Guitar/Buying an Amplifier
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The kind of amplifier you use affects the sound of your guitar. There are several kinds of amps with many different features and it's important to make sure you pick the right kind of amp for the sound you want. So how do know what you need? The first point to understand is that everything that comes out of an amp is all due to the chain of sound. This chain refers to all the factors that comprise a rig: guitar, leads, amp, effects and your playing style. If all the links of the chain are strong then you will you achieve a good sound.
- The first link of this chain is the player. It's the player's skill that determines the quality of the sound coming out of the guitar. A player whose technique needs improving will make the guitar sound worse then a player who has some technical skills, especially when amplified. Thus, accurate timing, clean intonation, balanced playing technique and optimal handling of the instrument determines the overall sound of the instrument. Almost all of the tone of the guitar comes from the guitarist.
- The second link is the instrument which the player manipulates. If the guitar is set-up poorly or has old strings; no amount of amplification will help improve the sound.
- The next link is the pickup. Pickups can sound clean, muddy, fat, or even metallic. This is especially true if you run it through a good clean channel.
- It's only after all these do we get to the amplifier. Within the amplifier there are a few more stages itself: preamp, equalizer, effects loop, power amp and speakers; all of which contribute to the overall sound. Amps also have different internal parts (tubes, solid state, digital modeling, analog modeling) and different makes of speakers and cabinets. There's also different configurations of the internal circuits and there's always some deviations in electronic parts. All these factors affect the sound of the guitar
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[edit] Selecting the Right Sound
The output tone will vary depending on the components that the amp manufacturer uses and this section will hopefully guide you through the many choices available.
[edit] Tube
Tube amps are often considered "vintage amps" because their design defined the classic sounds of the 50s, 60s, and 70s. The words, "warm, fat tone", are used to describe the jazz, blues, rock and early metal guitar sound of these decades and this is encompassed by the term "vintage amp" – the sound of Hendrix, Led Zeppelin, Eric Clapton, and Deep Purple. Most analog devices have a slight compression that is dependent upon pick attack and this smooths out the attack envelope of the notes being played; which is more suitable for blues and jazz than hard rock. These sounds can only be created by tubes and though old amps from these decades are still available to buy they may be expensive and costly to maintain due to part failure. New amps that are copies of the original vintage amps are available to buy. Examples of these include the Fender Bassman Reissue, Epiphone Valve Junior and Marshall JMP100.
Tubes amps have a very organic tone and are sensitive to their input signal. The harder you dig in with your pick, the more they tend to break up and distort. The softer you strum, the warmer and breathier they appear to sound. This is known as touch sensitivity. Multiple preamp gain stages can sometimes push an amp to the point where you do not hear the pick attack on the string. Finding a balance where pick attack and sustain are clearly articulated is the sign of a superior matched preamp and power section. With a great tube amp, the subtle changes you make with your pick and finger pressure can be heard so that you can create your own identifiable style.
Of course, tube amps are not without drawbacks:
- A tube is based on vacuum technology and requires more energy given the same wattage as a solid state amp.
- Vacuum tubes are expensive and require replacement every one to four years, depending on use.
- Due to the need for a transformer on the power amp, amplifiers using tubes are generally heavier.
- Tube amps are also more expensive to buy than a solid state amplifier. An Epiphone Valve Junior Combo with only a volume knob and one input and one speaker is even more expensive than a Traynor DynaGain 30D (A very good analog modeling amp) by $50 CDN.
- Tubes require a warm-up period before they sound their best.
Within tube amplifiers, there are also three different types of operation: Class A, Class AB and Class B. However, Class B is virtually never used in guitar amplifiers and so will not be discussed.
- True Class A works by having the power tubes running at full power, reguardless of actual sound output. Class A is charecterized by a smoother, sweeter distortion. Most class A amplifiers use a single output tube. Thus, the wattage is generally low, as class A by itself is inefficient. Furthermore, the fact that current constantly flow into the tube will make the tube have a shorter lifespan. Due to the low efficency, mostly only low wattage amplifier, such as Epiphone valve junior or Fender champion 600 use true class A; the typically wattage, is no higher than 5-7watt RMS per power tube.
