Whether it's a small portable amp, large 4x12 or a simply a valve head. The choices are seemingly endless. So we decided to put together a guide covering the many options available and try highlight some of the features which make each unique.
In real simple terms amplifiers come in several forms valve amps, transistor amps & modeling amps. These in turn can be a head and cab, a combo ( or combination of head and cab) amp. There is even acoustic amps and even mini amps to consider!
Major companies such as Orange cater for all different needs: from Valve amps ideal for professional gigging players to solid state practice amps, and even mini amps. View Orange Amps here
There's no "right" or "wrong" amp, actually, because it always depends on your personal tastes, on your ear. But here's a few pointers that will help you look in the right direction anyway!
Beginner / Just playing at home? If you're just a beginner, a mini amp might be enough for you. For playing at home, either beginners or even experienced players don't need anything bigger, better or mor expensive than a sub-£100 guitar practice amp.
Busker? If you're a busker, you're better off with an amp that does not require a power supply. The Roland Micro Cube is a great little amp, very popular with buskers who require amplification due to its portability, cheap price and the fact it can be powere by batteries! It's pretty loud, too!
Recording? The best amps for recording WON'T be big, 100-watts Marshalls, for instance! On the contrary, small amps are the best choice. We're talking about small valve amps, here. That's because, unlike with bigger, louder amps, you can crank up small valve amps, pushing them to tone heaven. If you did the same with bigger amps, it wouldn't work - you'd sound so loud you wouldn't be able to make a good recording! This technique has been used by many, many top artists. Despite using big & loud marshall amps onstage, Jimmy Page used a small Supro valve amp on the early Led Zeppelin albums. Likewise, the Arctic Monkeys used an old Fender Champ on most of their debut album.
The best small valve amps for recording that we have are: Fender Super Champ X2, Blackstar HT-Metal 5, Fender Pro Junior III, Blackstar HT-5C Valve Combo.
Playing Small Gigs? If you play small gigs, such as at pubs, clubs etc, small places with capacity of 200 persons or less, you won't need a massively loud amp. A 15-Watt Valve amp will be more than loud enough, such as the Fender Blues Junior or Vox AC-15. You can use louder valve amps, such as a Vox AC30 or Fender Hot Rod DeVille, but in most cases you won't need to set the volume more than halfway up (or less!) Valve amps sound louder than solid state amps, so even though a 15-watt valve amp is loud enough fro gigs, a 15-watt solid state amp will be only recommended for home practice. Good solid state amps include the Orange Crush PiX 35LDX and Blackstar ID:30TVP 30W. Both are loud enough for mid-sized venues and sound superb.
If you're in a small, unsigned band, it's very important to choose an amp that's loud enough - as not every venue will mic your amp. Ironically, bigger artists don't need to worry about this, since they are safe in the knowledge they'll always have a good sound and their amps will always be mic'ed. That's why Seasick Steve plays a small Roland Cube amp, but it's not necessarily a great choice if you're in a band who plays live.
Valve Amp or Solid State Amp? There's no right or wrong here, but, for tone alone, valve amps are way better. If you can afford a valve amp, just go ahead and buy one! They're the amps all the great bands ever used - from Beatles and Rolling Stones to Arctic Monkeys and Radiohead, 99% of all professional musicians simply prefer valve amps, like the Vox AC30 or Fender Hot Rod Deluxe III. But there's nothing wrong with solid state amps - the audience at a gig wouldn't be able to tell the difference.
Solid state amps have many advantages: they are cheaper, lighter, and require less care than a valve amps (which eventually will need new valves, for instance!). Vox, Line 6 and Hiwatt make really good solid state amps that you can gig with without worries. They are not necessarily "worse" amps. The Rolling Stones, Status Quo and many other big acts have used solid-state amps at some point. They're also quite popular with jazz guitarists.
FX or no FX? Again, it's almost a question of valve or solid state, here. Most valve amps don't come with any effects other than tremolo and reverb, at most. Solid State amps often come with a wide range of features such as digital FX and amp modeling. If you're an have lots of fx pedals, you don't really need a modeling unit, but if you're new to guitar playing, buying an amp with modeling FX might be a good way to get familiar with all those sounds.
Combo or Head + Cab? Again, this is a personal choice. It's easier to have a combo, but a head + cab combination might be easier (& lighter) to carry, as you can carry both parts separately. Of course, if you're in a metal band, you simply MUST use a really loud head amp (no matter how small the venue is) and a 4x 12" speaker cabinet. That's just how it is...it's in the rock bible, somewhere!
