How Fender's invention of the Precision Bass led to one of its greatest amps.
By Jeff Owens
Consider a challenge posed by Leo Fender’s 1950-1951 development of the world’s first commercially successful solid-body electric bass guitar, the Precision Bass. Since the solid-body electric bass guitar was largely a previously nonexistent form of instrument, what was it supposed to be plugged in to? There were no suitably powerful and reliable amps in 1951 made specifically for bass guitar, because there weren’t any bass guitars.
Consequently, when it first appeared in music stores in November of that year, the revolutionary new Precision Bass was paired with Fender’s TV-front 1×15” Pro guitar amp.
Leo Fender and his staff were building a new TV-front 1×15” amp designed specifically for use with the Precision Bass, but it wasn’t ready until 1952, when it appeared in Fender’s sales literature labeled simply as “Amplifier.” Very soon though, Fender sales chief Don Randall gave it a thankfully less-generic name: the Bassman (Randall named all Fender amps of the era and all the instruments except the Precision Bass, a name coined by Leo himself).
The original Fender TV-front Bassman of 1952 was a bare-bones amp with two knobs (volume and tone) and two instrument inputs on a top-mounted control panel, a bottom-mounted copper-plated steel chassis and what Fender billed as a “specially designed” Jensen P15N speaker. It was the first Fender amp with a closed back; this had two large round ports and was specifically designed to enhance bass response (the 1×15” Pro that accompanied the first Precision basses was open-backed, like all other Fender guitar amps at the time).
The original Bassman was solid, powerful and loud. Guitar expert George Gruhn, quoted in noted guitar historian/author Tom Wheeler’s The Soul of Tone: Celebrating 60 Years of Fender Amps, notes that with its advent, Leo Fender “made the first amp that was worth calling a bass amp.”
As is so often the case with Fender amps in the first decades of the company’s existence, evolution proceeded rapidly. Fender was phasing out the TV-front style by summer 1952 in favor of the wide-panel design, and the Bassman was no exception. Restyled with a wide-panel front, the 1953 version (model 5B6) was otherwise essentially the same amp as its TV-front predecessor. At that time, Fender still touted it as a bass-only amp—“It is not a hashed-over guitar amplifier, but an instrument that has been designed for the reproduction of bass and bass only,” the catalog read.
A growing number of musicians, however, were finding that the Bassman made a fine guitar and harmonica amp, too. Fender heeded this and soon stopped billing the amp as a bass-only model. And if guitarists were impressed by the tone and power of the short-lived wide-panel 5B6 model of 1953-1955, they were about to have their minds blown by the amp’s next iteration.
To replace the wide-panel style, Fender started building its “narrow-panel” tweed cabinets, which featured less cabinet and more grille in front, in late 1954 for the 1955 model year. In the meantime, back in Fullerton, Calif., Leo Fender and his staff were hearing complaints that model 5B6 couldn’t sufficiently handle low frequencies and that its single 15” speaker tended to blow.
Fender responded in fall 1954 with a redesigned version of the amp, the narrow-panel model 5D6—the first 4×10” Bassman. It pumped 40 watts through four 10” blue Jensen P10-R speakers. It still had only two inputs, “normal” and “bright,” indicating that Fender was well aware that the amp was being used by guitar players, too. Indeed, the amp appeared in the February 1955 price list with the notation that “While its characteristics have been designed to accommodate string bass, at the same time it makes an excellent amplifier for use with other musical instruments.”
The new narrow-panel version of 1955 also featured more controls—bass, treble and presence knobs, plus standby and ground switches—that were a significant tonal improvement over the sparse control layout of the earlier TV-front and wide-panel versions.
Listing the original 4×10” Bassman’s features, however, doesn’t really convey what a landmark in the history of instrument amplification it really was. In The Soul of Tone, Wheeler writes that:
For starters, it’s powerful, it’s loud, and it’s sensitive to the player’s touch. It sounds great, responding beautifully across the frequency spectrum. It exhibits a sparkling, harmonically rich tone at low and moderate volumes. At louder volumes it thickens with a sweet distortion that only seems to get creamier the more it’s cranked. It is particularly well matched to certain popular guitars, especially the Stratocaster.
The narrow-panel tweed 4×10” Bassman went through several periodic variations in circuitry over its five years in production, starting with model 5D6 in fall 1954, continuing through model 5D6-A (1955) and model 5E6 (1956), and culminating in model 5F6 (1957) and in what many consider to be one of the greatest guitar amplifiers of all time, model 5F6-A (1958-1960).
What is it about model 5F6-A—the last in the original tweed Bassman series—that has made it such a prized and copied amp? It and its immediate predecessor, model 5F6, had an added midrange control and four inputs (high gain/low gain “normal” and high gain/low gain “bright”). Certainly it was powerful—four 10” speakers move a lot of air, and a 1959 model could definitely fill a room with its upgraded Jensen P10Q speakers. Once again, perhaps Wheeler put it best in The Soul of Tone when he noted that:
It seems to combine the perfect array of preamp components, output tubes, power, negative feedback loop, passive tone controls, cab, baffle, and speakers.
