When you’re looking for the right amp you need to consider many factors, and it can be a daunting experience. Let’s take a look at what some features and specs mean, what they do for you and some other factors you may want to think about when going for your new amp purchase.
The power of the amp is expressed in a term called watt. The more watts, the more power. But the correlation between power and volume is a bit more complex. You may be inclined to believe that say, a 100 watt amp is twice as loud as a 50 watt one but that’s not the case. Higher wattage does generally mean more volume, but it isn’t as nearly as correlated as you might think. If you want to hit the stage, 15 watts is often more than enough. For those who prefer to use a higher wattage, the attraction isn’t necessarily volume: it will give you a cleaner tone due to an increase in headroom. Your overdriven, distorted tones will generally be tighter and your cleans will be cleaner as well, because the power stage can’t clip yet because before the power stage can start distorting, your ears will have blown up!
Tubes vs Solid State
The design of your amp can be either based on tubes or transistors (solid state). If your amp solid state it’s bound to be a lot lighter and more compact. The extra weight of a tube amp is because they need heavier transformers and other parts to make the tubes work. Tubes are a much older system than solid state: they were used as ray tubes in old radios and TV sets before they were phased out by transistors (i.e.: solid state). Generally tubes offer a warmer, smoother, more natural tone than solid state. There are many varieties of tubes available nowadays but if you want to read more about tubes, don’t hesitate to click here: an extensive description of the most common vacuum tubes. But some solid state and digital designs are approaching the levels of sonic pleasantness we’ve grown to love from tubes. Tubes are fragile: they can’t handle shocks that well and they need to be replaced at regular intervals. No matter what you choose, let your ears decide. I’ve heard plenty of awesome tones being churned out of transistor amps and equally horrid sounds from tubes.
A ‘real’ reverb system incorporates a set of springs to mimic an echo. There are many good reproductions in a digital format, so not all amps that feature the reverb have a ‘real’ analog spring tank. I wouldn’t know how to get my tone without a reverb, so when I pick an amp, I need a reverb. It gives me, at low intensity settings, a kind of suppleness that’s unavailable otherwise. I don’t need a delay-ish effect, just a bit of juiciness and fluidity. If you want to know if your amp has a ‘real’ reverb, take a look inside. You’ll see a big, rectangular tank. If you (gently!) tap the casing of your amp, you should hear a spring loading and unloading. A metallic ‘reverberation’ will be audible.
Many amps have at least two channels – clean and dirty – often with their own respective controls, or sometimes with a shared EQ. Each channel will at least have its own volume knob, and often a gain knob. Sometimes there’s a master volume after the channels, to set the overall volume of your amp. (Sometimes you even have a second master volume, so you can switch between your rhythm volume and your lead volume, either distorted or clean). Strip down to the bare minimum of what you need and use your ears. I know guys who need four channels (clean, crunch, overdrive, high gain) with individual gain and volume knobs plus tone stack per channel, reverb and dual master volumes. For them, this Mesa/Boogie Road King is the perfect tool. Others are able to do the same but with a single channel amp and some stomp boxes. It all depends on how you use what you’ve got.
After reading this article I had an even better grasp on how to use what I have. I use two heads plus a select few pedals to get my tones. For clean and not-so-clean I use a Mesa/Boogie Mark III, plus an overdrive pedal (Seymour Duncan’s 805 is an excellent choice!). For distortion and high gain leads I use a heavily modified Marshall JCM800 2210, with, again, an overdrive to boost my signal if I need super-high gain or just that extra boost for my leads. I get the same options as the next guy with a fou-channel-all-included amp but I don’t hear my tone degrading (and I get a workout, all for free, by lifting two heads, plus a small pedalboard).
A very useful feature is the effects (fx) loop. The FX loop is, in essence, a tap between the power stage and the preamp. Effects like delay, some loopers and other time-based pedals need the FX Loop because they work on the ‘completed’ tone. The FX loop can be either in series (with your entire guitar signal going through the effects) or in parallel (with the signal split into unaffected and effected streams before being recombined), and sometimes you can select between these two modes. There are many more words that can be written about the effects loop, but I suppose I’ll leave the talking to Dave who wrote an excellent article concerning the FX Loop and all of its ins and outs.
These are the most common aspects you should keep in mind and be on the lookout for when picking up a new amp. There are so many iterations, possibilities and options available, either new or on the second hand market, that I don’t feel confident enough to give a specific advice on what (or what not) to buy. All I can wish for is that you are able to make a choice and that some of the more intricate, mysterious features have been demystified. No matter if your next amp will be the state-of-the-art Kemper Profiling Amp or a vintage Marshall 1959SLP ‘Plexi,’ if you made your choice consciously (and perhaps with a bit of aid from this article), I’m happy!