The EBow is a handheld, battery-powered electromagnetic string driver designed primarily for electric guitars and other stringed instruments, enabling monophonic infinite sustain and rich harmonic overtones by vibrating a single string at a time without physical contact.[1][2] Invented by Greg Heet in the late 1960s as an evolution from earlier prototypes like the Voicitar, it debuted in its modern handheld form at the 1976 NAMM Show in Chicago, where early adopters such as Jerry Garcia purchased units.[3][2]The device operates through direct string synthesis: a pickup coil senses the string's vibration to generate an electrical signal, which powers a secondary electromagnetic coil that exerts a time-varying magnetic force on the string, sustaining its oscillation and mimicking sounds of bowed strings, horns, or woodwinds.[1][4] Key features include adjustable sensitivity via a thumbwheel for dynamic control, harmonic modes for varied tonal shapes, and compatibility with guitars, basses, and even non-traditional applications like drums, though it is limited to one string due to its monophonic design.[1][2] Over time, models have evolved from the original chrome version to self-lubricating plastic iterations in the 1980s and the latest 2024 edition, with variations available in materials like wood and glass.[3]Widely adopted in rock, alternative, and experimental music, the EBow has been used by artists including David Bowie on live performances of "Heroes," R.E.M. on "E-Bow the Letter," Radiohead on "My Iron Lung," and U2 on tracks from The Unforgettable Fire and "Magnificent," creating ethereal, sustained textures that enhance atmospheric and lead guitar parts.[5] Its influence extends to bassists like Michael Manring and percussionists experimenting with bowed effects, underscoring its versatility across genres since its commercial release.[5][3]
History
Invention and Early Development
The EBow was invented in 1969 by Greg Heet, an American guitarist and audio engineer working at Heet Sound Products in Los Angeles, California.[2][6] Heet's concept drew from electromagnetic string excitation principles, aiming to create a device that could initiate and sustain string vibrations on electric guitars without physical contact.[7] Early development involved experimenting with feedback loops using coils and tape heads to achieve self-sustaining string motion, evolving from prior ideas like the Voicitar—a guitar modification for vocal-string synthesis.[3]Prototyping presented significant challenges, particularly in aligning the electromagnetic field precisely across three axes to ensure stable vibration of individual strings.[3] Heet struggled with inconsistent sustain and the impracticality of early handheld designs, which initially incorporated makeshift components like nails and epoxy-encased circuits.[3] These issues were addressed through iterative testing, resulting in a compact, battery-powered unit powered by a standard nine-volt battery that replaced the traditional guitar pick in the player's hand.[8][3]Heet filed a patent application for the device on December 2, 1976, which was granted as US Patent 4,075,921 on February 28, 1978, describing it as a "string instrument vibration initiator and sustainer."[7] The EBow made its public debut at the 1976 NAMM Show in Chicago, marking its first commercial availability and introducing musicians to this innovative handheld electromagnetic tool.[3][9] This launch followed years of refinement, establishing the foundational design that emphasized monophonic string driving via magnetic feedback.[7]
Model Evolution and Production
The EBow's model evolution began shortly after its 1976 debut, with refinements aimed at enhancing usability and reliability. In 1983, Heet Sound Products introduced the second-generation model, featuring a black plastic enclosure with a red logo, which replaced the original chrome finish to improve gliding over strings and reduce manufacturing defects from plating processes. This version added a manual on/off switch for easier control, eliminating the problematic automatic activation circuit that had caused a high reject rate in early units, and incorporated a more powerful drive circuit for stronger string excitation.[10]By 1989, the third-generation model emerged with a black enclosure and white logo, incorporating circuit enhancements that improved sensitivity and response time, allowing for quicker attack and better overall performance without altering the core design significantly. These updates, including a refined "licked-circuit" modification for increased drive, have influenced subsequent production and remain in use today.[11]The fourth model, the EBow Plus, was released in 1998 and received further updates in 2024, including the PlusEBow Fire variant with enhanced sensitivity, faster response, and improved tone control. It introduced key features such as a blue LED indicator for power and mode status, a three-position switch enabling selection between standard sustain and harmonic modes (the latter producing an octave-up effect with enriched overtones), and enhanced sustain capabilities for more expressive play, and remains the primary model in continuous production as of 2025. Heet Sound Products has maintained uninterrupted manufacturing of the EBow since 1976 at its facilities in Southern California, utilizing potted electronics for durability against stage wear, with no major model discontinuations reported.[10][3][12]Powered by a standard 9V battery, the EBow Plus typically provides 12 to 24 hours of operation depending on usage intensity, making it suitable for extended performances. The device is widely available through authorized retailers such as Guitar Center and Reverb, ensuring accessibility for musicians globally.[13][14]
Design and Operation
Principle of Operation
The EBow functions through an electromagnetic feedback circuit that detects and reinforces string vibrations on an electric guitar, enabling indefinite sustain without physical contact between the device and the string. A sensor coil within the EBow captures the motion of a ferrous guitar string, inducing a voltage proportional to the string's velocity and frequency via electromagnetic induction. This signal is then amplified internally using an operational amplifier powered by a 9V battery.[7]The amplified signal drives a separate output coil, generating a pulsating electromagnetic field oscillating at the detected frequency. This field exerts a varying magnetic force on the ferromagnetic string, driving continued vibration and effectively "bowing" the string to sustain its fundamental frequency and harmonics.[7]The focused nature of the electromagnetic field limits the EBow to exciting a single string at a time, as the field strength diminishes rapidly beyond the targeted area. Unlike traditional magnetic pickups, which only sense vibrations to produce an audio signal, the EBow actively drives the string through this closed-loop feedback, eliminating the need for initial plucking once sustain is engaged and allowing vibrations to persist as long as power is supplied.[15][7]
