Technical Info

More technical info about the JZ preamps and it's parts and operation are below.
A 2nd good place for info is in the FAQ info.

Volume Controls

The standard knob configuration for a passive Jazz Bass is volume, volume, and a treble roll off. If you like having separate volume controls for each pickup then we offer separate volumes with Treble and Bass active tone controls. The advantage of seperate volume contols is how they mix when one pickup is favored. If you only want a little of the 2nd pickup then you will get more control due to the log mixing of a vol vol setup.

The standard configuration for most active basses includes volume and balance controls. Some players like the single volume control as it is easier to adjust the volume without effecting the pickup ratios. If you like this configuration then we offer this with Treble, Mid and Bass tone controls and the simpler Treble and Bass only.

In either configuration you will notice, our balance control is actively buffered so it will be very smooth in it's operation as you pan between the pickups.

More info - JZ Volume Controls

Tone Controls

In the JZ3 product you get either a 2 or 3 band tone control depending on configuration

2 band tone controls:
Bass is shelving +/- 13 dB at 100 Hz
Treble is shelving +/- 14.5 dB at 2.5 KHz

3 band tone controls:
Bass is shelving +/- 12 dB at 80 Hz
Mid is wide bandwidth +/- 10 dB at 470 Hz
Treble is shelving +/- 10 dB at 3.7 KHz

All the tone control pots are centered de-tented where the response is flat.
More info - JZ Active Tone Controls

Battery

The preamp operations off a standard 9 volt battery. A high quality battery should last just over 250 hours in this preamp. We ship a battery with the preamp. More info - Battery FAQ

All of our preamps feature a very useful LED battery power meter. The meter operates when the cable is first plugged in to let you know about the batteries status. More info - JZ Battery Meter

Flexibility

Replaceable capacitors - Pickups vary in their signal response and most have a high frequency peak when loaded with a high impedance (you can read about it on our High Z page). The JZ3 allows you to change the location of that peak in High Z-mode by changing the amount of capacitance loading the pickup in the circuit, independently for each pickup. Each pickup channel has a socketed capacitor that can be changed, which changes the location of the peak frequency. You can see a bridge cap in the picture on the right. Optimized for stock US Fender Jazz pickups, JZ preamps come with 660 pF (encoded as 681) loading the neck pickup and 330 pF (331) loading the bridge pickup. To make changing your pickup's high frequency peak location we offer a kit of 10 cap values as an option.

Gain adjustment - In the Low Z Mode, the signal response of pickup changes 10:1 depending on how the pickups were constructed. The picture to the right shows a gain adjustment for the Low Z-Mode. If you want more gain, turn the gain adjustment for that pickup clockwise. If less gain is required turn counter clockwise. It is a relative gain control - it does not affect the frequency response of the pickup but due to the way humans hear we need lots of volume or sound pressure level to hear low notes. So adjusting the gain up will make your bass appear to be getting lower when actually it is just making the existing lower frequencies more audible. This is why this adjustment is for Low Z only. Stock US Fender Jazz pickups have the correct gain when the control is set to about 9:30 and this is how units are shipped.

Already Changed Out Your Pickups?

Our technology works great with all of the common upgrade pickups except active EMG pickups. Common customer replacement pickups we see include Nordstrand, Bartolini, Fralin, Basslines, DiMarzio and various forms of the Fender custom shop pickups.

NOTE: To use our preamp, you must have PASSIVE PICKUPS, meaning that the pickup does NOT have a semiconductor component in it (transistor, op-amp etc). If you are uncertain about your pickups, check with the manufacturer or send Sales an email

There are additional details on the controls and installation in the FAQs.

JZ3 Configurations, Pricing and Ordering
JZ3D Configurations, Pricing and Ordering
JZ6D Configurations, Pricing and Ordering

Fender Jazz Bass is a trademark of Fender Musical Instruments Corporation and Audere Audio has no affiliation with them. No surprise here...