We have often been asked...

Is it possible to retain the original sound of a J style bass?, but with a modern Active EQ? in the same preamp, along with no changes to my bass?

In response, we have created the J-TONE pre amp, replicating the authentic original passive wiring of the J style bass with a high spec Active EQ. It's designed as a direct drop-in replacement, including a place for the battery. It's easy to fit at home using basic tools, no soldering, no physical changes to the instrument*.

The Passive wiring is available as either the classic Volume / Volume / Tone, or for those who prefer a master volume - Volume / Blend / Tone. Plug-in tone caps allow additional fine tuning of the passive tone control.

The Active EQ is simplicity itself, incorporating highly responsive bass and treble controls, taken from our new high end UNI-PRE system. Internal edge wheels allow individual custom voicing for both the bass and treble control spectrums. Instrument qualities can be enhanced in conjunction with tone-shaping to match playing styles.

Details

The J-Tone is a new on board preamp with a fully passive signal path and a high spec professional active preamp. It is designed to fit directly into any jazz style bass without the need for invasive modification to the instrument. In passive mode, the original jazz style bass is fully maintained since the signal path is a replica of those in the original Jazz. The preamp comes in two versions:

Volume / Volume type allows control of each pickup individually.
Volume / Blend version allows the pickups balance to be set with the Blend, and a Master Volume for the overall output.

Summary of Features & Basic Spec

Classic Volume / Volume / Tone passive path version, replicating original J style wiring.
Volume / Blend / Tone version for those who prefer a master volume.
Push-Pull active/passive on Passive Tone.
Class A FET input stage for great sound quality, with master gain trim preset adjuster.
Highly responsive Bass and Treble control adjustments in active.
Frequency Wheels to set the width of the bass and treble spectrums individually.
Passive Tone is always operational, in both active and passive.
Passive Tone has plug-in tone cap to allow easy swapping of the cap value for different roll-off frequencies.
Bass control can be set as boost/cut or boost only, with an internal jumper link setting.
Screw terminals for all external connections - pickups and grounding, for easy installation.
Designed as drop-in replacement for standard J electronics with no physical changes to the instrument*.
Design allows 9V Battery to mount beneath the preamp in a standard J style bass.

Basic Response, Gain & EQ Spec

PASSIVE MODE: Neutral at response in accordance with passive control settings.
ACTIVE MODE: Neutral at response when Bass & Treble controls are set to their centre clicks.
GAIN TRIM: Internal Trimmer 0-12dBs setting overall gain of active circuit.
BASS CONTROL: +/- 18dBs Cut/Boost with internally adjustable shelf frequency 40–200Hz.
TREBLE CONTROL: +/- 18dBs Cut/Boost with internally adjustable shelf frequency 1kHz – 7.5kHz.

Note: * The J-Tone will fit in the majority of J style basses, but the routing width and depth of cavities does vary, so we can't guarantee it. It's important to check that a 9V battery drops into the cavity close to the jack, and that there's a depth of 32mm.

EASY TO FIT, NO ROUTING OR MODS TO MOST J STYLE BASSES.

A STANDARD PP3 BATTERY FITS UNDER THE PLATE IN THE STANDARD CAVITY IN MOST CASES.

John East J-TONE

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