Preamp, or gain, controls (sometimes called volume” on master volume-equipped amps) let you dial in impressive-sounding distortion at low volumes, but excessive preamp distortion can sound too compressed and sizzling at high volumes. A pre-amplifier is a low power amplifier that picks up a very faint electrical signal, boosting it enough for an audio power amplifier to then take it to the next level of amplification and send it on to the speakers. Key design parameters for audio power amplifiers are frequency response , gain , noise , and distortion These are interdependent; increasing gain often leads to undesirable increases in noise and distortion. Up-to-date pricing and reviews for Guitar Power Amplifiers on the market can be found at the power amplifier reviews website.
In the 2010s, there are still audio enthusiasts, musicians (particularly electric guitarists , electric bassists , Hammond organ players and Fender Rhodes electric piano players, among others), audio engineers and music producers who prefer tube-based amplifiers, and what is perceived as a “warmer” tube sound. Instead, the power attenuator’s attenuation control controls the power delivered to the speaker, and the amplifier’s master volume control determines the amount of power-tube distortion. Additionally, the basic sound produced by the guitar amplifier can be changed and shaped by adding distortion and/or equalization effect pedals before the amp’s input jack, in the effects loop just before the tube power amp, or after the power tubes.
Distortion sound or “texture” from guitar amplifiers is further shaped or processed through the frequency response and distortion factors in the microphones (their response, placement, and multi-microphone comb filtering effects), microphone preamps, mixer channel equalization, and compression. For electric guitar amplifiers, there is often vague a distinction between “practice” or “recording studio” guitar amps, with output power ratings of less than one watt to 20 watts, and “performance” or “stage” amps of 30 watts or higher. The FRFR approach assumes the tone is shaped by sound processors in the signal chain before the amplifier and speaker stage, so it strives to not add further coloration 20 or dedicated combo-style amplifiers with a broad frequency range.
Before widespread availability of modeling, guitarists did not commonly plug electric guitars straight into PA systems or powered speakers , because most genres relied on the tonal coloration of a regular guitar amplifier setup—from the preamplifier , equalization filters, power amp , guitar speakers , and cabinet design. Alternatively, a tube preamplifier can feed a solid-state output stage, as in models from Kustom , Hartke, SWR and Vox This approach dispenses with the need for an output transformer and easily achieves modern power levels. The preamplifier also changes the tone of the signal; high preamp settings add overdrive The power amplifier produces a high current signal to drive a loudspeaker and produce sound.
The first amplifier stage is a preamplifier It amplifies the audio signal to a level that can drive the power stage. Typically, guitar amplifiers have two amplifying circuit stages and in addition frequently have tone-shaping electric circuits, which usually include at least bass and treble controls, which function similarly to the equivalent controls on a home hi-fi system. Later, most guitar amps were provided with preamplifier distortion controls, and “fuzz boxes” and other effects units were engineered to safely and reliably produce these sounds.
The limited controls, the early loudspeakers , and the low amplifier power (typically 15 watts or less prior to the mid-1950s) gave poor high treble and bass output. These early amps had a “single volume control and one or two input jacks, field coil speakers” and thin wooden cabinets; remarkably, these early amps did not have tone controls or even an on-off switch. Guitar amplifiers can also modify the instrument’s tone by emphasizing or de-emphasizing certain frequencies, using equalizer controls, which function the same way as the bass and treble knobs on a home hi-fi stereo, and by adding electronic effects ; distortion (also called “overdrive”) and reverb are commonly available as built-in features.
There is a wide range of sizes and power ratings for guitar amplifiers, from small, lightweight “practice amplifiers” with a single 6″ speaker and a 10 watt amp to heavy combo amps with four 10” or four 12″ speakers and a powerful 100 watt amplifier, which are loud enough to use in a nightclub or bar performance. In a typical scenario such a power amp is used with a preamplifier and speaker cab and it is the preamp that is largely responsable for fundametally generating the clean and overdriven sounds, with the tube power amp adding warmth, dynamics, volume and the all important tube feel and response. Some of their uses include: providing a more authentic analog tone for recording, especially in today’s world of digital recording interfaces and DAWs; use as the heart of a direct rig for performance, where the traditional guitar amp is less than ideal because of size and/or volume constraints; as a means of fundamentally changing the tone of an amp by plugging into the amplifier’s effects loop return, thus by-passing the amp’s built in preamplifier; for use with a separate power amplifier and speaker cabinet (popular in the ‘80s and ‘90s but less so today).