- Class A can also use a pair or a quad of tubes for more power. A good example of this is the VOX AC-30 or Orange Tiny Terror. These amps, while still Class A, have the tubes operating in opposing pairs, called Push-Pull. Typically, when the power tubes are cathode biased, they are labeled as class A.
- Class AB work by using a pair of tubes, with one always working for the "positive" voltage and another always for "negative" voltage. Due to the nature, class AB is thus more efficent, and has slightly longer tube life. It also have more headroom if needed. Class AB has a different sound than Class A. Class AB, by being push-pull, has less distortion and has a cleaner tone at lower volumes. When pushed into overdrive, it will have a more abrupt transition into distortion than class A. Marshall, as well as many other high power amplifiers, use class AB. In fact, most of the famous Fender amplifiers are class AB.
Both are respectable to even the most hardcore tube enthusiast. However, most will agree that tonally, class AB is less dynamic, and thus is less suited for blues and jazz, but good for high-gain guitar styles, such as hard rock or metal.
[edit] Solid State
While it is debatable when solid state amps became most popular, typically it is associated with a hard rock sound. Some attribute this to Eddie Van Halen and his modified Marshall, which allow him to have more gain, and deliver a more in-your-face tone and volume when overdriven. Solid-state amps also have a fast attack time, where the note is immediately present when strumming. They also have the benefit of not needing to warm up, unlike tube amps, which requires 15-30 seconds minimum to play and 30 minutes to an hour to sound their best. This means you can just plug and play.
When played cleanly, solid-state circuitry provides a powerful sound, making it very suitable for jazz or acoustic music. Solid state provides a wide-frequency reproduction, especially with large speakers that provide a full bottom and smooth high end. Examples would be Fender's Jazz-King and Steel-king and the most famous jazz amplifier, the Polytone Mini-Brute. A good quality solid-state amplifier can still provide richness, depth, warmth, color, and dynamics. Those that use FET transistors on the preamp stage are considered to reproduce all these desirable characteristics. Solid-state lends itself to guitar styles that use effects combined with the cleaness of the signal.
Solid state amps are effective because they can take very high gain, and this is used most effectively in heavy genres, especially metal; this is because that at a certain distortion level, solid state amplifier allow a lot of tight Bottom end.. Breaking from the traditional Marshall tube stacks, more and more metal musicians discover the benefits of pure solid-state amplifier, especially those with no build in modeling. Examples of such amps are the Randall Warhead and Fender MetalHead, which at high voltage provide much more gain than its tube equivalent. Basically, they emphasized upon the philosophy of "going to 11", with extreme distortion and extreme loudness. Playing this kind of ultra-high gain amps require a pair of earplug, especially at high volumes.
The most important benefit of Solid State is simple: it's smaller, lighter, and cheaper. Examples of these include Crate's CPB150, Fender's Ultralight Series, and ZT Lunchbox. All these are less than 10lb but output more than 150 clean RMS sound, and with proper pedals will sound well as a backup amp.
[edit] Modeling
A deviation of solid state that attempts to mimic the gain-compression on a Valve-based amp, it is basically a combination of a very clean power amplifier and a tone modeling unit producing most of the tone. Some may consider this as the swiss-army knife of amplifier. The best of these amps can roughly mimic the sound of many other units with acceptable accuracy, and quite often than not also have cool effects that make even bad guitarists sound acceptable - delay, chorus, flanger, reverb, etc. Again, there's no substitute for skill.
There are basically three kinds: Analog circuitry, Dedicate DSP, and modeling processor (typically also have many digital effects onboard). Analog circuitry and dedicated DSP are typically the best kind, while modeling processors seems to have a bit of a lag between your pick attack and the sound produced, and you should test one carefully before buying it.
[edit] Hybrid
Another attempt to provide a valve sound with a solid-state speed is to use a Hybrid approach, which have the following configurations:
- Tube preamp, solid state power amp
- Solid state preamp, tube power amp
"Solid state" here also include modeling, be it analog or DSP.
