The Ibanez Tube Screamer is a guitar overdrive pedal

Effects unit

Effects units are electronic devices that alter how a musical instrument or other audio source sounds. Some effects subtly "color" a sound, while others transform it dramatically. Effects are used during live performances or in the studio, typically with electric guitar, keyboard and bass...

, made by Ibanez

Ibanez

is a Japanese guitar brand owned by Hoshino Gakki. Based in Nagoya, Aichi, Japan, Hoshino Gakki were one of the first Japanese musical instrument companies to gain a significant foothold in import guitar sales in the United States and Europe, as well as the first brand of guitars to mass produce...

. The pedal has a characteristic mid-boosted tone popular with blues players. The "legendary" Tube Screamer has been used by guitarists such as Stevie Ray Vaughan

Stevie Ray Vaughan

Stephen Ray "Stevie Ray" Vaughan was an American electric blues guitarist and singer. He was the younger brother of Jimmie Vaughan and frontman for Double Trouble, a band that included bassist Tommy Shannon and drummer Chris Layton. Born in Dallas, Vaughan moved to Austin at the age of 17 and...

 to create their signature sound, and is one of the most popular and most copied overdrive pedals.

Description

The pedal has an overdrive knob, a tone knob, and a level knob. The drive knob controls the level of distortion, the tone knob adjusts the amount of treble in the sound, and the level knob controls the output volume of the pedal. The pedal is used to try to mimic the sound of a vintage tube amp. The classic Tube Screamer sound includes a "mid-hump," which means that the circuit accentuates frequencies between the bass and treble ranges (mid-frequencies). Many guitarists prefer this sort of equalization, as it helps to keep their sound from getting lost in the overall mix of the band.

Variations

The pedal was produced with many variants. The early incarnations of the TS-808 (with and without hyphen) and TS9 are the most sought after by collectors. Other variants, including the TS10, TS7, and TS5 are less collectible and vary in their reproduction of the original circuit. The TS9 and TS-808 pedals have been reissued, and according to the company, feature the same circuitry, electronics and design components that helped shape the famous Tube Screamer sound. Some musicians have a technician perform modifications to the unit to change the sound to their liking. Also, Maxon

Maxon

Maxon may denote:* An electronic musical device Maxon Effects Pedals.A surname:* Bonnie Maxon American professional wrestler* William Ralph Maxon American botanist...

, who produced the original Tube Screamer pedals for the Ibanez brand in the seventies and eighties, produce their own version of the Tube Screamer. In addition, many of the most highly regarded overdrive pedals, both mass manufactured (e.g. BOSS SD-1) and boutique (e.g. Fulltone Fulldrive 2 MOSFET), owe their heritage to the Tube Screamer circuit.

Design

Mr. S. Tamura, the designer of the Tube Screamer, used a subtle clipping circuit to create the pedal's sound. He mixed the input signal with the output signal of the clipping circuit, which "preserves the original dynamics of the input signal which otherwise would get lost at the threshold of clipping." In this fashion, it preserves the "original dynamics of the input signal [and] avoids muddiness and vastly improves clarity and responsiveness." As well, Tamura added a post-clipping

Clipping (audio)

Clipping is a form of waveform distortion that occurs when an amplifier is overdriven and attempts to deliver an output voltage or current beyond its maximum capability...

 equalization

Equalization (audio)

Equalization is the process commonly used in sound recording and reproduction to alter the frequency response of an audio system using linear filters. Most hi-fi equipment uses relatively simple filters to make bass and treble adjustments. Graphic and parametric equalizers have much more...

 circuit with a first-order high-pass shelving filter

High-pass filter

A high-pass filter is a device that passes high frequencies and attenuates frequencies lower than its cutoff frequency. A high-pass filter is usually modeled as a linear time-invariant system...

 that "is linearly dependent on its gain," an approach called "progressivity." Characteristic of its clipping is the symmetrical nature.

The Tube Screamer uses electronic FET

Fet

Fet is a municipality in Akershus county, Norway. It is part of the Romerike traditional region. The administrative centre of the municipality is the village of Fetsund.Fet was established as a municipality on 1 January 1838...

 bypass switching. The circuit uses transistor

Transistor

A transistor is a semiconductor device used to amplify and switch electronic signals and power. It is composed of a semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current...

 buffer

Buffer amplifier

A buffer amplifier is one that provides electrical impedance transformation from one circuit to another...

s at both the input and the output. The overdrive is produced using a variable gain op-amp circuit with matched diode

Diode

In electronics, a diode is a type of two-terminal electronic component with a nonlinear current–voltage characteristic. A semiconductor diode, the most common type today, is a crystalline piece of semiconductor material connected to two electrical terminals...

s in the feedback circuit to produce soft, symmetrical clipping of the input waveform. The overdrive stage is followed by a simple low-pass filter

Low-pass filter

A low-pass filter is an electronic filter that passes low-frequency signals but attenuates signals with frequencies higher than the cutoff frequency. The actual amount of attenuation for each frequency varies from filter to filter. It is sometimes called a high-cut filter, or treble cut filter...

 and active tone control circuit and volume control. The TS7 allows switching between a "TS9" mode, in which the circuit and all relevant component values are identical to the vintage model, and a "Hot" mode, which introduces an additional gain stage.

Much has been made of the opamp

Operational amplifier

An operational amplifier is a DC-coupled high-gain electronic voltage amplifier with a differential input and, usually, a single-ended output...

 chips used in the various versions of the Tube Screamer pedal, and several articles have been written on the subject. The JRC4558D chip is particularly well regarded. In fact, the JRC4558D is used in Analog Man's "Silver" modification. Other popular chips included the TL072, RC4558P, and OPA2134. The TA75558, standard in the TS10 alongside the 4558, is regarded as the "ugly duckling of TS opamps."

Yet another variant is the Ibanez ST9 Super Tube that features a fourth knob ("Mid Boost"), which provides a harder attack.

Notable users

Used widely in genres as diverse as country, blues and shred, this stomper has been on more records, and used in more concerts, than perhaps any other overdrive or distortion pedal. The Tube Screamer has since spawned endless clones and modded versions.

External links

• The Technology of the Tube Screamer