Designed for use along with a guitar preamplifier, whether driving a speaker directly or when using the built in reactive dummy load, the Crucible adds power amplifier warmth, compression and overdrive, providing the missing link for the full tube amp experience. Most power amps are strictly for power, and thus have little, if any, tone controls on board, making them perfect blank canvases for players that use outboard preamplifiers and effects to achieve their tone. Designed to live in a rack stacked with preamps, power conditioners, and flashy looking effects processors, these utilitarian workhorses of the eighties rack era are typically devoid of the classy touches we normally like to see on our guitar amplifiers, from Tolex and decorative piping to fancy knobs and faceplates.
The MASTER KNOB was originally designed to simply control the input signal driving the power amplifier. While most audio amplifiers are designed to keep distortion as low as possible, guitar amplification has evolved to where overdrive distortion is usually a requirement. On the rear panel are two 1/4″ inputs and two pairs of 1/4″ outputs for Channels 1 and 2. The inputs may be switched from line level to instrument level, enabling you to plug a guitar or bass directly into the amp without a preamp.
The Mainline is a 300-watt solidstate stereo power amplifier designed to emulate the sound and feel of a tube guitar amp. With XLR and 6.35 mm inputs as well as Speakon compatible and 6.35 mm output connectors the Palmer MACHT 402 is the ideal power station for guitar preamps, small amps, modelers and even effects pedals. Conventionally named, the channels’ Hi and Low controls have been carefully tailored for guitar signals to provide extensive EQ facility, a wide variety of sounds and authentic tube power stage characteristics.
- Solid-state amp with tube simulation – One input and 2 speaker outputs per channel – 2×150 watts max stereo or 300 watts max mono – One volume and one reactance (tube simulation) control per channel – Bridged mode button (mono or stereo) UTILI… Microphone preamplifiers are generally designed to expect balanced audio, and are built with differential amplifiers to ensure the balanced audio signal is properly received. When dealing with any kind of audio signals, amplification is often a necessary step between devices (microphones to mixers, mixers to loud speakers, etc.). Amplifiers, as the name suggests, are needed to provide such amplification to the audio signals.
I did enjoy having preamp gain set to a c.c. footpedal and all of the effects’ quality still ranks up there pretty high.. I am looking for some DEDICATED guitar tube power amplifier plans and layouts, between 30w and 50w I´d like to build my own… During development of the Roland Blues Cube series of guitar amplifiers, our designers painstakingly identified the complex interactions between every single component inside the power amp section of a vintage, all-tube, tweed amplifier. At lower volumes, solid-state guitar amplifiers maintain sounds also reached at much louder levels.
Through tone shaping, generating overdrive and adding effects, the preamp is one of the key factors of what makes guitar amplifiers sound different each another. The preamp does this is by passing the input signal through circuitry called gain stages, usually at least 2. The main component of a gain stage is an active electronic component, either a vacuum tube or a transistor. At the most fundamental level, every guitar amplifier features a preamp, power amp and speaker.
Guitar amplifiers built with the preamp, power amp and speaker all in the same wooden box are called combo amplifiers. Almost all of the controls on the front panel of the guitar amp (gain, bass, mid, treble, volume etc.) are controlling the circuitry within the preamp. Everything from the preamp to the power amp, number and type of gain stages, speaker, output transformer, and where the EQ sits in the circuit path all play their part.
Widely known as the man who started VHT Amplification in the late 1980s, he was responsible for one of the first 3-channel tube guitar amplifiers, the aggressive Pitbull line of amps, and a pair of incredibly popular all-tube, rack-based power amplifiers. The tube preamp reacts with a guitar the same way any tube amplifier does: it generates harmonics and the sweet sounding high fidelity tone that tubes are known for. The STEALTH is based on analog class A/B amplifier design for excellent sonic and saturated clipping performance, not found with Class D power amplifiers and will exceed the stringent tone characteristics of the professional guitarist.