It was the circuitry of this amp that was copied in London in 1962 by Jim Marshall and Ken Bran as the basis for the first Marshall guitar amplifiers.
The tweed era ended with the 1950s, however, and model 5F6-A was discontinued in 1960 when most Fender amps changed from tweed to a textured vinyl covering called Tolex.
The 1960s was a decade of constant change for the Bassman. Narrow-panel tweed model 5F6-A was succeeded in 1960 by a completely different version, model 6G6, which was a 1×12” piggyback model in blonde Tolex with maroon grille cloth, front-mounted brown control panel and brown handle. Gone were the black “chickenhead” knobs of the ’50s, replaced by cylindrical white knobs. This was succeeded in short order by 2×12” model 6G6-A. Wheat-colored grille cloth replaced maroon in late 1962, and a reinforced black handle replaced the brown handle (which tended to break) in early 1963.
The next iteration of the 2×12” Bassman appeared in mid-1963, with a numbered black (“blackface”) control panel, white cylindrical knobs, smooth white Tolex covering, gold sparkle grille cloth and a raised Fender logo (with tail)—a sharp but short-lived look. By mid-1964, it had black Tolex covering and silver sparkle grille cloth; the first of these still had white knobs, but these were very quickly replaced by black knobs that were both numbered and skirted. This model (AA864) had substantially different circuitry than its predecessors—the “presence” control was removed, and “bright” and “deep” switches were added.
The blackface Bassman with black Tolex covering and black knobs existed basically unchanged until 1967. This was a period that encompassed Fender’s 1965 sale to CBS and the summer 1966 start of Fender’s ill-fated experiment with solid-state electronics. This included a transistorized version of the Bassman—a 105-watt piggyback beast with three 12” speakers and a four-position “Style” switch. Odd, but it lasted until 1971, when Fender discontinued all solid-state amps.
Fender continued to build tube amps while it conducted its solid-state experiment, however, and the 1968 catalog showed yet another tube Bassman variation, this time with a gigantic speaker cabinet that, while 75 percent larger than the previous enclosure, still only housed two 12” speakers.
That year also saw the introduction of the “silverface” amps, which included another new Bassman; its circuitry was the same as the final blackface versions. In fall 1968, the 2×12” configuration was replaced by two 15” speakers in the same-sized cabinet. The amp’s aluminum trim was discarded in mid-1969, resulting in a silverface style that would exist basically unchanged into the 1980s.
Also in 1969, Fender introduced its first truly big bass amps, the 100-watt Super Bassman I and Super Bassman II. These were Fender’s most expensive amps at the time, with a head and cabinets that were all physically larger than their predecessors. The Super Bassman I had a single 2×15” cabinet while the Super Bassman II had two; both used the same head.
The regular 50-watt model remained available during the short (1969-1971) tenure of the Super Bassman. This model became the 2×15” Bassman 50 in 1972, a year that also saw the arrival of the 50-watt Bassman 10 combo (the first 4×10” version in more than a decade, although it had a sealed back) and the 100-watt piggyback Bassman 100, which was basically a Super Bassman repackaged with four 12” speakers.
Names were changed with upgrades in power in 1977—the 50 became the 70 and the 100 became the 135. Solid-state returned in 1981 with the small 1×15” Bassman Compact, and one more small tube model, the 1×15” Bassman 20, appeared in 1982 before all Bassman amps were discontinued in 1983 with the impending end of the CBS era.
The new Fender corporation resurrected the name in 1988 with the introduction of the third solid-state series; this included the 60-watt 1×15” Bassman.
Once Fender’s gradual resurgence gathered real steam throughout the latter 1980s, the company turned its attention to its roots in the 1990s with a series of acclaimed and highly successful reissue tube guitar amps. These were based on classics of the 1950s and ’60s, and first among them was the ’59 Bassman, released in 1990 and based on model 5F6-A. This was succeeded in 2004 by the Vintage Reissue series ’59 Bassman LTD, which has a lacquered tweed covering and four 10” Jensen speakers instead of the Eminence speakers used in the earlier reissue.
Concurrently during its modern era, Fender also marketed a line of bass heads and combo amps under the Bassman name, although these bore little or no connection to the Bassman amps of the 1950s, 1960s and 1970s and were “Bassman” products in name only.
The model came full circle in a way in 2009 with the introduction of the four Bassman TV series amps, specifically designed for bass guitar in 1×10”, 1×12”, 1×15” and 2×10” versions. These tweed-covered TV-front amps are highly evocative of but not strictly copied from the very first 1×15” Bassman model of 1952.
In 2015 Fender introduced the dual-channel Bassman 500, combining Fender’s world-standard "blackface" tube preamp with a lightweight 500 watt Class D power amp and a wealth of innovative features on the front and rear panels.
Fender released the Bassman 800 bass amp head. This versatile, portable and powerful addition to the Bassman family offers two versatile channels (vintage and overdrive), classic good looks, and ultra-musical Fender tube tones—all in a lightweight chassis (only 17 lbs.) that mates perfectly with Bassman Pro Neo speaker cabinets to create a tonal monster.