The J-TONE consists of a Full Passive Path with Active Bass & Treble switchable in or bypass. This unit is designed to fit Standard J-Style Basses – 4 & 5 string instruments.

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.

SKU: j-tone Category:


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.

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.




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.


Watch Phil Mann getting acquainted with his brand new J Tone Bass Preamp at East Tone HQ

Operation Manual

What They Say

* ??It’s obvious to me that John is not only an amazing engineer but also an awesome bass enthusiast. The J Tone, like all of his products has been created from a bassists view point. It’s a musical product that allows the bassist to get the exact sounds that he/she needs from the instrument (quickly and easily). IMO if you want to give your bass a STEROID type boost, stick one of these ‘bad boys’ in. You won’t be disappointed ……… Forgot to mention it sounds fab in passive too. Paul – UK

* ??I?۪m over the moon with the J Tone I received today, it?۪s such a lovely addition to my bass. Thank you for your wonderful innovation. Daniel – UK

* ??The J-Tone preamp you supplied has elevated the sound from an already fine bass into a sonic realm that’s perfect for my needs. You’re doing great work, John, keep it up! Andrew – UK


Bass Musician’ magazine review

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