2-Channel USB-C Audio Interface 24-Bit/192 kHz AKM converters, Mic preamps (62 dB gain range, 130.5 dBu ON), Neutrik connectors, Alps pots, Legacy “4K” switch per channel for sounds inspired by the legendary SSL 4000 series, +48 V Phantom power,… • 6L6—Used in classic American stage amps and some modern high-gain designs, the 6L6 output tube delivers high-headroom punch with a round and full midrange character. A key feature is Character Shape, which unlocks designer-level sound control right at the heart of the power amplifiImportant applications include public address systems, theatrical and concert sound reinforcement systems , and domestic systems such as a stereo or home-theatre system Instrument amplifiers including guitar amplifiers and electric keyboard amplifiers also use audio power amplifiers. For example, a Class B amplifier will probably have just the high power output devices operating cut off for half of each cycle, while the other devices (such as differential amplifier, voltage amplifier and possibly even driver transistors) operate in Class A. In a transformerless output stage , the devices are essentially in series with the power supply and output load (such as a loudspeaker), possibly via some large capacitor and/or small resistances. For this reason, the design choices made around the output device (for single-ended output stages, such as in single-ended triode amplifiers) or devices (for push-pull output stages), such as the Class of operation of the output devices is often taken as the description of the whole power amplifier.
The final stage of amplification, after preamplifiers, is the output stage, where the highest demands are placed on the transistors or tubes. Some electric guitar amps have three controls in the volume section: pre-amplifier, distortion and master control. The simplest guitar amplifiers, such as some vintage amps and modern practice amps, have only a single volume control.
In a standard master-volume guitar amp, as the amp’s final or master volume is increased beyond the full power of the amplifier, power tube distortion is produced. Because many factors beyond preamp distortion contribute to a particular guitarist’s sound, recording engineers and PA system techs typically put a microphone in front of the guitar speaker, rather than only use the guitar amp’s pre-amp out signal. These have been fixed-power amplifiers, jargon with some models having a half-power switch to slightly reduce the listening volume while preserving power-tube distortion.
There are many varieties of speaker combinations used in guitar speaker cabinets, including one 12″ speaker, one 15″ speaker (this is more common for bass amplifiers than for electric guitar cabinets), two 10″ speakers, four 10″ speakers, four 12″ speakers, or eight 10″ speakers. Players can get a reasonable facsimile of the sound of tube amplifiers, vintage combo amplifiers, and huge 8×10” speaker stacks without bringing all that heavy equipment to the studio or stage. 18 19 Modeling amplifiers and stompbox pedals, rackmount units, and software that models specific amplifiers, speakers cabinets, and microphones can provide a large number of sounds and tones.
Only a few solid-state amps have enduring attraction, such as the Roland Jazz Chorus 15 16 17 Solid-state amplifiers vary in output power, functionality, size, price, and sound quality in a wide range, from practice amplifiers to combos suitable for gigging to professional models intended for session musicians who do studio recording work. Guitar amps that include a mic input are in effect small, portable PA systems Some amps, typically bass amps, have an XLR connector to provide a balanced output from the preamp section to a PA system or recording input. More expensive amps may have a number of knobs that control pre-amp volume (or “gain”), distortion or overdrive, volume, bass, mid and treble, and reverb.
Tone stages may also provide electronic effects—such as equalization , compression, distortion, chorus , or reverb Amplifiers may use vacuum tubes (called valves in Britain), solid-state (transistor) devices, or both. In the first case, the clipped signal is applied directly to the amp’s input, and in the second it is attenuated to exactly half voltage (one quarter power – nominally 25W) with the master volume control. The Two/Ninety/Two Stereo Power Amp has proven itself to be the standard for tube power performance not only in its own size and class, but against many power amplifiers boasting considerably higher output power. Be sure to visit power amplifier reviews for the best Guitar Power Amplifiers on the market to buy.
While single ended amps have their own unique response and can sound great in their own right, a push-pull design is essential for nearly all of the classic overdriven tube power amp tones we have become accustomed to on our favorite rock and blues recordings.