The Fender Bandmaster was a musical instrument

amplifier An amplifier, electronic amplifier or (informally) amp is an electronic device that can increase the magnitude of a signal (a time-varying voltage or current). It may increase the power significantly, or its main effect may be to boost the v ...

made by Fender. It was introduced in 1953 and discontinued in 1974.Teagle, J. and Sprung, J.: Fender Amps: The First Fifty Years Some early models had both a

microphone A microphone, colloquially called a mic or mike (), is a transducer that converts sound into an electrical signal. Microphones are used in many applications such as telephones, hearing aids, public address systems for concert halls and public ...

input and instrument inputs. Beginning in 1960, Bandmaster amps were equipped with a

vibrato Vibrato (Italian language, Italian, from past participle of "wikt:vibrare, vibrare", to vibrate) is a musical effect consisting of a regular, pulsating change of pitch (music), pitch. It is used to add expression to vocal and instrumental music. ...

effect Effect may refer to: * A result or change of something ** List of effects ** Cause and effect, an idiom describing causality Pharmacy and pharmacology * Drug effect, a change resulting from the administration of a drug ** Therapeutic effect, a ...

. In the 2000s, vintage Bandmaster amps remain in use by

blues Blues is a music genre and musical form which originated in the Deep South of the United States around the 1860s. Blues incorporated spirituals, work songs, field hollers, shouts, chants, and rhymed simple narrative ballads from the Afr ...

Americana Americana may refer to: *Americana (music), a genre or style of American music *Americana (culture), artifacts of the culture of the United States Film, radio and television * ''Americana'' (1992 TV series), a documentary series presented by J ...

and

rock and roll Rock and roll (often written as rock & roll, rock 'n' roll, or rock 'n roll) is a Genre (music), genre of popular music that evolved in the United States during the late 1940s and early 1950s. It Origins of rock and roll, originated from Africa ...

bands. File:1968_Fender_Bandmaster_front.jpg , Fender Bandmaster, silverface, 1968 "drip-edge" with AB763 circuit File:1968_Fender_Bandmaster_back.jpg , (back)

Timeline

''Timeline gleaned from''

Cosmetics

Tweed Tweed is a rough, woollen fabric, of a soft, open, flexible texture, resembling cheviot or homespun, but more closely woven. It is usually woven with a plain weave, twill or herringbone structure. Colour effects in the yarn may be obtained ...

Blonde Blond (male) or blonde (female), also referred to as fair hair, is a hair color characterized by low levels of the dark pigment eumelanin. The resultant visible hue depends on various factors, but always has some yellowish color. The color can ...

Blackface Blackface is a form of theatrical makeup used predominantly by non-Black people to portray a caricature of a Black person. In the United States, the practice became common during the 19th century and contributed to the spread of racial stereo ...

Silverface Fender amplifiers are a series of electric instrument amplifiers produced by the Fender Musical Instruments Corporation. The first guitar amplifiers attributed to Leo Fender were manufactured by the K&F Manufacturing Corporation (K&F) betwee ...

1967–1974 ** Drip Edge 1967–1968 ** Black Line 1967–

Circuit notes

5C7

The first Bandmaster was in all respects almost identical to the Fender Pro, a dual-6L6 26-watt amp with a 1x15 speaker, with one difference: separate treble and bass controls, where the Pro like all other Fender amps to that time only had a single "Tone" knob. Like the other larger Fender amps, the Bandmaster used cathode-biased 6L6G output tubes, a 6SC7 paraphase inverter, and two more 6SC7s in the preamp with a 5U4 rectifier.

5D7

The D-series circuits represented Fender's shift from octal preamp tubes, e.g. the 6SC7, to nine-pin mini-tubes of the 12A(n)7 family, as well as the introduction of the floating-paraphase inverter.

5E7

Negative feedback and filter choke added, and the output section given fixed (grid) rather than cathode bias. Phase inverter changed to cathodyne (concertina) type.

6G7 and 6G7-A

The 6G(n) ("brownface") circuit was used in several Fender amplifiers, including the Bandmaster. It produces 40 watts into 4 ohms. The circuit was used from 1960 until July 1963 when the "AB763" circuit was introduced. "Blonde" aficionados feel this circuit has superior tonal characteristics when overdriven, to the AB763 circuit. The 6G7 and revised 7-A circuit used the long-tail pair phase inverter introduced with the 1957 Bassman, used a solid-state rather than a tube rectifier, and also included a vibrato that is heralded as Fender's best by many enthusiasts. Power tubes were now 5881s (6L6WGBs).schema electrique pour un fender ban master 1961 The new model was covered in Tolex rather than "tweed;" still a combo in brown Tolex for 1960, and then a blonde-covered head-and-cab piggyback 1961-63.

AA/AB763

The AA763 (July 1963) and improved AB763 (March 1964) ("blackface") circuit is arguably considered the "best" circuit version produced for this amp by collectors and aficionados. The complex brownface "harmonic vibrato", however, was replaced by a simpler electro-optic oscillator. Power tubes were the even beefier 6L6GC. Some 1964 blackface Showmen were still covered in blonde Tolex rather than the usual black. Later "silverface" amps retrofitted to this circuitry are described as having been "blackfaced," a reference to the black faceplate used on these amps during much of this era.

AA568

The AA568 version (introduced May, 1968) was met with popular dislike by Fender's customers. It is referred to at times as the "

silverface Fender amplifiers are a series of electric instrument amplifiers produced by the Fender Musical Instruments Corporation. The first guitar amplifiers attributed to Leo Fender were manufactured by the K&F Manufacturing Corporation (K&F) betwee ...

" circuit, referring to the brushed aluminum control plate used from 1968 to 1974. The circuit and cosmetic changes didn't happen at the same time; some 1967 and early 1968 Bandmasters still possessed the

blackface Blackface is a form of theatrical makeup used predominantly by non-Black people to portray a caricature of a Black person. In the United States, the practice became common during the 19th century and contributed to the spread of racial stereo ...

AB763 circuitry. Unfortunately, the tube chart inside the amp head cannot be reliably used to differentiate the AB763 from the later circuits, as Fender continued using the older tube charts for a while after changing the circuit configuration.

AA1069

Some of the changes from the AA568 were reverted in October, 1969, yielding the AA1069 circuit, but many of the changes remained in place.

References

{{Fender Instrument amplifiers B Musical instruments invented in the 1950s