A bass guitar amplifier head is the component that creates the amplifier’s sound, and can be sold separately from cabinets for use with different styles of sounds.
Your bass amplifier could come equipped with an equalization control that offers wide tonal variations and allows for tonal customization to meet the requirements of any venue. These options may help shape your tone to meet these specifications.
Preamp
Preamp sections of bass amp heads house controls and features that help shape your sound, such as gain and master volume controls, to help achieve the ideal amount of amplification and tone you are after. Some amps may also feature built-in overdrive channels that offer everything from subtle warmth to heavy distortion distortion; amps like the Ampeg SVT400-PRO even feature an effects loop which lets you plug an external pedal directly into its return connection for a completely unique tone!
An audio crossover is another key component of a bass amp head. It allows for separation of bass signal into low and mid frequencies to go to specific cabinets (e.g. 1×15 cabinet) while high frequencies go to 2×10 cabinets equipped with horn-loaded tweeters for full range frequencies. Some amps may allow users to customize this frequency; other models might set this at predetermined levels so you can tailor its sound according to whatever song is currently playing.
Not only are bass amplifier heads equipped with standard preamps, but many also contain features that will prove beneficial to bassists such as DI output. This allows you to use your amp as power amp without needing a separate cabinet and speaker setup, which is often useful during live situations. Some bass amps even come equipped with built-in metronomes or tuners which make for convenient practice sessions at home.
Hybrid bass amplifier heads combine a tube preamp with a solid state power amp for maximum tone with minimal maintenance requirements and less fragility than traditional tube amps. Some hybrid amps even include an emergency bypass switch to switch over in case there are technical difficulties with either of the tubes.
EQ
Bass amplifiers differ from their electric guitar counterparts in that they must reproduce low frequencies more faithfully, often calling for smaller speakers and larger cabinet sizes than what’s used for other instruments. As a result, these amps often include crossover circuitry to separate out low and middle frequency signals from one another and route them separately to drivers on speaker cones. Their primary feature, though, remains their power amplifier: either tube- or solid state powered; some bass amps even include both technologies in hybrid circuits that combine preamp with solid state amp technologies or combinations using both technologies simultaneously.
Bass amp heads typically include input and output jacks that allow users to connect other equipment, such as power cords, speaker cabinets or effects pedals. Higher-cost amps designed for professional use may have Direct Injection (DI) output jacks that enable bass signals to be sent directly into mixing boards or PA systems without losing much gain or equalization; some DI output jacks even feature switches so sound engineers can adjust volume levels independently of amplifier and equalization settings.
Modern bass amps often include a graphic equalizer, which offers users control over different frequency bands by moving vertical sliders. This gives bassists more control over their tone, and is especially beneficial when performing live gigs as it allows them to tailor the amplifier response to suit its environment’s acoustics.
Some amplifiers feature an inbuilt overdrive effect that ranges from subtle warmth to heavy distortion, and is used both on its own or combined with clean channel. To activate it, use a footswitch or increase gain until gain knob reaches high setting; bassists may have various settings available such as blend controls for more custom settings of overdrive effect.
Crossover
A bass guitar amp head works by amplifying low voltage audio signals into higher ones that drive speaker cones. The power amplifier section may either remain acoustically transparent – keeping the original bass sound unaltered – or add its own distinct tone (also referred to as being “scooped”). Rock bassists who prefer their amps with distinct sounds often prefer this latter type of amplifier.
A bass guitar amplifier head typically contains multiple input and output jacks for connecting various instruments and accessories. For instance, there may be a 1/4″ input for piezoelectric pickups as well as an XLR input to receive audio from condenser microphones mounted in bass cabinets. There may also be a line out jack that allows bassists to send line-level signals directly out through this connection to external devices like mixing boards or powered speaker cabinets; they can control how active this feature is using controls located on their amp.
Many bass amplifier heads feature an overdrive section that enables players to create overdriven tones ranging from mild warmth to severe distortion, like Lemmy Kilmister of Motorhead who used a triple 100W Marshall bass combo with tube preamps in order to get his iconic fuzz bass sound.
Bassists who wish to record with their amp heads require one with enough power output to drive studio monitors and headphones, along with preamp controls (master volume control, preamp gain controls etc) as well as one or more EQ controls (bass and treble) that allow for tone shaping. Such an amp may come equipped with master volume and preamp controls with master volume as well as bass/treble controls that help shape tone shaping.
Modern bass amp models often include additional features for live performances that can assist bassists. Most models provide a graphic equalizer, which can help fine-tune sound. Some even come equipped with vertical sliders to control different frequency bands.
Bassists can choose to purchase either an amp head alone or as part of a bass stack, where both cabinets house the bass amp head atop. A full stack consists of two cabinets with the bass amp head on top while half stacks only require one cabinet and amp head; when purchasing as part of a stack, bassists should experiment with various speaker cabinets until finding one they prefer best; it is always important that their cabinet and amp head match in terms of power output and impedance rating to avoid damaging their speakers with excessive power overloaded amp heads being powered too much power can damage speakers that need protection against overpowering their amp heads resulting in amp heads being overdriven resulting in damage that damages speakers due to overpowering their speakers!
Power
A bass amp head’s power section determines its overall volume. Higher-wattage amps produce higher sound pressure level (SPL), making them ideal for large venues where bassists must fill out every space available to them with sound.
Many bassists prefer hybrid power amp heads which combine both tube and solid state amplifier technology. A tube preamp provides classic tones and tonality of a tube amp while the solid state power amplifier pushes speakers past normal loudness levels without clipping. Solid state amps tend to be lighter and cheaper.
Professional bass amps often come equipped with built-in crossover filters that divide the signal into low, medium and high pitched frequencies for easier routing by the bassist. Low frequencies should go to cabinets tailored towards low sounds while middle and high frequency signals should go into cabinets designed specifically to handle them.
As well as seeking an amp with EQ controls, bassists will typically look for one with various inputs and outputs that meet their gigging or recording setup needs. For example, those using pedal effects would likely benefit from having one equipped with loop input/output connectivity for easy pedal integration.
Some basses require an amplifier equipped with a dedicated DI out jack to allow a bassist to directly connect their amp to a mixing board. Professional-grade amps equipped with DI out features typically also come equipped with additional useful features for recording professionals, such as a “ground lift” switch to prevent ground loops, and pre/post switches that determine whether signal goes to PA or mixing board prior or post internal preamp and equalization circuitry; plus an adjustable control knob which determines how much compression takes place as signal passes through preamp. Small combo amps like the Fender Rumble 100 and Ampeg PF-350 Portaflex provide bassists with all of these features in a portable unit that’s easy to transport, while larger combos such as Ampeg SVT-8-PRO and Mesa/Boogie Dual Rectifier provide them in more modular designs that allow users to combine features according to their individual bassist needs.