By jumping the bass and normal channels on a black-panel Fender Bassman and applying some simple settings tweaks, you can achieve vintage-bass-tone bliss.
Learn how classic Fender amplifiers can be tweaked and retrofitted to give you smooth, vintage bass tones.
Those of you who have read my earlier columns know I am a diehard fan of the classic Fender tube amps, particularly the black- and silver-panel-era Fenders. They’re great tone platforms that can take you in many directions with various guitars and pedals, and they work just as well for harmonica, electric piano, and bass guitar due to their natural, straightforward tone. In this column, I’ll share my experiences and tips for running a bass through different Fender guitar amps.
Guitar amps and speaker cabinets are normally built much lighter than typical closed bass-amp cabinets. High-wattage bass amps require dense, robust construction that can handle serious air pressure. They’re often closed cabinets with air intakes called bass reflex systems, which control airflow from the speaker vibration and enhance the lower frequencies. But even without a bass reflex system, some guitar amps can produce a nice bass-guitar tone. Obviously, they’re not capable of doing what an 8x10 Ampeg cabinet can do, but for me, that’s not relevant. The music that I listen to and play (mostly ’60s and ’70s rock, soul, and blues) has a laid-back yet articulate bass tone.
I grew up listening to a lot of Donald “Duck” Dunn’s Jazz and Precision bass-guitar playing on recordings by Otis Redding, Booker T. & the M.G.’s, and other legendary artists from Stax records in the ’60s. For Dunn’s tone—which drives the groove and forms a significant part of the mix—you don’t need an extremely deep or punchy bass. With classic Fender guitar amps, you can get a mellow bass tone with medium-low frequencies that blend in smoothly with a band.
Fittingly, the first amp I’d like to mention is the Fender Bassman. The black-panel version—a 50-watt head with a diode rectifier, negative feedback loop, and dual 6L6 tubes—shouts “clean headroom.” The 2x12 speakers in the matching, closed piggy-back cabinet sound bassy and tight, and offer more low end than any of the open-back Fender amps. The amp has two channels, one voiced for bass and one for guitar. The bass channel offers a deep switch to better tune in or out the lowest frequencies, and you can unlock more tone options by installing a 25k mid switch in the normal channel, a mod I explain in my May 2023 column, “Why Did I Ever Sell These Amps?” The mid switch acts like a fat boost that can trigger the amp to distort if you play at the threshold of the amp’s breakup point.“With classic Fender guitar amps, you can get a mellow bass tone with medium-low frequencies that blend in smoothly with a band.”
Another trick I like to do is jump channels. I dial in a full, relaxed tone on the bass channel, and a brighter tone on the normal channel with the bright switch on. (Sometimes I add some overdriven tones using the mid switch and volume on the normal channel.) If you’re after more volume, consider installing louder, more efficient speakers. The original Oxford, Jensen, or Utah speakers in vintage Fender amps are modest compared to modern ceramic or Neodymium speakers, which can help lighten the heavy speaker cabinet. Plus, you can use other external speaker cabinets with the 4-ohm Bassman head for more punch and different tones. The speaker impedance should be between 2 and 8 ohms, but 4 ohms will give you the most clean headroom.
The Fender Showman and Dual Showman are two other piggy-back amps worth mentioning. Compared to the Bassman, these models have some advantages. They boast almost twice the power for bigger stages and rooms, and the Dual Showman’s flexible impedance allows you to use a variety of speaker cabinets. (I prefer 10" and 12" speakers over the original 15" Showman ones for their faster response and lighter weight.) That said, they lack the Bassman’s deep switch, dedicated bass channel, and ability to jump channels.
Finally, we have the Tweed Bassman and the Super Reverb. By specs alone, the black-panel Super Reverb is the heir of the narrow-panel Tweed Bassman. Both have open-back 4x10 cabinets and a 40-watt, dual 6L6 power amp section in push/pull configuration. With four 10" speakers working together, the cabinet doesn’t necessarily need to be enclosed to achieve a nice bass tone. These amps will work well for bass guitar in practice and in smaller settings, but be careful with older 10" speakers. The dry, porous paper speaker cone and thin copper wires can easily be damaged at higher volumes, so for bass usage, I’d recommend replacing them with newer speakers. Since I use my amps for both guitar and bass, I like regular guitar-voiced speakers, but if you’re using the amp exclusively for bass, you might consider using bass-specific speakers.Conventional wisdom says that, as a string anchor point, the metal alloy must play a tonal factor. But it's more complicated than that....
There is a lot of discussion about the dimensions of frets and their influence on playing, especially among guitarists. Sure, bassists tend to use bigger frets, but, other than that, we seem to care far less about dimensions and more about their tonal influence.
In conversations about tone, some might immediately disregard the influence of frets due to their comparatively small size and get back to talking about woods some more. One reader recently questioned whether frets have any notable influence on tone. The question is absolutely legit, since frets are very prominently positioned at one of the anchor points of our strings. They are not going to have a dominating impact on our tone, but those claiming they have no impact probably also question the endless discussions about nut and bridge materials, too.
Materials that have been used for frets range from wood to different types of brass, Delrin, stainless steel, and the classic, standard nickel-silver. Wood, obviously, and Delrin, which is a trademarked name of a polymer/thermoplastic material, aren't commonly used nowadays. However, it's possible Delrin has a brighter—or darker—future once people learn it's the only way to get black frets.