Typically, metal players prefer the tube preamp with solid state power amp, believing that it would provide the tube tone with a fast attack. However, in numerous blind test[1][2], one cannot differentiate between a tube preamp and a solid state preamp, but it is easy to spot whether it is tube or solid state in the power amp. Thus, it was said that one that use tube preamp is no different from a normal solid state power amp, while a well made tube power amp is as good as a true tube amplifier. This is another reason why more and more metal player prefer complete a solid state amplifier with very high wattage.
When using a solid state preamp, particularly of modeling preamp, it provides the versatility of high gain sound while allowing power tube distortion that actually makes it warm and fat with compression of the sound. However, some believe without any tube preamp gain, it will be less warm compare to a true tube preamp.
In order to counteract the aforemention deficiency, a recent trend is to include both a tube preamp and a tube power amp, and couple this with solid-state circuitry. There are two approaches to this:
- all-in-one single-tube circuitry containing both tube preamp and tube power amp, between solid-state preamp and solid state power amp. this is employed in the Vox Valvetronix system. As it typically use a dual-triode tubes, usually designed only as a preamp and not power amp purpose, it is often questionable whether this provide the necessary tube gain.
- Provide some tube preamp gain before feeding into the tube power section, with at least one triode gain stage. Example includes Line 6's Spider Valve, and Fender's Champ XD series; as both are coupled with a modeller, such scheme provide traditional tube sound while having versatility of a modeler.
[edit] Physical size
Just because you can afford to have a very powerful amplifier (in both money and wattage) does not imply you should get said amplifier. A problem for the traveling musician is that you can be very limited by your amp size. For a high wattage, you will have to pick up a big amplifier that can be too cumbersome to carry, while a small enough amplifier may be bad for even a normal jamming section, let alone gigging.
Also, consider your practicing space as well. For example, if you live in a small apartment, you may have to get a smaller and weaker amplifier. Aside from obvious quieter sound, the smaller physical space available may also make storing even a full size 1x12 amplifier difficult.
In another example, Traynor's TRM30 (1 x 10" x 30w) and TRM40 (2 x 8" x 20w ) are both good audition amplifiers. However, the TRM30 is taller, while TRM40 is wider. Furthermore, TRM30 is at 21 pounds, while the TRM40 is at 34 pounds, about one and a half times as heavy. Considering that some people may have to carry their entire recording setup — a laptop, effect units, guitar— the slight difference in mass and dimension may make the difference in the ease of carry.
(Sidenote: If you do have to carry a guitar, amplifier, laptop, and school stuff, get a 5 watt amplifier, such as Vox DA5 or Epiphone Valve Junior. It's small enough to be carried, and as long as your jam buddy understand, it's still loud enough somewhat. Otherwise, just bear with the weight.)
[edit] Typical features of an amp
[edit] Essential
- Input - where you guitar cable goes in
- Power - turn it off and on
- Volume - adjusts the volume, and at higher levels, how much distortion
- Speaker or Speaker out - where the sound comes out. For speaker out, never plug in a speaker out port with a speaker that has different ohms than what's labeld on the jack (eg, 4 ohm or 16ohm into 8 ohm)
An amplifier that only has these is Epiphone's Valve Junior and Fender Champion 600, both are consider the cheapest new tube amps on the market.
[edit] Almost standard
- Gain — determines the amount of distortions. The higher it goes, the more overdrive it has.
- EQ / Tone - Used to control the tone of the sound. May have only 1 knob (simply general tone) or two (treble and bass), but some even have a 7 band EQ that not only control treble, midrange, and bass, but also other including prescene.
- Phone output — used to plug in headphone so you can practice in the middle of the night.
- Channel selection — most modern solid-state practice amp have two channels or more channels; one for clean signal, and one for an overdriven output. Many of the more expensive tube amps have multiple channels as well.
[edit] Other stuff
- Additional inputs: On higher end amplifiers, there could be more than one inputs. Some are merely doubling the inputs, while some may have a high and low input; low is for low impedance inputs (eg guitars with active pickup). One way to get a cleaner signal from tube amps is thus to plug into the "low" input; conversely, to get distortion earlier on, plug into the high input.
