This sketch and referenced patent from 1943 for a headless, solidbody violin represents what may be the very first piezo-electric bridge transducer.
Along with a ringing endorsement from Glen Campbell, Ovation engineer Jim Rickard’s design for a piezo-equipped bridge system would help propel the new company’s popularity in the ’70s.
Over the course of my past few columns, we’ve discussed the benefits and challenges of amplifying an acoustic instrument, as well as choosing the best gear for a particular situation. As promised, we’ll now look at the specific elements in the amplification signal chain in more detail.
The signal chain actually starts with plucking a string. The mechanical energy created by this action then transfers to the instrument through the saddle mounted on the bridge. This energy “excites” the instrument’s body by making it resonate, which in turn excites the air in the room. When amplifying an acoustic instrument, the mechanical energy is captured by some sort of electromechanical device, converted to an electrical signal, and then fed to a sound-reinforcing system, such as an amp or PA, for volume enhancement. Of course, this electrical signal can also be fed into a recording device too.
Mechanical energy can be converted into electrical energy (aka transduction) by either direct or indirect methods. The indirect method is accomplished with microphones that react to the pressure changes in the air caused by the vibrating instrument. With indirect conversion, the nature of the room acoustics and other ambient artifacts (noise) have a significant effect on the ultimate electrical signal that is produced.
The direct conversion mode is realized by attaching a vibration sensor or force sensor directly to the instrument. For obvious reasons, the electrical signal produced in this mode is much more immune to room acoustics and ambient artifacts than a signal produced in the indirect mode.
In my next few columns, we’ll explore one direct-conversion device in particular— the undersaddle transducer (UST). There are many types of direct-conversion transducers for acoustic guitars, but the undersaddle variety is by far the most widely used by today’s manufactures and builders. And drilling down one step further, we will be focusing on piezo-electric undersaddle devices. While there are a few examples of non-piezo undersaddle designs, over 99 percent of the devices produced today use piezo technology.
Piezo-based saddle transducers for musical instruments have been around for quite some time. Some early uses of piezoelectric transducers for pianos show up in patent literature as early as 1931, and their use in bowed and plucked instruments would follow soon after. In fact, one of the earliest designs on record is described in a patent issued to Hugo Benioff in 1940. This patent references a headless, solidbody violin with what I believe is the first piezoelectric bridge transducer! These devices have evolved significantly in the past 30 years and a modern version of this type of instrument, designed and marketed by Ned Steinberger, has become popular with today’s plugged-in violinists.
Piezo-equipped bridge systems for acoustic instruments were beginning to be used in the early ’60s by companies like Gibson on their C1-E electric-classical guitar. The Baldwin Piano Company also produced an electric-classical model called the 801CP that was used by Jerry Reed, Glen Campbell, and Willie Nelson. A drunk destroyed Nelson’s 801CP beyond repair, but he liked the pickup so much he had it installed in “Trigger,” the famous Martin N-20 he still plays today.
When Charlie Kaman started Ovation Guitars in 1966, the company was small and just beginning to receive attention for its radical approach to guitar design. But suddenly, along came Glen Campbell. Apparently Charlie wanted Campbell to use his guitars and Campbell, who was using his Baldwin at the time, agreed to do so if they could provide him with a built-in pickup similar to Baldwin’s Prismatone. Ovation engineer Jim Rickard went to work, came up with a design, and applied for a patent that was granted in 1973. This pickup became the foundation for the entire line of Ovation acoustic-electric guitars, which would quickly gain in popularity with Campbell as an endorsee and the huge exposure he gave the company on CBS’s The Glen Campbell Goodtime Hour television show.
Suddenly, a revolution was underway: U.S. guitar manufacturers began producing a new category of guitars with built-in piezo-saddle bridges, and this revolution would continue to gain momentum throughout the ’70s with the entrance of Takamine and other Japanese manufacturers.
Chris Martin, CEO of Martin Guitars, often says the emergence of the amplified acoustic guitar actually saved the acoustic guitar industry from the disastrous condition it was in during the late ’70s and early ’80s. These new acoustic guitars could now hold their own in any venue and at any volume. Just look at the great success of modern country music, the rock ballad, the modern folk movement, progressive bluegrass, and the emergence of the Seattle music scene. And what about MTV’s wildly successful Unplugged series? None of these would have been possible without amplified acoustic guitars.
Next time, we’ll look at some of the early built-in systems in detail and find out why some worked and others didn’t.
Larry Fishman holds
more than 30 patents in
transducer and musical
instrument design. He is
president and founder
of Fishman Transducers,
which he began in his
garage in 1981. In the early ’90s, he
also co-founded and managed Parker
Guitars (which was later sold to U.S.
