What is the difference between the narrow and wide versions of the Prefix Plus-T?

The narrow version features an under-saddle pickup designed for bridge slots that are 3/32" (2.3 mm) wide. The wide version is intended for 1/8" (3.2 mm) bridge slots. Choosing the correct width is essential for proper string balance and signal output.

Does the Prefix Plus-T include a built-in tuner?

Yes, it includes a digital chromatic tuner. The tuner works even when the guitar is not plugged into an amplifier, making it a convenient tool for practice and stage preparation.

How does the 'Contour' control work on this preamp?

The Contour control is a semi-parametric EQ that allows you to choose a specific frequency and then boost or cut it. This provides more precision than a standard fixed EQ, helping to remove 'muddy' mids or add specific clarity.

What is the purpose of the Notch filter?

The Notch filter is designed to combat acoustic feedback. It allows the user to 'dial out' the specific narrow frequency that is causing the guitar to howl, without significantly altering the overall tone of the instrument.

Is the Prefix Plus-T suitable for home recording?

Yes, its 'ultra-quiet' electronics make it a strong candidate for direct recording. While many prefer microphones, the Prefix Plus-T provides a clean, reliable signal that requires very little post-processing noise reduction.

How is the preamp powered?

The system is typically powered by a single 9-volt battery. Access is usually provided via the flip-top preamp housing, allowing for quick battery changes without removing the entire unit.

Does this unit require professional installation?

Professional installation is highly recommended because it requires cutting a hole in the side of the guitar and precisely fitting the under-saddle pickup. Incorrect installation can damage the instrument or result in uneven string volume.

What does the Phase switch do?

The Phase switch reverses the polarity of the signal. This is useful for improving bass response at low volumes and can help cancel out feedback when playing at higher volumes near an amplifier.

How does the 'Brilliance' slider affect the sound?

The Brilliance control targets the very high frequencies of the guitar's output. Increasing it adds 'air' and shimmer to the sound, which can help the guitar cut through a dense mix of other instruments.

Can I use this preamp with a nylon-string guitar?

Yes, provided the bridge slot matches the narrow pickup width. The Prefix Plus-T is commonly used on both steel-string and nylon-string acoustic guitars to provide professional-grade amplification.

Is the Prefix Plus-T a quiet preamp?

Fishman describes the electronics as 'ultra-quiet.' This means the internal circuitry is designed to minimize the self-noise (hiss) often found in cheaper onboard preamp systems.

How does this compare to a Behringer PP400?

The Behringer PP400 is a phono preamp for turntables, whereas the Prefix Plus-T is an onboard acoustic guitar preamp. They serve entirely different purposes and are not interchangeable in a signal chain.

Gear article

Fishman Prefix Plus-T Onboard Preamp

The Fishman Prefix Plus-T is an onboard acoustic guitar preamplifier system designed for professional installation, featuring high-quality electronics and a narrow-format under-saddle pickup. It incorporates comprehensive tone-shaping tools, including semi-parametric controls and a built-in digital chromatic tuner, to provide a versatile stage-ready solution for acoustic musicians.

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Overview

The Fishman Prefix Plus-T is a flagship side-mounted preamp system designed to be integrated directly into the body of an acoustic guitar. This specific iteration features a narrow-format under-saddle pickup, making it compatible with instruments that have thinner bridge slots. The system is engineered to provide 'ultra-quiet' performance, ensuring that the natural resonance of the guitar is amplified without introducing unwanted electronic hiss or hum.

Key Features and Controls

One of the defining characteristics of the Prefix Plus-T is its sophisticated equalization suite. Beyond standard Volume, Bass, and Treble controls, it features a semi-parametric 'Contour' control. This allows the player to target specific frequencies for boosting or cutting, providing much greater flexibility than a fixed-frequency EQ.

Additional utility features include: * Digital Chromatic Tuner: A built-in tuner that can be used without plugging the guitar into an external amplifier. * Brilliance Control: Adjusts the high-end shimmer and presence of the tone. * Notch Filter: A critical tool for suppressing acoustic feedback by cutting a narrow band of problem frequencies. * Phase Switch: Assists in improving bass response at low volumes and further controlling feedback at high volumes.

