Embracing and overcoming the quirky qualities of an under-appreciated hero of tube tone.
As a guitar player, I consider guitar amps to be tools. The more varied work I do, the more tools I need. There are some amps that excel in one or two things but often disappoint outside their playing field. These amps require experience to dial in good tones and to pair with guitars and other gear.
This month’s amp is an underdog—a jack-of-all-trades but master of none. It is a tool you can bring with you to any type of practice or gig, small or large, and it will deliver. It truly lives up to its name: the Pro Reverb. So, let me explain why I love this amp … but also what annoys me about it, and what I do to get around that.
In 1963, Fender offered a single-speaker Pro amp with front-mounted controls. Various Pros with top-based controls had been in Fender’s line since 1946. In ’65, the Pro was replaced by the Pro Reverb, loaded with 6L6GC power tubes in a classic Fender push/pull class-AB configuration. The Pro had either a single 15"CTS ceramic speaker or a Jensen C15N. The Pro Reverb came as a 2x12, with either Jensen C12Ns, Oxford 12L6, or Oxford 12T6 speakers—the latter a very underestimated speaker and comparable to the more famous C12N. In 1967, a silver-panel model followed and was available through 1969. Several other speakers, including models by Utah and Rola, came throughout the ’70s. And around 1978, a 70W version of the Pro emerged, with master volume and a push/pull boost, for a roughly five-year run.
The differences between the single- and dual-speaker black-panel Pros were most importantly the speaker configuration and the addition of reverb in the vibrato channel. There were two different versions of the output transformer: the 8-ohm 125A7A and 4-ohm 125A6A. This smaller output transformer is found in several medium-sized amps, such as the Vibrolux Reverb, Bandmaster, Tremolux, and also the rare and coveted 1964 Vibroverb.
How does it sound to play through a Pro Reverb, with its combination of the classic black-panel AB763 tone stack, dual 6L6GCs, a large and bass-y 2x12 cabinet with a 5U4GB rectifier tube and a small output transformer? Beautiful, full, clean tone at lower volumes and wildly cranked tones when pushed—much more than you’d expect from such a big Fender amp. Very few amps can do both of these sonic profiles.
Please find a Pro Reverb and plug in your Telecaster for a real Keith Richards experience, with one of the best rhythm tones there is.
The large open-back cabinet means you can point the Pro in almost any direction and fill the room or stage. At home, I sometimes want the most natural break-up from the amp at lower volumes, so I simply disengage one of the speakers and insert a 12AX7 in the phase inverter slot. I think the Pro Reverb delivers the most elegant and balanced cranked tones of all black-panel amps. I also love that the amp offers a bright switch that will support pedals and guitars well.
One annoying thing about the Pro is the lack of a mid pot. Since it is that good at delivering cranked tones, I would like more mids for heavier distortion at lower volumes without having to disengage speakers or swap tubes. A mid dial would also improve EQ control, for playing clean. Without a mid knob, I often have to dial the bass knob all the way down due to the bass-y cabinet and flabby output transformer. The solution is, as always, installing a switch on the back of the amp that toggles between the stock 6.8k mid resistor and a 25k. The Pro Reverb is the amp that benefits the most from this mod, I think.
Finally, do we really need a Pro Reverb in our toolbox? The Deluxe Reverb and Vibrolux Reverb are also low/medium wattage amps. Both are lighter, more snappy, more practical at home or in the studio, and don’t carry two large 12" speakers, which are overkill for the Pro’s light output transformer. The Super Reverb also breaks up—and with more punch, bass, treble, and attack overall. It is also more touch sensitive. The clean-voiced monster Twin Reverb is 17 1/2 to 22 pounds heavier but does not require more space than the Pro Reverb.
Given all the superior amps mentioned above, the answer to my question is still “yes.” Our underdog can almost do all of what these legendary Fender amps excel at. But none of them will sound as warm as the Pro Reverb when cranked.
Please find a Pro Reverb and plug in your Telecaster for a real Keith Richards experience, with one of the best rhythm tones there is. Also, try a Les Paul or SG in the bridge pickup position and you might consider selling all your overdrive pedals. A semi-hollow ES-style guitar with P-90s in neck and the amp dialed-in clean will urge you to learn jazz! Please, don’t just take my word for it. Go experiment.
This bruising 60-watt powerhouse is ready for anything, with three speakers, five reverb and tremolo controls, and a fat boost.
I'd like to pay respect to the Fender Vibro-King. I still remember how I first admired it, brand new in guitar magazines, in 1994. It was the raw, wild, and blonde Viking cousin of the classic vintage Fender amps. I immediately wanted one and got my first in 2004. So, let me share my view on this flagship from Fender's Custom Shop.