Here's our top picks...
Laney have perhaps made the ultimate studio/home practice amp with the Ironheart. Recording outputs, Reamp Inputs, 15/1 Watt selection and pure valve tone. The Ironheart has been picking up plaudits everywhere and rightly so. Will cover most smaller gigs nicely as well.
Night Train is one sexy beast. Solid enough to inspire confidence, Night Train weighs less than seventeen pounds - and the “armoured lunchbox” dimensions provide extreme portability. Finished with a cool chrome mirror-finish, the signature VOX diamond design reveals that inspiring vacuum tube glow. And of course, the Night Train NT15H includes its own padded carry case to protect your investment.
Marshall JVM410H Head
Designed for serious guitarists, the Marshall JVM410H guitar head delivers 100w of sheer tube power. The four channels and amount of controls makes this extremely versatile and allows you to get any tone you wish, with more of that Marshall gain than ever before. Gigs, arenas, and even stadiums - the JVM410 can handle it all and more.
Blackstar HT Metal 1H
The Blackstar HT Metal 1H is the perfect guitar head amp for metal players. With 1 Watt and two channels, this is an extremely versatile amp that allows you to drive the ECC83 and ECC82 tubes when playing in the home/studio for top results.
Small, loud and already legendary, the Orange Tiny Terror is without any doubt one of the most popular head amps we sell. Why? This very versatile workhorse won't let you down in recording sessions or at gigs, and it's quite affordable, too! The Tiny Terror is ideal for any guitarist seeking professional grade tube tone at a price range that won't break the bank. With 15 watts of available Class A valve power, the Tiny Terror is a highly versatile workhorse suited to a myriad of guitar playing scenarios.
Nothing screams rock quite like a Marshall half stack. This is an affordable entry to the legendary British cab, with specially selected speakers.
The two 12-inch G12 Anniversary Model speakers were specially manufactured in commemoration of Celestion’s 70th anniversary, and are a great choice for delivering the NT50s distinct clean and crunch tones. The V212NT’s retro look and rounded corner design make it the perfect companion for the Night Train 50, exuding a powerful presence on stage.
Featuring Blackstar Blackbird speakers, it's the ideal compliment for the Blackstar ID series head but will partner equally well with any head you choose to place on it's shoulders.
It needs no introduction, the Marshall cab has graced stages of probably every country on the globe. When only British Celestion speakers mounted in a Marshall cab will do...
There are many guitarists who are quite happy to plug their head into any cabinet they can lay their hands on. It's a pity as you only need use your ears to realize the difference the right cabinet can make to your amplifier's sound. Too many manufacturers compromise their cabinets by using inexpensive speakers. This foolhardy decision can be disastrous!…
Introducing the new Valvetronix+ Series – the latest in Valvetronix evolution, featuring 99 ready-to-play presets, a massive infusion of effects, plus an all-new Power Level control.
Orange have long been master of valve tone but recently an increasing number of affordable solid state amps have come with the distinctive Orange livery. They don't put out an amp unless it delivers on tone and the Crush is no exception. With plenty of effects and reverb to play with when you're practicing.
Some amps just hit that sweet spot, loud enough to gig but with master volume control to keep things down at home. Throw in footswitching, reverb, plenty of EQ options and you've got an amp fit for stage, studio and home. Blackstar are a newish name but their reputation has soared quickly, with glowing reviews and endorsements from the like of Richie Sambora, Bob Mould & Gaz Coombes.
Fender amps are relied upon by guitarists of all stripes for great valve tones. The Blue Junior will cover you nicely small gigs but also let you crank it up and get some famous Fender crunch at home, without shaking the foundations.
The Vox AC-30 is quite possibly the most legendary guitar amp ever made, used by everyone from The Beatles and Rolling Stones to U2 and The Libertines. The AC30 CC2 updates the legendary amp with new and improved features - a guitarist's dream amp, no less! The new VOX AC30 Custom Classic…
Our Top 5 Modeling Amps
For practice, tone, playback and recording the Cube series is hard to beat. Integrates with iDevices for playing along with music and gives you all the effects and amp sounds you need in one place. Lightweight compact the Cube 80GX is also a great gigging solution.
Deep editing via PC means you can get any amp sound you want from the Mustang. A powerhouse of modelling tone.
The new ID series from Blackstar is turning a few heads, using the valve power rating system so 30watts is plenty for gigging. So true valve power and tone but without the upkeep, hassle or bulk.
