Amp
Buying new:
The first thing to decide on is how much power you really need. For a guitar, 15 watts is ideal for practice or home recording, but if you want to gig then you need more, 50 to 75 watts is generally enough for small/medium gigs and the majority of guitar amps fall into this bracket. Choose a sensible speaker configuration, 1x12's are portable but can be 'directional', 2x12's are louder and less peaky, 4x10's or 4x12's more so, but the trade-off is increased size and weight, unless you have a roadie!It always used to be simple, valves were the real deal, tranny amps were pale imitations. But not any more, the latest solid state and digital modelling amps can sound nearly as good. They're also cheaper, lighter and more reliable than valves, and frequently pack more tonal range and flexibility. On the other hand, the classic tones most of us want come from valves. They cost more and can be temperamental, but for most professionals it's still valves first. Many manufacturers make both, as well as hybrid designs that usually incorporate a valve in the preamp.
Decide how much you can afford, then jot down the features you really need. Are three channels a luxury or a necessity, do you really need a fridge-sized rack system and a pair of 4x12's for that duo gig at the local wine bar? When you've narrowed your choice down to about three candidates, find the nearest stockists (call the UK distributors if you need to) and go hunting. Call first to check the amps you want to audition are in stock! If you can, go during the week, Saturdays are always busier, and noisier.
If you can't bring your own guitar, use a close match. Work on the clean channel first, and set up a balanced sound. Then look at where the tone controls are, if they're roughly in the middle of their travel this is a good thing. Some amps share one set of tone knobs for clean and distortion channels. When you have your ideal clean sound, switch channels and see how far you have to tweak them for that killer lead tone. Play at realistic volume levels, but be sensible, a Marshall on ten won't impress store staff! If you're after practice amps then listen to them at practice volume, most bigger amps are tuned for gig levels and can sound 'flat' in bedroom mode. Use a pedal to check FX loops, but concentrate on the tone of the amp. Don't fall into the trap of propping up an indifferent amp with a stomp box, sooner or later you'll regret it.
Listen for noise by turning everything up with the guitars volume at zero. Some hiss on lead channels is normal, and most amps hum a little. Rotate the knobs and listen for pops and crackles. Flip switches to see if they pop too. On valve amps, rap your knuckles on the cabinet, ringing or high pitched squealing indicates a microphonic valve which most shops will replace if you ask nicely. When you're done, sit back and temper your opinion with the reality that all high gain amps have some noise, it's up to you to draw a line of acceptability. If it's too much move on, it'll be worse still in the quiet of your own home, particularly if you plan on using your amp for recording.
Buying second-hand:
If you're be careful, most guitarists sell amps because they fancy a change, but there are plenty of problem amps offloaded too. Always check the chassis screws on a used amp 'cos if they're chewed up it's a sure sign of tampering. Be especially wary of buying anything more than twenty years old, and don't be suckered in by high-priced 'vintage' gear, unlike guitars, age doesn't improve an amp. Most old amps need a lot of work to make them reliable and safe to use. If the amp has a detachable mains lead, then fit a new one. If the lead disappears into the chassis then open up the plug and check the wires are secure, and the fuse value is correct. Also budget to renew old valves, a set of quality replacements can easily top a hundred pounds.Check the speaker. Give the cone a gentle poke to make sure it's firm and not deteriorating. Turn the amp on and check to make sure there's no orange plate glow on the power tubes. Don't confuse this with the normal orange glow of the tube's heater filament. Orange glow indicates that the tubes are dangerously underbiased--this isn't necessarily a failure, but would have to be addressed right away, as it might burn a tube or transformer quickly. Pull all the tubes and look at the tube sockets to see if any of them look cracked or burned. You probably won't be able to do this, but it won't hurt to ask the seller if he'll pull the chassis and let you have a look around inside. The most obvious thing to check for is burned or cracked resistors. Again, this wouldn't necessarily indicate a problem with the amp, but rather that the components are simply worn out.
Check the electrolytic capacitors for "bubbles" or residue on the ends of the cans--they'll need to be replaced, if so. It's an accepted fact that electrolytics "die" after years of use and must be replaced. Ask if the amp's been played regularly, or stored away--ironically, amps that are played regularly often sound better than those that have been mothballed, because electrolytic caps need regular "exercise" to keep from drying out. Of course, the big test is in the sound! When you plug in and turn on, be sure to give enough time for the amp to warm up (I'd try to play it for at least a half-hour or so). A 60-cycle hum indicates bad filter capacitors, which will need to be replaced. Listen carefully for crackles and drop-outs which might indicate bad internal components--often these don't become apparent until the amp is really warmed up.
Once you've parted with cash in a private sale, you've bought it 'as seen' with no comeback, whereas a shop will normally provide a reduced warranty.
Remember, most of your sound is defined by the amp you use, so it's worth taking time to make the best choice. Don't feel you have to settle for second best with a first amp, find something that inspires you and makes you want to play. With so much choice out there today, there's an amp that's just right for you, whatever your budget.
See also: Amp Myths