The most recent model, the 20th Anniversary Edition, was discontinued in 2014. Other than a change from EL84 to 6V6 tubes in the reverb section for improved durability, the amp circuit was fairly consistent during its years in production. There were various color schemes: blonde, black, light brown, dark brown, naked maple, and hand-tooled Tolex. And for its 3×10 array, Fender used various speakers, starting with blue-framed Eminence alnicos, then Jensen P10Rs and Celestions in custom models.
With dual 6L6GC power tubes and a class AB push/pull configuration, its big-iron transformers produce a whopping 60 watts at 2 ohms. The large power transformer contributes significantly to an overall weight of about 70 pounds. With the right or wrong speakers, this amp can weigh as much as 88 pounds. But contrary to older, less robust vintage Fenders, the Vibro-King's massive, solid cabinet can carry heavy speakers and deliver tons of punchy bass response. A set of Weber 10A150s or Eminence Swamp Thangs has never been more fun. Fender did offer a matching 2×12 extension cabinet for those who wanted a full Vibro-King stack, but I find it loud enough with the three-speaker complement.
Sonically, the Vibro-King falls between tweed and black-panel-era Fenders, whether sparkling clean or wildly cranked, and even at low volume. The amp's distortion is attributable to the design of the preamp section and the lack of a negative feedback loop in the power section. You can dial in a wide span of tones using volume, EQ, and the fat boost—more than a typical vintage Fender amp.
Players seem to either love or hate the Vibro-King. I suspect the haters haven't experimented enough with speakers and EQ settings. The Vibro-King also has an unusual control panel, with a dedicated reverb section, with dwell, mix, and tone dials, and the usual tremolo depth and intensity, plus volume, treble, bass, and mid knobs, and a slider for that fat boost.
If the amp is set in its sweet spot, the footswitchable fat boost will allow you to flip between a clean tone for rhythm or a cranked-up lead tone for solos.
I've kept the light Eminence alnico speakers in my own 1994 Vibro-King. I love the loose low end and strong upper mids. I've found some of the best modern Jimmie Vaughan tones with my amp, but it can also easily do Keith Richards. The quick, snappy response and touch sensitivity allows trebly nuances from your fingertips, strings, and fretboard. If you're into more generic tones or the familiar black-panel Fender sound, Jensen P10Rs or C10Qs will do that for you, too.
Some advice to those who are not into reverb or tremolo: Steer away from this amp! As mentioned, five out of nine faceplate controls are dedicated to reverb and tremolo. If you're into that, the Vibro-King is a delight. The reverb section has the same controls as the classic vintage Fender standalone reverb unit and offers a huge selection of tones. However, the EL84 Vibro-King is known for occasional issues with the reverb circuit, causing overwhelming waves of reverb and burnt tubes. But you can get lucky. I had an EL84 reverb tube in mine for over 15 years.
If the amp is set in its sweet spot, the footswitchable fat boost will allow you to flip between a clean tone for rhythm or a cranked-up lead tone for solos. For some players, this eliminates the need for a boost pedal. It's also worth noting that the tone controls are quite sensitive and differently biased than black-panel and silver-panel Fenders. Expect to spend some time finding good settings.
Here are two tone strategies to try:
- Low volume and high/maximum EQ settings with the fat boost on, which creates a tweed/blonde tone with little clean headroom and lots of preamp gain at low volumes.
- High volume and low EQ settings with the fat boost off, to craft a clean, scooped, black-panel tone, with little or no preamp gain and lots of headroom.
If you haven't played a Vibro-King, you're missing an exciting experience. It's not the amp for everyone, but for some it's the Fender amp they've always looked for. Skeptical? Watch the YouTube clip below of Gary Clark Jr. onstage with the Rolling Stones and John Mayer. As difficult as it can be to cut through when four guitarists are playing together, Clark tears it up with a humbucker-loaded ES-335 through a Vibro-King. Until the next time, may the tone be with you.
The Rolling Stones, Gary Clark Jr. & John Mayer_Going Down Live
An unsung sleeper from the black- and silver-panel years sees its DNA scrambled to intriguing ends.
Classic cleans and excellent pedal-platform versatility. Nice onboard reverb and tremolo. Light weight for an amp of this size.
No output-reduction feature.
Fender '68 Custom Pro Reverb
Fender's '68 Custom series won plenty of fans by resurrecting the stylish silver-panel amps of the late '60s and '70s and making some of those models into more modern gigging machines. One of the newest additions to the lineup is the '68 Custom Pro Reverb—an evolution of an amp that debuted as a black-panel model in 1965.