- Modeling - One way to solve the clipping problem in solid state amp is the use of DSP modeling, which allows one to play tube-like overdriven sound.
- Extra effects — some units have build in effects, such as reverb and chorus, which can be easily controlled right on the panel by one or more knobs
- Effect loop — can be a single plug (and need to be split), or separate plug as "effect send" and "effect return". Used for time-based effects (delay, chorus, looping, phase shift, and flanging), as using the effect loop will preserve the sound and effect of the amp.
- Line in, 1 or 2 — used to plug in external audio sources. they come out without passing through the preamp, and thus just louder.
- Line out - used to connect to another power amplifier or PA system.
- Speaker out - connect to another guitar speaker. Typically only found in head units, but some combo units have them too to provide flexibility in speaker choice.
- Footswitch plug — allow the use of footswitch to control internal effects, or may even select channel.
- Impedence switch (on tube amps only) - allows you to change the impedence of the speaker out jack so you can plug in speakers of different impedences.
- Standby switch (on tube amps only) - allows the tubes to warm up before turning on the high voltage required for operation. This greatly extends tube life. Also functions as a mute switch if needed.
[edit] What makes a good amp?
When you buy your amplifier, the shop owners (most who play guitar themselves) may say something along these lines:
- A tube amplifier is always better than solid state amplifier.
- Digital amp/effects are the poor man's substitute.
- A good amplifier makes all the difference in terms of artistic skill.
These are more or less true, depending on the style of music you wish to play.
A solid state amplifier can provide a good tone. In fact, many pedals that are designed to create a metallic tone is designed to use the hardclipping functions that the solid state amps provide, one thing that tube amps cannot do well. Solid state also makes for a great budget amp, as they are often many times less expensive than an otherwise equivelent tube amplifier. Also, for styles, such as heavy metal, a solid state amplifer is better suited for the edge that these players are looking for.
However, a solid state amplifier has not yet been able to recreate the dynamic feel of a tube amp. While a solid state amp can get fairly close in tone, it's many times harder to influence the tone simply by how the guitar is played. A good tube amp will distort on command when digging into the strings, while a lighter touch cleans everything up with seemingly infinite levels in between. Where as, a solid state amp usually requires adjustments to the controls in addition to playing style to have any effect on the tone.
The most important thing to remember is that many of the famous artist just make do with whatever equipment they have, which often is seen as "poor quality". Nirvana used PA amplifiers as this was all they could afford at first. Many artist started out and keep on using cheap Danelectro guitars, which use plywood for body. Hendrix is said to start out with a severely battered acoustic. Thus, in the end, the players makes the tone, and the player decide whether the tone is good or not.
Digital effects are used prominently by many big name artist running solid-state amplifiers, which provide clean tones. Some say that effects are best suited for solid state amplifiers. Ultimately, what sounds right depends on the player; after all, no matter how good a equipment, a poor player will still show his poor skill, while a good skillful player can turn even the "worst" stuff into something decent.
Keep in mind that a the bigger the amp, the more the commission the saleman makes. Remember that bigger is not always better.
[edit] Size and Wattage
How big? How many watts? How many speakers? If you are just starting out, you should think carefully about where you want to go in the future with your music, and buy appropriately. As a general rule, doubling the wattage will only increase the volume by about 3db. 3db is not a large difference, however, don't forget that these 3db may make all the difference in a loud band. Multipying the wattage by 10 (ie, 10 watts --> 100 watts) increases the volume by 10db and is perceived as doubling the volume. Many other factors effect final volume including type and amount of speakers, as well as overall tone of the amplifier. For example, doubling the amount of speakers will result in a 3db increase. As well, a really bright sounding amplifier will cut through noise better than a dark sounding amplifier so not as much power will be needed if your amp is bright. 25 watts into a 4x12 cab will be as loud at 100 watts into a 1x12 cab. This is one reason full stacks are so loud, because 100 watts into 8 12in speakers is like 800 watts into 1 12in speaker.