Another versatile beast from Yamaha, the THR delivers real tube tone, deep editing, practice functions and portability. Has a funky glowing valve light in their, coupled nicely with some retro future stylings.
The Peavey Vypyr 15 features 25 amp channel models -- both the clean and distorted channels of 12 popular amps for the first time anywhere. With external playback options, USB editing & headphone out the Vypyr is also a perfect practice amp.
The Ultimate Amp for Travelling Musicians If you're a musician who's on the move, the new CUBE Street is for you. Whether you're running to a rehearsal, lesson, street gig, or any situation that requires portability and versatility, the CUBE Street is a battery-powered marvel that's ready to travel fast. The CUBE Street sounds amazing and is capable.
Historical Background of guitar amps
Rock music evolved from Blues, the music of the streets. Most musos’ of the 50s and 60s were poor and guitar amps made to a budget. Some but not all technical principles of amp designs were well thought out. Fender and Marshall were the dominant and most copied brands. The powerful amps had 4 output valves in parallel push-pull and gave approx 60 - 100Watts.
The Myth Most amp manufacturers were conservative from a previous generation with a background of country, jazz and religious music. They were horrified by the anti-religious, drug driven, sex crazed rock musos of the 60s’ diving their amps at full power into hard distortion for sustain. When these amps were first designed in the 50s, it was inconceivable they would be used in this way.
The Reaction Many manufacturers reacted by making warranties void if amps were driven at full power, some threatened to cut off retailers who sold their amps to bands that played ‘music of the devil’. The parody of this historical contradiction has been rewritten, to fit mythical beliefs that brilliant designers created these amps for what ‘rock musos’ wanted.
Myths and Legends Valve technology is intrinsically the most elegant means by which a speaker is able to reproduce music. This is not because valves have magical qualities but because the technology by which they function is not achievable by other means. In ten thousand years from now Valve amplifiers will possible be the only remaining technology from the 20th century that will be still be being used and loved with as much passion as when first invented. As much as there is no proof that Valve amplifiers can sound superior to solid state I for one if given the choice will only listen to music through Valve amplification.
History Before solid-state technology, Valve amps were manually assembled by large teams of women in conditions that would not be accepted today. For domestic application the majority were not well made. Before manufacture, designs were scrutinised and modified to reduce production cost. Valve count kept to minimum, cheapest components used at voltage rating limits, safety standards almost non-existent.
The heart of a valve amplifier is the output transformer and accounts for most of the bulk and weight, it is also the most difficult and highest cost item to make. Size and therefore performance was reduced to minimum, especially when used for musical instruments. Only a few brands were made with technical excellence.
The arrival of the Solid State Amps By the mid 1960s, valve amp technology started to leap forward, but too late. As solid-state arrived, manufacturers competed to be first to make the change. This new technology reduced size and costs. It enabled production to be mechanised and staff reduced.
The first solid-state amps used germanium transistors, which performed poorly, until silicon arrived. The intense marketing of solid-state amps caused valve amps to be perceived as worthless, except for musicians. Virtually mountains of them ended up in the landfills of our expanding cities.
The Basic Principles A Valve is an extension of the light bulb. Theoretically inside the valve is a vacuum. The hot filament is called ‘Cathode’ (Let’s not forget a T.V. is a’ Cathode ray tube’ ). Around the outside of the Cathode is a cylindrical metal tube called ‘Anode’. When a +Voltage is placed on the Anode and a -Voltage placed on the Cathode, a large current can flow between them, but not the other way around.
This is called a ‘Rectifier’ or diode. Grid: A fine helix (spiral) wire called ‘Grid’ is placed between the Cathode and Anode. A small variable voltage (music signal) on the Grid varies the large current between the Anode and Cathode. The small varying input signal is now amplified to a large varying current. The result is very linear. Why this happens is a mystery. The fact that it works and the universe exists is a miracle. It pays to be humble. Transistors: (emitter base collector) are complementary to valves (cathode grid anode).
Transistors are related to crystals. Their individual function is non linear and have to be arranged in compound groups to behave as a linear circuit. Solid-state amps operate at low voltages (10 - 100V). Valves amps operate at high voltages (200 - 600V). Speakers operate at approx (0 - 40V). The Output Transformer converts the high operating voltages of valves to the lower operating voltage of speakers. A transformer has 2 separate coils of wire (primary and secondary) wound around an iron core. Electricity flowing through wire causes a magnetic field around the wire and visa versa, a changing magnetic field causes electricity to flow through wire.