The original Pro Reverb is considered a great all-around stage amp, and remains a relative bargain among vintage Fenders. But the reconfigured '68 Custom Pro Reverb both adds and subtracts features to better suit the needs of contemporary players, and there are significant differences between the original Pro and this newest edition. Where the original was a 2-channel 2x12, the new incarnation is a lighter and more compact 1x12, has a single channel, and adds a midrange control. But it's still 40 watts and most of the features remain the same, making it a logical next-step-up from the popular Deluxe Reverb.
Eliminating the underutilized normal channel from the original and adding the handy midrange control still equals a very streamlined control panel: volume, treble, middle, bass, reverb, and tremolo speed and intensity—a combination any Fender fan can love and relate to. The power and standby switches are on the back panel, where you'll also find two jacks for the onboard and extension speakers, and a TRS jack for the included two-button reverb and tremolo switch.
Much like its '60s predecessor, the '68 Custom Pro Reverb generates 40 watts from a pair of 6L6GC output tubes, with three 12AX7s and two 12AT7s in the front end. It lacks the original's tube rectifier—instead using solid-state diodes to convert AC to DC (as many other Fenders were doing in the '60s anyway). Players love tube rectifiers for their saggy, compressed attack, but Fender claims to have made up for the absence of a tube rectifier by using a transformer with higher-than-usual copper resistance, which helps replicate the higher forward impedance—and sag—a rectifier tube would provide.
Although it's compact and relatively light, the Pro Reverb can still be a loud amp.
A more obvious deviation from tradition is the inclusion of a single 12" Celestion Neo Creamback speaker. It's built around a lightweight neodymium magnet rather than a heavier ceramic one, like you'd see in the speakers from a vintage black-panel Pro Reverb. It's a critical part of a slimming effort that, along with a compact 22" x 17" x 9" meranti plywood cabinet, reduces the combo's overall weight to a manageable 35 pounds (originals weighed closer to 53 pounds).
The rugged printed circuit board includes a few thoughtful updates to the original circuit— most notably a reduction in the output stage's negative feedback, which adds a little more touch sensitivity. And the tremolo is tube-driven and grid-biased—borrowed from the vintage Princeton Reverb amp for a warmer throb. Elsewhere things stay close to vintage spec. The reverb is still a classic tube- driven Fender circuit that feeds a long spring pan mounted at the bottom of the cab. The transformers are custom made by Schumacher, which supplied these components to Fender in the '60s. For the most part, the Pro features the same preamp circuit that helped to make black- and silver-panel Fender amps so famously glassy, clear, bright, and slightly scooped sounding.
Given that the '68 Custom Pro doesn't attempt to be a period-correct reissue, it occasionally leaves us wanting for a few additional non-vintage conveniences. A master volume control is almost anathema to this circuit, but some form of output-reduction mode—a half-power switch, an onboard attenuator, or a voltage-reduction circuit—would be useful. Although it's compact and relatively light, the Pro Reverb can still be a loud amp and the inability to crank it up for natural bite and sting at lower decibel levels might limit its appeal to some players.
Whether paired with a Fender Telecaster, a Gibson ES-335, a P-90-driven Novo Serus J, or a variety of overdrive pedals, the '68 Custom Pro Reverb delivers impressive variations of the vintage Fender amp sounds we know and love, and feels very familiar and dynamic in the process.
Players generally covet vintage Fender amps for their stellar cleans and creamy edge-of-breakup sounds. The '68 Custom Pro Reverb delivers on all counts. It's bright and clear without being harsh or brittle, and slightly mellow in the mids without sounding timid. It's a classic tone for anything from pop to country to jazz to blues, and it's an ideal foundation for pedals. Add the sumptuous reverb and tremolo to this palette—both of which impressively emulate their '60s predecessors—and there are many moods to conjure before you even add a stompbox.
Moving the amp from to clean to slightly dirty overdrive—at least with a Telecaster bridge pickup—is the difference of going from 4.5 to 5 on the volume control. Here, the '68 Custom Pro Reverb reveals the more aggressive side of its personality. Breakup is juicy and biting with just enough sag to compress hard pick attack without going mushy. The Pro can get a little raunchy and loose when pushed too far—especially when humbuckers or P-90s are involved. But it's still a delicious sound. (I also easily achieved all of these sounds at lower volume levels using the attenuator in a Mesa CabClone IR+. A similar attenuator might open up many such options).
Fender did a great job re-imagining one of their real unsung '60s combos as an amp that's probably more useful for most modern players than a detail-perfect reissue would have been. It does a great job of capturing those iconic black- and silver-panel tones at an accessible price, all in a lighter, more convenient package. Some form of output reduction would have been a plus, but even as is it represents a formula with a lot of practical appeal.