Controls and Features
The EBow features a simple user interface centered around a three-position slide switch that selects between off, normal mode, and harmonic mode. In normal mode, the device sustains the fundamental frequency of the string, producing a smooth, violin-like sustain, while harmonic mode, introduced with the EBow Plus in 1998, excites an octave higher for enhanced upper harmonics and ethereal tones.[11][10]Adjustment of the electromagnetic field intensity, referred to as drive, is achieved by varying the proximity and pressure of the EBow to the targeted string; closer positioning increases drive for louder volume and longer sustain, while lifting reduces it for controlled decay.[11] Similarly, sensitivity to string input, akin to gain, is fine-tuned by the device's distance from the guitar's pickup, with closer placement boosting attack and brightness for dynamic response.[11]EBow Plus models include a blue LED indicator at the drive channel end, which illuminates to show power status and active mode, aiding precise positioning over the string.[11]The device is powered by a standard 9-volt battery housed in an accessible compartment on the underside, providing approximately 20-30 hours of continuous operation depending on usage intensity.[13]For integration, the EBow relies on the guitar's existing output jack and amplification setup, with no dedicated output on the device itself, though it is compatible with standard guitar accessories like effects pedals and amplifiers for enhanced tonal shaping.[16]
Musical Applications
Techniques and Effects
The EBow is typically held or positioned over a single guitar string, approximately 1-2 inches above it to optimize the electromagnetic field's interaction with the string's vibration, mimicking the action of a violin bow.[15] For best results, it should be aligned parallel to the string and placed near the bass pickup, where the "HotSpot"—the area closest to the pickup—produces the loudest and most responsive sustain.[15] Tilting or pressing the device closer to the string intensifies the drive, while gliding it along the string length allows control over dynamics and tone.[17]Key techniques include slowly plucking or tapping the string to initiate vibration, followed by the EBow's sustain for bowed-like notes that can last indefinitely.[15] Volume swells are achieved by gradually moving the EBow toward or away from the pickup, creating smooth crescendos or fades reminiscent of orchestral swells.[15] In harmonic mode, gliding the device produces wah-like effects or enhanced overtones; combining it with distortion pedals simulates pick attacks, while reverb or delay pedals amplify ethereal textures and spatial depth.[15][17] Rocking the EBow near the HotSpot enables tonal slurs, and rapid sideways slides between strings facilitate arpeggios with seamless transitions.[15]The primary effects include infinite sustain that emulates the continuous tone of a violin or cello, rich in harmonics for lush, singing lines.[15] On electric guitars, it generates synth-like timbres or horn/woodwind imitations through proximity adjustments; harmonic overtones yield dreamy, ambient washes when processed with chorus or shimmer effects.[17] For bass guitars, the EBow sustains low-end drones effectively with light-gauge strings and added distortion, though alignment requires thumb-and-forefinger grip or tilting for precision.[18] On acoustic guitars equipped with magnetic pickups, it produces sustained harmonics and soundscapes, albeit with slower decay and lower volume compared to electrics; piezo or microphone pickups yield quieter results without a defined HotSpot.[15][18]Limitations include its monophonic nature, exciting only one string at a time, which restricts chordal playing unless arpeggiated.[17] Proximity to the amplifier can induce unwanted feedback, and high frets (beyond the 17th) or the high E string may sustain less reliably due to weaker field interaction.[15] The device requires amplification for optimal output, as its signal dramatically boosts the instrument's volume, potentially overwhelming unadjusted setups.[15]Adaptations extend to non-guitar instruments like the harp or Chapman Stick, where the EBow induces resonant sustains on individual strings for experimental drones and textures, often in ambient or unconventional contexts.[18] On experimental setups, such as custom string installations, it facilitates unique vibrations and infinite decays, enhancing improvisational sound design.[18]
Notable Artists and Recordings
The EBow gained prominence in the 1980s through pioneering rock guitarists who leveraged its infinite sustain for distinctive sonic textures. Stuart Adamson of Big Country employed the device on tracks like "The Storm" from their albums, producing bagpipe-like drones that defined the band's anthemic quality.[5]In the 1990s, the EBow became a staple in alternative and shoegaze genres, often highlighting its capacity for bowed-string emulation. Peter Buck of R.E.M. prominently featured it on the 1996 single "E-Bow the Letter" from New Adventures in Hi-Fi, a duet with Michael Stipe that directly referenced the device in its title and used it to generate violin-esque swells throughout the arrangement.[5][19]Post-2000, the EBow influenced ambient and experimental rock, expanding beyond traditional lead lines into atmospheric roles. Ed O'Brien of Radiohead applied it to tracks like "My Iron Lung" from The Bends (1995) and later works, creating swelling string-like pads that evoked orchestral depth.[5]Sigur Rós incorporated the device for ambient swells in their post-rock soundscapes, notably on "Untitled #6 (E-Bow)" from the 2002 album (), where it blended seamlessly with bowed cello elements.[5][19]From the 2010s to 2025, the EBow persisted in live and studio settings across rock subgenres, demonstrating its enduring versatility. The Edge of U2 featured it on tracks from The Unforgettable Fire (1984) and "Magnificent" from No Line on the Horizon (2009), creating soaring, delay-drenched solos.[5][19] In recent years, modern post-rock bands continued to adopt it; for instance, the 2023 album End by Explosions in the Sky highlighted EBow-driven sustains in tracks like "Ten Billion People," underscoring its role in evolving ambient guitar palettes.[20]The EBow's broad adoption is evident from the official manufacturer site, which lists over 100 artists across genres.[5]