Photo 1 — Though it could present a challenge when palm muting, the bridge-integrated optical pickup on this Tom Lieber Spellbinder bass is almost fully shielded from ambient light.
Our classic combination of magnet and coil comes with a trait you can call either character or a limitation: a pickup-specific roll-off frequency that cuts off the upper range, mainly depending on the electric, magnetic, and geometric specs of the coil. Many of my non-musician friends are surprised that traditional magnetic pickups are commonly rated as low as 5 kHz, and ask why they should pay attention to the upper frequency limits when getting new hi-fi gear. Replying with "we have crash cymbals, too," is sometimes enough of an answer, but if they saw a real magnetic pickup's frequency-response curve, their hi-fi world would simply collapse. And—especially unfortunate for us bassists—these classic, magnetic designs also have limits in their lower frequency response.
Piezo pickups breaks these barriers on both ends of the spectrum. However, piezos often come with a rather harsh and dominating upper end that's not always pleasing to everyone's ears—especially when used with steel strings.
It may come as a surprise to some, but optical pickups actually first appeared in 1969 at the summer NAMM show in Chicago.
This is where optical pickups chime in. It may come as a surprise to some, but optical pickups actually first appeared in 1969 at the summer NAMM show in Chicago. A patent was granted to inventor Ron Hoag in 1973, but with Hoag's eventual retirement and his patents running out, the only optical pickups on the market in recent years have been made by LightWave Systems, for exclusive use in their own line of basses. However, this was different in their early years, when Lieber Guitars collaborated with Stanley Clarke and equipped a Spellbinder bass in 2001 with LightWave's bridge and massive circuit board (Photos 1 and 2).
One of the basic advantages of optical pickups is that their frequency range is theoretically unlimited—far out on both ends of our audible spectrum. Our hi-fi friends would be overwhelmed by the frequency response curve. And while every magnetic pickup sucks vibrational energy out of our strings—whether we switch them on or not—there is no interference between the pickup and string in any form with optical pickups (theoretical radiation or light pressure aside, of course).
In the same way we have different types of magnetic pickups with different electric and magnetic arrangements, there are also specifics that set optical pickups apart from each other. They all require some basics, like a light source and a light sensor, and can operate with visible or invisible and wide or extremely limited frequency ranges of light, but there are some basic constructional differences.
Early LightWave pickup systems came with a huge circuit board that didn't leave much wood on the backside.
Photo by Milo Stewart Jr.
Until recently, all available optical pickups were built for "transmission" mode, which is an arrangement where the source and sensor are on opposing sides of the string. What the sensor "sees" is the varying amount of shade from the vibrating string. Sounds simple, but the problem here is the positioning and calibration of the elements. As the string vibrates, there shouldn't be a complete coverage of light on the sensor. The result would be comparable to common clipping and you can't simply blow up the sensor's area to allow for more amplitude since your signal-to-noise ratio goes down significantly. The amplitude limits are why these pickups are often positioned close to—or even built into—the bridge and fully covered to shield them from ambient light. Worth noting is that even though the pickup elements are actually rather small, the large-ish covers required for shielding can get in the way when palm muting.
Light can sense all kinds of magnetic or non-magnetic string materials, so it's easy to switch between roundwound, flats, or even nylons, but this still often requires different setups. In transmission mode, you'll need to recalibrate whenever you're switching string gauges or readjust the bridge to optimize source and sensor usage. That said, the LightWave system's internal circuitry nowadays can support this setup process with LEDs that shine when the bridge sensors are correctly adjusted.
A second optical-pickup construction and design arrangement is called "reflection" mode, which we'll discuss next month. Reflection mode does make some of the aforementioned transmission-mode drawbacks easier to deal with, but the arrangement also comes with a load of new drawbacks of its own.Just as McCartney III was coming out in December, this column's 1967 Hofner 500/1 violin bass came into the shop. And to amplify the kismet, the Beatles were playing on the sound system when the bass' now-former owner brought it in to sell.
This model wouldn't be so iconic if McCartney could've afforded a Fender back in 1961, when the Beatles were literally getting their act together playing clubs in Hamburg. But his first Hofner was only $45. That one was stolen, and in '63 Hofner gave him a replacement, which is the bass we all know and love to hear.
Pardon my grunge: The control panel—three EQ sliders and two volume dials—shows some grit and dirt, well-earned from years in smoky clubs.
The Hofner violin bass dates back to 1955, when Walter Hofner designed the prototype. The small, hollow body and violin shape made it easy to carry and play—especially in comparison to Fender's Precision. The tone aimed for qualities that would appeal to both acoustic upright bass players and the expanding electric bass market—and with flatwound strings, it did just that, creating a fat, thumpy voice the amplified the sound so familiar on pop and jazz records of the '40s, '50s, and early '60s.
Most of what's changed about the Hofner 500/1 over the decades is the electronics, while the maple body, spruce top, rosewood fretboard, and dot inlays have remained a staple. The neck and bridge pickups had many iterations in the '50s and '60s. Originally, Hofner called them wide-spaced pickups, because they were located far apart, as close to the neck and bridge as workable. By '57, the bridge pickup was moved closer to the neck, to about mid-top. And in 1960, the black bar pickups Hofner used were replaced with toaster-style examples. A year later—and on McCartney's '61—the so-called twin-coil Cavern pickups arrived, along with the replacement of the tortoiseshell pickguard with a cream pearloid version. But '62 brought another shift, to diamond logo pickups, called that because of the diamond engraved on their covers. And a year later those were gone—nudged aside by staple pickups. In 1963, two-piece necks were also used on some 500/1s, and the two-on-a-strip tuners began to be replaced by standalone versions.
Here's a close-up look at the '67s neck-slot blade-style single-coil pickup—the seventh pickup variation for the 500/1 model.
But wait! There's more! The year of our Hofner, 1967, marked the introduction of single-coil blade pickups in the 500/1. Until this point, all of the aforementioned changes did little to alter the sound of the instrument. But the blades are different—hotter and more gainy. These pickups have two magnets on each side of a center blade, and they are ceramic, not alnico like earlier Hofner pickups. Their louder, more-forward tone is perfect for recording, and takes to digital tracking and mixing very well. The control set had slight variations over the years, but in 1967 was a sleek array of two volume dials and three responsive tone switches marked rhythm, bass, and treble.
Our 500/1 has an ebony two-piece floating bridge, and the fret saddle inserts have been removed to emulate the mod supposedly made by McCartney to get a more thuddy and muted sound. (A reissue version of the original bridge assembly is available.) The tuners on this bass were replaced with closed-back Grovers, which are a lot easier to turn than the small-button versions that came standard in '67.
Beneath its elegant, curved top, our 500/1's headstock has Grover replacements for the small-button OEM tuners, which went from two-to-a-strip to standalones in 1967.
This bass has been played a lot, and it shows in the finish wear and checking on its body. Plugging in made me want to start banging out some McCartney-style bass melodies and explore those loping, rich tones that were such an important element of the Beatles' sound. In the 1967 Hofner catalog, the 500/1 was listed at $345. Our example is tagged at $2,500. I hope this very collectable bass ends up with a musician who loves the Beatles as much as I do and puts it to work for at least another half-century.