[edit] Speaker configuration
Your two main options are single speaker units, and multispeaker (often 2 speaker) units. Most 2 speaker amplifiers, ranging from the smallest 50 watt combo amps to the MG15MSII "Microstack" offered by Marshall, have basically have the same amplification circuit of its single-speaker siblings. Sometimes, such 2 speakers configuration may use smaller diameter speakers than their single speaker cusin (eg: 2 x 10 inch instead of 1 x 12 inch).
The main benefit of having multiple speaker is that it increases volume as well as bass response without sacrificing the higher frequencies. By having more speaker cones, the speakers will move more air. For example, a 2x10 have the surface area of 157sqin, while a 1x12 only have 113sqin. A 4x10 cab is often used for large combo amplifiers as it provides most of the bass response you'd get from a 1x15, but retains the high frequency that the 1x15 can't produce. Also, it will have increase power-handling capability, or more precisely, they split the amp output. Thus, given same amplification head, a 2 speaker configuration will have louder volume, but only half the power to each speaker. This has yet another advantage.
All else being equal, generally a low power speaker is louder at the same power as a high power speaker. This is known as efficency or sensitivity. A 25 watt speaker with a 10 watt amplifier will generally be louder than a 100 watt speaker on the same 10 watt amplifier. Thus, a multi speaker cab will allow the use of low power speakers with a high power amplifier. The original Marshall full stack used a 100 watt amplifier with 8 25 watt speakers.
Lastly, in some styles of music, such as rock and blues, the speakers sound their best when being pushed close to their max power ratings. When buying cabs for your amp, the best power rating is about 150% of your amp's rated output. 150 watt for 100 watt amp, 75 for 50, etc. Any higher and you'll actually loose volume. For harder music, pushing the speakers that hard may cause an unwanted smoothness. If money permits, buy cabs rated for 2-4 times as much as the amp.
[edit] Wattage amount
While on the surface, higher wattage means better amplifiers, in reality this isn't true. For example, many 100 watt amplifiers can be too loud when turned up high, and thus the user automatically lowers the volume and try to compensate with more gain. However, it may sound better by having a 50 watt or even 20 watt amplifier, which allows less gain but higher volume, producing the same amount of final volume. Guitar amps are a lot louder than their wattage lets on to. Some guitarists have used 5-10 watt amplifiers successfully on stage. The norm is closer to 20-50 watts. However, each amplifier has a unique tone. If volume is the only issue, consider placing a Sure SM57 mic in front of the speaker and running that through the PA. Many artists use suprisingly small amplifiers (1-5 watt) in the studio because of their more managable sound levels.
Also, due to the way tube amplifiers and solid state amplifiers distort, there is a perceived difference in loudness, with tube sounding louder given the same wattage. The truth is that both are equally loud, but the sustain on solid state amps is not as good, which results in a perceived lose of volume. If you are gong to be in high overdrive all the time, solid state amps will actually sound louder, but often more piercing.
Another question is whether you need the louder wattage. On one head, doubling wattage only increase 3db, which is not a lot in that case. On the other hand, in order to push the lower frequencies of the sound, wattage is important. This is because the idea of a good distortion, in general, is to have an amp that push as much clean bottom end into your overdriven sound as possible without getting flabby or muddy, which is what creates the hugeness of the sound. The lower in wattage that you go, the quicker your bottom end will mud out. This is not always the case.
As a rule of thumb, the amount of wattage need for Solid State amp is of follow:
- 10-30W: practice on your own.
- 30-50W: practice with a band or recording; gigging (small club)
- 50 to 100W (or more): Large Gigs (as much wattage as you ever need). Even using that 500w MetalHead amp for your blues music could be necessary.
For valves, it's a bit more complicated:
- <10W clean:, Self Practice, Recording
- <10W overdriven: Self Practice, Recording, Gigging (small club)
- 10-20W clean: Self and Band practice, Recording, Gigging (small to medium club)
- 10-20W overdriven: Band practice, Recording, Gigging (small to medium club)
- 20-30W: Band practice, Gigging
- 30-50W: Gigging
- 50W-100: Freakin loud. Please use a pair of earplugs.