Music Corp.) with his friend Ken Parker.
Silos features six presets, tap tempo, one full second of delay time, and three voices—two of which are styled after bucket-brigade and tape-delay sounds. In the $150 price category, it’s not unusual for a digital delay to leave some number of those functions out. And spending the same money on a true-analog alternative usually means warm, enveloping sounds but limited functionality and delay time. Silos, improbably perhaps, offers a very elegant solution to this can’t-have-it-all dilemma in a U.S.-made effect.
A More Complete Cobbling Together
Silos’ utility is bolstered by a very unintimidating control set, which is streamlined and approachable. Three of those controls are dedicated to the same mix, time, and repeats controls you see on any delay. But saving a preset to one of the six spots on the rotary preset dial is as easy as holding the green/red illuminated button just below the mix and preset knobs. And you certainly won’t get lost in the weeds if you move to the 3-position toggle, which switches between a clear “digital” voice, darker “analog” voice, and a “tape” voice which is darker still.
“The three voices offer discernibly different response to gain devices.”
One might suspect that a tone control for the repeats offers similar functionality as the voice toggle switch. But while it’s true that the most obvious audible differences between digital, BBD, and tape delays are apparent in the relative fidelity and darkness of their echoes, the Silos’ three voices behave differently in ways that are more complex than lighter or duskier tonality. For instance, the digital voice will never exhibit runaway oscillation, even at maximum mix and repeat settings. Instead, repeats fade out after about six seconds (at the fastest time settings) or create sleepy layers of slow-decaying repeats that enhance detail in complex, sprawling, loop-like melodic phrases. The analog voice and tape voice, on the other hand, will happily feed back to psychotic extremes. Both also offer satisfying sensitivity to real-time, on-the-fly adjustments. For example, I was tickled with how I could generate Apocalypse Now helicopter-chop effects and fade them in and out of prominence as if they were approaching or receding in proximity—an effect made easier still if you assign an expression pedal to the mix control. This kind of interactivity is what makes analog machines like the Echoplex, Space Echo, and Memory Man transcend mere delay status, and the sensitivity and just-right resistance make the process of manipulating repeats endlessly engaging.
Doesn't Flinch at Filth
EarthQuaker makes a point of highlighting the Silos’ affinity for dirty and distorted sounds. I did not notice that it behaved light-years better than other delays in this regard. But the three voices most definitely offer discernibly different responses to gain devices. The super-clear first repeat in the digital mode lends clarity and melodic focus, even to hectic, unpredictable, fractured fuzzes. The analog voice, which EQD says is inspired by the tone makeup of a 1980s-vintage, Japan-made KMD bucket brigade echo, handles fuzz forgivingly inasmuch as its repeats fade warmly and evenly, but the strong midrange also keeps many overtones present as the echoes fade. The tape voice, which uses aMaestro Echoplex as its sonic inspiration, is distinctly dirtier and creates more nebulous undercurrents in the repeats. If you want to retain clarity in more melodic settings, it will create a warm glow around repeats at conservative levels. Push it, and it will summon thick, sometimes droning haze that makes a great backdrop for slower, simpler, and hooky psychedelic riffs.
In clean applications, this decay and tone profile lend the tape setting a spooky, foggy aura that suggests the cold vastness of outer space. The analog voice often displays an authentic BBD clickiness in clean repeats that’s sweet for underscoring rhythmic patterns, while the digital voice’s pronounced regularity adds a clockwork quality that supports more up-tempo, driving, electronic rhythms.
The Verdict
Silos’ combination of features seems like a very obvious and appealing one. But bringing it all together at just less than 150 bucks represents a smart, adept threading of the cost/feature needle.
EarthQuaker Devices Silos Multi-generational Time Reflection Delay Pedal
In this episode, we’re celebrating the thrill of guitarmony, sick riffs, and driving 8th-note rhythms by talking about Judas Priest. Before getting ready for this episode, neither of your esteemed hosts had ever delved into the Priest discography beyond the rock-radio hits and Beavis and Butthead—though we’d both spent our time with Heavy Metal Parking Lot. Since so many of the GOATs hold the band in the highest of regard, we knew that K.K. Downing and Glenn Tipton belonged on this list, so we embarked on a journey to find out why.
After hours of listening and watching, we’re happy to report that we get it. From their debut, 1974’s Rocka Rolla, through 1980’s British Steel, deep into the ’80s-production era with 1986’s Turbo, and through the speed-metal bravado of 1990’s Painkiller, plus live videos and records—the super-loud US Festival performance and the crushing Unleashed in the East record—we found a lot that we love.