The varying amplified current of the valve is connected through the first coil of wire (primary) and creates a varying magnetic field. The varying magnetic field created by the primary coil, causes electricity to be generated in the second coil of wire, which is wound tightly around the first. Electricity is transferred to the second coil only when the magnetic field is changing, not stationary. The iron core of the transformer keeps the magnetic field contained so little is lost. The transfer is very efficient. The secondary coil is connected directly to the speaker. The reduced secondary voltage is adjusted by the ratio of turns between the 2 coils. Eg 1,000 turns on the primary and 100 turns on the secondary would change the voltage 10:1. Most output transformers have a turn’s ratio of approx 20:1.
Why do Valve Amplifiers sound different? When technology changed from valve to solid-state, it was noticed that solid-state amplifiers lacked warmth and bass performance, and had to be twice as powerful as valve amplifiers, to sound as loud. Current Drive: Solid-state amplifiers behave in ‘Voltage Drive’. This acts as a short circuit (zero output impedance, or 100% damping factor) across the speakers, causing excessive damping, which reduces efficiency, limiting responsiveness. Valve amplifiers behave in ‘Current Drive’. This represents an open circuit across the speaker without over damping, allowing maximum response and efficiency.
Sensitivity: Valve amplifiers (current drive) are sensitive to crossover resonances and speaker impedance variations. Quality speaker systems often used passive crossovers that were second-order, constant impedance, and critically aligned to avoid resonant effects. Some quality speakers had copper caped pole pieces, which helped damp impedance variations. Note:- With solid-state amps in voltage drive, power decreases as the speaker impedance rises. With valve amps in current drive, power increases as the speaker impedance rises. Therefore a flat speaker impedance is synonymous with a flat frequency response.
Modulating Offset: The output of solid-state amplifiers is directly connected to 2 DC power supplies through the output transistors. The instantaneous non-symmetry within the music waveform (particularly from the bass notes) is averaged as a modulating DC offset. This modulating offset is small, but it varies the efficiency of the speaker, introducing inter-modulation distortion, amplitude modulating the music. This problem is mostly eliminated by the trend to use an active sub-bass. In valve amplifiers the output transformer isolates the speaker from the amplifier electronics. No modulating offset can be produced.
Open Loop Gain: Feedback Solid-state amplifiers are inherently nonlinear. They have a very large ‘open loop gain’ approx 20,000. The amplifier output is (feedback) to the comparator input to reduce the gain to approx 50. Therefore 99.9% of this feedback corrects all instability and non-non-linearity of the amplifier, as explained in amplifiers. The speaker also acts as a large microphone. All non-linear movements and vibrations within the speaker cone, (caused by reflected nodes, chaotic resonances etc) of which there are many, are regenerated back into electricity by the voice coil. This re-generated signal from the voice coil is inadvertanetly fed-back to the solid-state amps comparator input, and re-amplified back to the speaker as recycled distortion.
Re-amplified Distortion: This re-amplified distortion is audible by comparison, when switching between a solid-state and valve amplifier in real time. By paying close attention, it is heard as a fine spurious inter-cluttering within the music. This is clearly noticeable with efficient speakers but not with inefficient speakers. Valve amplifiers are inherently linear. Their natural gain is small and therefore require minimal or no negative feedback.
Their designs do not require them to have comparator inputs as with solid-state amps. The small amount of negative feedback in valve amps is only required to provide damping to the speaker. Valve Amplifier Design From physics we know certain things must be a particular order and size to be efficient and this is acutely so with valve amps. 60Watts is the minimum power capacity for an amplifier to bring quality speakers to life with full fidelity.
The reason: The dynamic range of music can exceed 60db (power ratio 1:1,000,000). Transients within the music can exceed 20db (power ratio 1:100). Therefore amps under 60Watts and ‘Single Ended Class A’ will not be discussed in this text. Valve amplifiers are used for applications such as guitar amplifiers, satellite transponders such as DirecTV and GPS systems, audiophile stereo amplifiers, military applications (such as target acquisition and radar) and very high power radio and UHF television transmitters.
- Tubeopedia - Wiki of electronic tubes and related topics
- The Vacuum Tube FAQ - Henry Pasternack’s FAQ from rec.audio
- The Audio Circuit - An almost complete list of manufacturers, DIY kits, materials and parts and ‘how they work’ sections on valve amplifiers
- Conversion calculator - distortion factor to distortion attenuation and THD
- AX84.com - Although oriented towards valve guitar amplifiers, AX84’s free schematics and theory document apply well to any tube/valve project