- 100W+: Earthquake and noise pollution. Prepare to deal with the police.
[edit] Power Ratings
When reading an amp's rated watts (this is more the case with solid state amps), not all manufacturers adhere to a universal standard in stating the wattage. For example, an amp manufacturer may say Amp A is rated at 400 Watts. But when you go to an oscilloscope the measure its true wattage, you may find that it is only a 100 watt amp. But at several points of the sound wave it may have spiked (transients) up to 400 watts. So, the manufacturer goes with the max reading. On the other hand, more than a few 100 watt Marshalls (and other brands, I'm sure) have tested at 150 watts clean. Distortion compounds this problem. Due to the nature of distortion, tube and solid state alike, the amp might be putting out 100 watts, but the speaker sees it as 140 watts (see short explanation below). This is why it's important to buy speakers rated for more than your amplifier is rated.
RMS is .707xPeak voltage. In distortion, the sine wave becomes a square wave, resulting in a power output that is closer to the full peak voltage. A 100w RMS sine wave has peak voltage of 141.4w
[edit] Types of Unit (smallest to largest)
The combo amps is an one piece unit containing both the preamp, power amp, and the speaker(s). Typically they do not exceed more than 100 watts, are they are designed to be "relatively" portable. Most combos have just a single speaker, ranging from 6" to 15" but some have two or even four speakers. The most common is a single 12" with a pair of 12" being the next most common.
[edit] Micro/Headphone amps
Usually 1 watt, and do not exceed 10 watts. This class of amplifiers are known for their small size (no larger than a computer speaker), designed for extreme portability (such as carrying them in your guitar bag). While some may have built-in speakers, they usually cannot be heard during Jam sessions. As they are solid states and generally low wattages, if they do not utilize FET circuitry they tend to go into an unpleasant distortion very quickly. Aside from homemade solutions (such as the famous Ruby amplifier), Danelectro Honeytone and Vox amPlugs are all good choices.
[edit] DI Unit (including amp modelers)
Many "amp modelers" or "micro-amps", like the Rockman, are actually DI Unit hybrid with effect units. A DI unit transforms the unbalanced, high impedance signal from the guitar into a balanced, low impedance signal for use with a mixer; however, some desiged for use with guitar have amp modelers within them, and may have multi-effect processors for additional effects. Most often these are used with headphones, but they also allow direct input of the guitar to the mixing desk in a recording studio, while retaining some of the tone and quality of an amp. There are two kinds: analog modelers, which is most common, and digital computer modeling, such as Line6's POD 2.0.
The main benefit of using a DI unit is that they are compact, and they can get "loud enough" and have a particular tone. This is particularly true for amp modelers and "headphone amplifiers", as their embedded electronics frequently have a somewhat decent approximation of a tube amp. You can also use these in recording, or use it like a pre-amp and plug it into a larger amp for volume. Also, if you are often going to hook up to a P.A. system with your amp, these may provide a cheap option and quicker setup than a larger amp. The Behringer V-Amp 2, is a good example at less than $100 USD.
The main downfall of DI units is that they cannot completely capture the tone of a guitar amplifier. The ultimate way to connect an electric guitar to a PA is to use a microphone in front of the speaker.
[edit] Practice/Studio amps
Their wattage may range from 5 to 50, though from 30 on it's hard to say whether it is purely practice alone or can also be used for small gig (see below). Generally, they are designed to be used in a small space, because the small size demands a small space for a suitable volume for practice or recording. While they come in various size, for a solid state amplifier, one should need at least a 10-inch, suitable for jam sessions. On the other hand, if you have a 5 watt tube amplifier, most people will accept your amp in a jam session.
[edit] Small gig amplifiers
From 30 watts upward, these combo amplifiers the smallest package which is considered suitable as a stand-alone amplifier for small gigs. The standard is usually 50 or more watts of power and one 12 inch speakers, though some manufactures may use less wattages of 30 and 40, while employing more than one speakers. For tube amplifiers, even a 30 watts is enough, though with better models, sound quality of solid state amplifiers begins to approach levels acceptable to professional musicians.