The term “brass" can be a bit confusing, since it comes in a lot of flavors. It's mainly a mix of copper and zinc, but, as is often the case with alloys, smaller portions of additional metals like tin, lead, and nickel have huge influences on the physical properties of brass. Nickel silver (aka German silver) is, in fact, another brass variant and is also known as nickel brass. There is the euphonious term “bell brass," which is actually bronze (not real brass), due to its higher amount of copper. To add to the confusion, the word “bell" is also often used to distinguish between casted and extruded materials, especially for drum hardware. Another common fret material is EVO, a nickel-free alloy made from copper, tin, iron, and titanium, and best known for its gold color.
Back to tone. It's fair to assume that soft wood and Delrin frets will exhibit a stronger dampening in the upper range and less attack due to their structure and softness. But what about all those metals that are common on today's instruments? Almost every article about frets shares the same wisdom that big frets equal bigger tone, while smaller frets excel in intonation. The latter is at least theoretically imaginable, but the big-tone argument sounds as baloney as “red instruments sound more aggressive," since the mass differences between the fret sizes are rather minuscule. Fig. 1 shows two basic physical properties of common fret materials: density for mass, and hardness for their resistance to wear.
The approximate physical properties of several fret materials used on our instruments. Figure courtesy tuneyoursound.com/Henzig Collection
Luthiers and manufacturers often have an advantage, since they get very similar instruments on their workbenches and can better recognize small tonal changes from fret sizes or materials. In my own experience, I've been able to definitely notice changes when it comes to fret material, although never between sizes. Even though some say they can't hear any differences at all, stainless steel is definitely brighter sounding than softer brass and nickel-silver variants, and comes with that extra-high clack sound when played acoustically. EVO frets are, for the most part, somewhere in between the light and dark sonic sides.
To my knowledge, there are no actual studies or detailed comparative measurements of the different fret materials out there—just common wisdom and opinion. So, unfortunately, the information out there isn't based on measurements, but instead consists of highly subjective impressions, and differs widely. The one thing in common is that anecdotal evidence never mentions variations in the bass range at all, and the changes are only described by their influence on the upper range, with stainless steel and titanium being brightest. Nickel silver, on the other hand, is often described as “natural and warm sounding," which is a kind euphemism for sucked-up treble, or may just means that we're used to its sound.
The only real way to learn more is to extrapolate from what we already know about other parts of the instrument—especially the two other points of string contact: the bridge and the heavily discussed “special fret," the nut.
This era-authentic pairing—Gibson and Sunn—blends humbucking output with 40 watts of EL34 amp power and a pair of 12" speakers.
Cue metal music for this two-pickup 1962 Gibson EB-6 bass—one of just 68 in existence.
Gibson introduced its first electric bass guitar in 1953 and initially named it, aptly enough, Electric Bass, although it's better known today as the EB-1. It was followed by various EB models over the next several years, including the semi-hollow EB-2 in 1958 and the double-cutaway solidbody EB-0 in 1959. By the end of 1959, a semi-hollow 6-string bass debuted and was named the EB-6. Poor sales caused Gibson to replace it with a solid SG-style body version in late 1961 that retained the EB-6 name. The company catalog touted: “A new and exciting treat for bass players. A 6-string electric bass which gives a full octave lower guitar tuning on a regular bass scale length."
The new solidbody EB-6 started with a single pickup, as on the previous model, but soon added a second humbucker. (Only a small number of single-pickup models were produced.) The 1963 Gibson catalog described the instrument's features: “ New extra-thin custom-contoured double-cutaway body design. Slim, fast, low-action neck joins body at the 17th fret. One-piece mahogany neck, adjustable truss rod, rosewood fingerboard, pearl dot inlays. Combination bridge and tailpiece adjustable horizontally and vertically. Two powerful humbucking pickups. New nickel-plated string damper. Hand brace mounted on pickguard. Heavy-duty machine heads with metal buttons." As luck would have it, inadequate sales also caused the solidbody EB-6 to be discontinued by 1966 (but, according to the Gibson Shipment Totals book, two stragglers shipped in 1967). Only about 68 of these basses were manufactured, and Wes Montgomery and the Cars' Ben Orr are among the model's notable users.
The bar-style combination bridge allows horizontal and vertical adjustment and includes a mute before the bar.
The 1962 EB-6 pictured has the features typical of the two-pickup edition. These include a cherry red contoured SG-shaped solid mahogany body, a 30 1/2"-scale 1-piece mahogany neck joining the body between the 17th and 18th fret, a 20-fret rosewood fretboard with dot inlays, and two standard guitar humbuckers. On this example, the neck pickup is still a PAF. The nickel-plated parts include large-button Kluson tuners, a bar bridge/tailpiece, a metal hand rest between the pickups, and a string mute. The original price was $325. The current value for one in excellent all-original condition is $7,500.
The neck humbucker in this guitar is a vintage PAF. The original solidbody EB-6 had just one pickup, in the neck slot, like its semi-hollow ancestors.
The amp behind the bass is a 1967 Sunn Solarus combo. Two EL34 tubes push 40 watts of power through two 12" speakers. It has bright and normal channels with controls for treble, bass, and contour along with knobs for the vibrato and reverb. The current value for the amp is $750.
Note the classic early Gibson headstock profile as well as the nickel-plated large profile Kluson tuners.
Sources for this article include Gibson Electrics: The Classic Years by A.R. Duchossoir, Gibson Guitars: Ted McCarty's Golden Era—1948- 1966 by Gil Hembree, and Gibson Shipment Totals: 1937-1979 by Larry Meiners.