J-Tone Preamp

A Review of the John East J-Tone Preamp  for J Style Basses

In our little universe, it doesn’t get much more iconic than the Fender Jazz Bass.  Since Leo Fender invented the dual pickup Fender Jazz bass in 1960, a relatively small amount of improvements or modifications have been made to the archetypal design.  It still has the 34” scale, it still has the pair of single coil pickups in the “standard locations”, the same pickguard shape and metal control plate and the passive volume/volume/tone control layout.  Although construction methods and manufacturing techniques have changed, along with things like neck profiles and body contouring, the basic design has stood the test of time.  One of a few things that have changed greatly over the years is the technology around electronics, which has had a huge impact on what can be considered the “Fender Jazz Bass tone family tree”.  The diaspora of Fender Jazz Bass tone has exploded with the advent of new technologies and ideas around pickups and electronics.  In recent years, there have emerged a number of active electronics designed specifically for Jazz Basses, and one of the more popular companies offering such products is UK based maker/designer of onboard bass preamps John East, of East UK.

Many may already be familiar with the popular East preamps, including his incredibly powerful and feature-packed J-Retro bass preamps, which is designed to fit inside the existing cavity of a Fender Jazz Bass, including 9v battery,requiring no routing or modifications to the body. The J-Retro was probably the firstcomplete drop-in EQ on a J plate, first released in 1998.

With all of the bells and whistles of the J-Retro’s feature set,  John has recently launched a new preamp offering for Jazz Bass players seeking to retain the original sound and feel of their passive instrument, but with the addition of transparent but powerful active EQ:  the J-Tone preamp.  Like the J-Retro, it is mounted to a Jazz Bass control plate and requires no modification or routing to an existing bass.   It also doesn’t require soldering skills (thank God, I shouldn’t be legally allowed to own a soldering iron), as all the connections are made via solderless screw terminals.

The J-tone is geared for players who like simple, usable EQ, and want to keep the simple passive vibe and sound of their instrument.

It can be ordered with dual volume controls, like a passive Jazz Bass, or a stacked volume/blend knob for those who prefer that layout.  Despite its relative simplicity, it has a whole lot going on under the hood.  The passive tone control works in both active and passive modes, and most notably, the bass and treble EQ controls offer what I consider to be the most unique, coolest and valuable aspect of the J-Tone preamp:  mounted to the electronics under the control plate, there are small thumbwheels which let you dial in the exact frequencies you desire for the bass and treble EQ knobs. This feature allows you to tailor your bass and treble EQ to either your preferred sound, the exact sort of EQ your bass requires, or EQ points optimized for your rigs frequency response. The bass control offers +/- 18db of boost and cut at anywhere between 40-200 Hz, while the treble EQ offers the same boost and cut in the 1kHz-7.5kHz range.   I absolutely love this feature and am quite familiar with it, having owned John’s flagship UNI-PRE, which also contains this feature.   In my opinion, it is such a smart and valuable function, and sets this preamp apart from its competitors in a substantial way.  As someone who tends to prefer a slightly deeper bass boost and a slightly higher/airier treble response, I have had great luck configuring the J-tone’s EQ to my obnoxiously picky liking.

While we’re on the subject of tweakability, The J-tone comes standard with a selection of “Plug In Tone Caps” which let you change the tonal response and taper of the unit’s passive tone control.

Not all passive tone controls are created equal, and the value of the capacitor determines how the high end is rolled off, and in some cases the overall tonal presentation of the preamp.   I asked John to shed some light on the plug in tone cap options and boy did he deliver: “Several Tone Caps have been included to allow players to set the Passive Tone roll-off frequency according to what works best for them. The higher the cap value, the lower the roll-off frequency, i.e. the more mellow or deeper the sound, when the tone control is fully backed off. The default cap fitted to a J-Tone is a 0.1uF (= 100nF) which is the deepest in terms of sound. It was used in the early P basses and is the stock value for East products. The 0.047uF (= 47nF) is less deep, often the stock value for Jazz basses, which used to be 0.05uF in the vintage instruments. The 0.033uF (= 33nF) is lighter still, very close to the value of 0.03uF, used for the bridge pickup in 62 Jazz basses, which had a tone control for each pickup. The 0.022uF (= 22nF) gives the least mellow tone, close to the vintage value of 0.02uF. This value does not seem to have been used in Fender basses, but a number of bass players like to use this cap for their passive tones.” In case you have glazed over, or your head is spinning, feel free to just do what I did:  try them all out and see which you prefer.   It wasn’t hard to hear the differences and my preference was pretty clear after just a little testing.

I was able to get the J-tone installed and up and running in about 10 minutes (loving those screw terminals for all connections, including the ground wires).

Before I screwed the plate down, I started playing through my rig and quickly honed in on my preferred bass and treble EQ settings with the small thumbwheels.   The preamp also has a trim pot for the overall output gain of the preamp, which I set to just slightly hotter than the passive volume level.   I installed the J-Tone in a couple of basses, including a 2012 MIA Fender Jazz and my personal 2016 Lakland Skyline DJ5 (“DJ-Tone” is the model name, due to the slightly different shape of the control plate that the preamp comes already installed on).  In both cases, it was very clear that the main goal of the design was achieved: retaining the sonic characteristics of a passive jazz bass with of the addition of flexible and powerful EQ. With the output gain trim pot set at unity gain, toggling between passive and active yielded almost no change in tone or response.   It doesn’t sound like an “active bass”, it truly sounds like a passive bass with some added flexibility.  The circuit adds very little noise, and although almost any active treble knob introduces some hiss, it was relatively, and admirably minimal with the J-Tone.

All in all, the J-Tone is a home run. It does everything it is supposed to do, without any foreseeable drawbacks or compromises.

As with everything East makes, the electronics appear to be of top shelf componentry, has a very high quality appearance, and the knobs and pots have a nice sturdy feel to them.   While some may prefer the more “kitchen sink” approach of the J-Retro and its slightly souped up tone, those looking to keep the inherent characteristics of their Jazz bass will likely be very pleased with the J-tone, as it seems to split the difference between “active” and “passive” beautifully.   As I really like the sound of my passive Lakland, I was very pleased that it still felt and sounded like a passive bass, but gave me more tonal flexibility for moments when I needed some more control than the passive layout provides.

While there are other “Jazz Bass Plate” preamps on the market, few if any can beat the quality of the J-Tone.

And none of them offer the type of tweakability that rewards players who willing to spend a little time with it with EQ that is just right for their preferences. More info and specs can be found in the J-Tone’s manual or on the product page on John East UK’s website.