Quality is always important, but perhaps even more so in the case of the 1x12 inch combo - with a good one, you'll prove the doubters wrong, but with one of the many duds, you won't be taken seriously. The 1x12 is not a big amp, and if you want to bring it to a serious audition or gig without enduring a storm of eye-rolling and chuckling, it had better stand out from the crowd. These cost about 180 to 450 USD.
While a 2x12 combo may be seen as simply an amplifier with one more speaker, the volume of air moved essentially double, and thus make it louder. Benefit of using two speaker instead of one is that it allows stereo effects. Some consider these to be the absolute minimum serious amplifier.
- Busking amps
In essence, these are practice/small or gig amps that have a battery attached. Naturally, that means they are more expensive. 15 watts on average, but Pignose Hog 30 can go to 30 watts, while Vox's DA20 have 20 watts and 2x 8" speakers, and Crate's Taxi Series have some that have 50 watts with 10 inch speakers.
They will usually provide 6 to 10 hours in one charge, but also, make sure they can take AC power too when needed. Do note that they are actually quite weak in terms of overdrive. On the other hand, rock and metal music is not exactly busking music, either — soft and light music that add to the atmosphere (usually a park or something) is usually preferred, and thus, the watt are usually enough. A good one is Vox's DA series, which uses modeling processors for an approximation of a tube amp while having a small package.
[edit] Heads, Cabinets, and Stacks
One of the greatest symbol in rock and metal is the stack combination basically, it was made up of the following:
- The head: Basically the amplifier without the speakers
- The cabinets: Contain the speakers in an enclosure
Due to the fact that they are always at least two pieces (even if they can be locked together), they are bulky and not really known for their mobility.
When purchasing the two, make sure of the ohmage of the cabinet, and the power rating for the head at that ohmage. Make sure the cabs RMS rating is about the same as the head's power output at the ohmage of the cab. A head can be solid-state or tube, the latter being less durable, but sounds better and is more expensive. A good solid-state head costs 200 to 600 dollars and a good tube head costs 500 to 1400 dollars. In general, a single cab would have a 4x12 for guitar, though other arrangements, such as 1x15, a 2x12, a 4x10 or a 6x10 had also appear. A cab typically range from 250 to 650 dollars.
[edit] Low wattage
Why would someone want to make an amplififer with low wattage, which is usually 5 to 15 watts – making them practice amplifiers, but in a stack format? Some of them, such as MG15MSII by Marshall, is a mere showpiece, for people who wants to own a stack but do not have space and room for one. While they may be in a stack configuration, these low wattage solid-state heads are still nothing more than a practice amp, and depend upon who you are talking to, they may even invoke an image of wannabe. Then again, Zakk Wylde use a modified Marshall MS15MSII microstack (now available as Microstack Zakk Wylde edition) for his practice, which when played by the demo person (see it in Marshall theater), is quite well for a metal sound.
However, for many <20w tube amplifiers, such as Epiphone Valve Junior's Stack configurations and its numerous clones, such as Crate Blackheart BH5H, or the Marshall 20w Lead and Bass Head, it provide much flexibility that cannot be provided in a combo. A hot rodded class-A tube amp– which can go up to 16 watt RMS with 2x 6v6 and proper output trnsformer, pumped out a 4x12 cabinet, can be as loud as a 50 watt solid-state amp, and thus it provide potentials to upgrade in the future. Furthermore, by seperating the speaker from the amplifier, customizing (hotrodding) the amp is actually easier than a combo. Since pumping through more speaker produce more volume but have a softer sound, it may be even better than a fully cranked 50 watt tub amp during a performance. By seperating amplifier into two piece, it could also be easier to carry, as in the case of Orange Tiny Terror (15 watt), which comes with a shoulder bag. This is due to how human bear a load: the same piece of equipment could be very heavily or "lightweight" depend on where (on the body) and how you carry it.