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Sound Character

The Prefix Plus-T is known for its transparent and articulate sound. By utilizing Fishman's under-saddle pickup technology, the system captures the percussive attack and harmonic detail of the strings. The 'ultra-quiet' electronics ensure that the signal remains clean, which is essential for both studio recording and large-scale live performances where noise floor issues can become prominent.

Suitability and Installation

This unit is primarily suited for professional guitarists who require a permanent, high-fidelity amplification system. Because it is a 'Narrow' version, it is specifically designed for guitars with a 3/32" (2.3 mm) saddle slot width. It is an ideal choice for musicians who perform in varying acoustic environments and need the on-board tools—such as the Notch filter and Phase switch—to manage feedback in real-time.

Comparison to Alternatives

While there are many preamp solutions on the market, the Prefix Plus-T occupies a specific niche for side-mounted systems. Unlike pedal-based preamps such as the Vox Valvenergy Tone Sculptor or the Boss BP-1W, which offer external tone shaping, the Fishman system provides immediate access to controls on the guitar body. Compared to minimalist inline preamps like the sE Electronics DM2 TNT or the TritonAudio FetHead, the Prefix Plus-T offers a far more comprehensive suite of EQ and feedback management tools, though it requires permanent physical modification to the instrument.

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Frequently asked questions

What is the difference between the narrow and wide versions of the Prefix Plus-T?: The narrow version features an under-saddle pickup designed for bridge slots that are 3/32" (2.3 mm) wide. The wide version is intended for 1/8" (3.2 mm) bridge slots. Choosing the correct width is essential for proper string balance and signal output.
Does the Prefix Plus-T include a built-in tuner?: Yes, it includes a digital chromatic tuner. The tuner works even when the guitar is not plugged into an amplifier, making it a convenient tool for practice and stage preparation.
How does the 'Contour' control work on this preamp?: The Contour control is a semi-parametric EQ that allows you to choose a specific frequency and then boost or cut it. This provides more precision than a standard fixed EQ, helping to remove 'muddy' mids or add specific clarity.
What is the purpose of the Notch filter?: The Notch filter is designed to combat acoustic feedback. It allows the user to 'dial out' the specific narrow frequency that is causing the guitar to howl, without significantly altering the overall tone of the instrument.
Is the Prefix Plus-T suitable for home recording?: Yes, its 'ultra-quiet' electronics make it a strong candidate for direct recording. While many prefer microphones, the Prefix Plus-T provides a clean, reliable signal that requires very little post-processing noise reduction.
How is the preamp powered?: The system is typically powered by a single 9-volt battery. Access is usually provided via the flip-top preamp housing, allowing for quick battery changes without removing the entire unit.
Does this unit require professional installation?: Professional installation is highly recommended because it requires cutting a hole in the side of the guitar and precisely fitting the under-saddle pickup. Incorrect installation can damage the instrument or result in uneven string volume.
What does the Phase switch do?: The Phase switch reverses the polarity of the signal. This is useful for improving bass response at low volumes and can help cancel out feedback when playing at higher volumes near an amplifier.
How does the 'Brilliance' slider affect the sound?: The Brilliance control targets the very high frequencies of the guitar's output. Increasing it adds 'air' and shimmer to the sound, which can help the guitar cut through a dense mix of other instruments.
Can I use this preamp with a nylon-string guitar?: Yes, provided the bridge slot matches the narrow pickup width. The Prefix Plus-T is commonly used on both steel-string and nylon-string acoustic guitars to provide professional-grade amplification.
Is the Prefix Plus-T a quiet preamp?: Fishman describes the electronics as 'ultra-quiet.' This means the internal circuitry is designed to minimize the self-noise (hiss) often found in cheaper onboard preamp systems.
How does this compare to a Behringer PP400?: The Behringer PP400 is a phono preamp for turntables, whereas the Prefix Plus-T is an onboard acoustic guitar preamp. They serve entirely different purposes and are not interchangeable in a signal chain.