[edit] Serious gig
These are the types that most people talk about, with a head unit of wattage from 50 watts that's good for a small club, to the standard 100 for large auditorium. For a small auditorium, a half stack – connecting to one 4x12 speaker cabinet– is more than enough, and still can establish creditability of seriousness.
For larger avenue, or even arena, you may run a full stack – that is, you have two 4x12 cabinets, one stacked upon another vertically. The size, however, is tremendous; when fully deployed they are as tall as a grown man, and even when disassemble, you will still need a van to carry them. In case the volume is not enough, you can either hook up to even more speakers, or better yet, use another stack as a slave.
Obviously, these are not really good for practice, as not only are they hard to transport, but also too loud. My neighbor received a notice for turning his half stack a bit too high, and I start to get uncomfortable on volume above 2.
One that is good is the Crate's PowerBlock, which is as small as a DI unit, but is actually a 150watt RMS pure solid-state goodness. Plug in any FX you want, and you will have a perfect companion for your guitar.
Unless you need extreme loudness, you probably won't need these 200+ watts amplifiers. On the other hand, that 550watt Fender MetalHead is definitely tempting (it's $900 USD), and so is the Randall Warhead (300 watts). Oh well, if you want metal, you can always just go for the Warhead Combo configuration.
On a sidenote, ALWAYS WEAR EARPLUGS when playing a full stack. In fact, MetalHead have a nice container that is designed for holding earplugs.
[edit] Head and cabinet match up
As mentioned before, a speaker out will have a certain acceptable ohmage, and you should only plug in speaker that have the same ohmage, even though larger amount of ohmage is also somewhat acceptable (eg: a 8ohm plug can only accept 8ohm or 16 ohm) Pluggin a speaker with less acceptable ohmage will burn your amp.
Furthermore,having more speaker only increasing the volume somewhat; using a 5w to push a 4x12 cab will be slightly louder than 1x12, as you can push more watt thropugh such cab, and you'll have a broader tone, with the sound thicker and fuller. However, to actually increase the volume, you do need more wattage into the amp
[edit] No amp here!
One of the iconic image of heavy rock and metal is a "Wall of Marshall" standing behind the entertainer. However, chances are that only 4 of these speakers (a double stack) are real, if at all. Some artists may even use amp modelers in secret. Brian May, for example, uses only 6 Vox AC30s even though he has a "Wall of Vox"
In fact, as howstuffworks pointed out, when you have a PA system, you are more likely to run amp modelers into it.
[edit] Rack-Mounted Products
The rack mount units is the ultimate setups for live arena playing, which offer maximum controls of the tone without sacrificing the tone. As named, these units are mounted on standard 19-inch racks, and as they are in separate components, the guitarist can select the tone they want, as well as decide how the things are wired up, in a nice organized package.
As mentioned, rack mounted products are made up of many individual components, such as a pre-amp unit, equalizer, speaker/cabinet simulators, power amplifiers, power unit, and even tuners, MIDI switchers, and etc. As these are individual components, they allow multiple distinct sound chains that may share some components and branch off for some other tones, as well as numerous routing options that can be more complex than those offered by a standard stack setup. This provide the benefits of providing the desired tones that can be stereo or mono.
Quite commonly, these are all controlled by a MIDI pedal, plugged into the MIDI switcher.
[edit] Advantages and Disadvantages of Rack Rigs
[edit] MIDI and USB
[edit] Tips
- Like Guitar, buy it with not what the others said, but by your own judgement. Sound easier said then done, though: for example, the review for the MS15MSII (you can see it on Marshall's website) is very different from those user reviews on Harmony Central. If you want a more honest opinion, get the user reviews.
- Different players will have different taste. Dimebag and Maximum the Hormone use solid state amplifiers, which is often seen as cheap junks for most blues and rock players. Then again, most people dislike Metal, so...
- Better to buy a good quality amplifier than to buy one that's cheap; there are actually better long term investment in this case.
- For most beginners, a 15 watt solid state amp, or a 1 watt true tube amp, will be more than enough for your bedroom and small gigs.
