FAQ - JZ3/JZ3D/JZ6D

This FAQ is for the 1st generation of the Jazz Series which has been upgraded Jazz Preamps

Most common installation problems
How hard is it to install?
What is the difference between JZ3 and JZ3D?
What is the difference between JZ3 and JZ5D?
What is the difference between JZ3D and JZ5D?
My JZ3D or JZ5D has 2 wires which are not insulated?
How big is it?
Can I connect my Pickup Ground wire to the Cavity Ground?
What if my pickups do not hum-cancel when both pickups are used?
Why does it pop when I plug in the cable to the bass with the amp power on?
Why is there no sound for the first few seconds after power up?
What types of pots are used?
What kind of finish can I get?
Can I change the direction of the Z-Mode switch?
Do I hear more static noise in the High-Z setting?
What are the 2 adjustment pots on the module?
What are the 2 indented dots on the adjustment pots?
What is the short yellow wire for?
How can I adjust my peak frequency response in High Z-Mode?
What if High Z-Mode sounds exactly like Mid Z-Mode?
What is heat shrink and why would you include any with my preamp?
How long will the battery last?
My LED Battery Meter Flashes 10 times?
Can I run this preamp on 18 volts?
I have a vintage ...?

Most common installation problems: • Trapping a wire or not getting the battery in the right place (do not force fit during installation)
• Connecting the pickup common to the ground (causes DISTORTION and drains battery)
• Not connecting the pickup common to the connector (causes DISTORTION)
• Not connecting the ground wire to the bridge (causes increased HUM while playing)
How hard is it to install?: It is easy to install - no soldering is required. You'll need a small Phillips screw driver and pliers, a heat source (a match can be used with care...) to reduce the heat shrink insulation and you may need to strip back the insulation on your pickup and ground wires. For more info read the Installation Instructions.

Differences between JZ3 and JZ3D?: The JZ3 fits into a standard Jazz bass with the jack on the cavity.
The JZ3D fits into a Jazz bass with the jack on the side. It features an additional passive type tone control. It also is shipped with 2 exposed solder joints.

Differences between JZ3 and JZ5D?: The JZ3 fits into a standard Jazz bass with the jack on the cavity. It features 3 Z-Modes on a toggle switch.
The JZ5D fits into a Jazz bass with the jack on the side. It features 5 Z-Modes on a rotary switch. It also is shipped with 2 exposed solder joints (see next question).


Differences between JZ3D and JZ5D?: The JZ3D features 3 Z-Modes on a toggle switch and an additional passive type tone control.
The JZ5D features 5 Z-Modes on a rotary switch.


My JZ3D or JZ5D has 2 wires which are not insulated?: The JZ3D and JZ5D is shipped with insulation on the battery wires which have not been reduced in size. Most J-Deluxe customers already have a battery box in the back of their bass. They will unsoldered the 2 exposed joints and connect the wires to their existing battery box. If you do not have an external battery box - simply heat the heat shrink to insulate the existing solder joint.

How big is it?: The board and battery that extend into the bass require a cavity size of 1.1" wide, 1.2" deep and 4.8" long.
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Can I connect my Pickup Ground wires to the Cavity Ground?: Pickups can have 2 or 3 wires.
• Every pickup has at least 2 wires, we call them Hot and Common. Common must be connected to our board at the screw connector as shown in the installation instructions.
• If you have a 3rd wire and it is a braided shield that wraps around the pair of wires, this is a Ground wire and can be connected to the Cavity Ground.

What if my pickups do not hum-cancel when both pickups are used?: The 2 pickups should be reversed wound with reverse polarity (RWRP). You need to invert (swap) the hot and common wires for just one of the pickups then they should hum-cancel.

Why does it pop when I plug in the cable to the bass with the amp power on?: Due to the standard power switching used for the battery connection the battery is connected to the input of the guitar cable during the time the cable is sliding into the jack. Most people develop a habit of partially pulling out the other end of the cable before inserting the connector into the bass jack. Some people use a guitar cable with an integrated disconnect switch.

Why is there no sound for the few seconds when the unit first powers up?: We mute the sound during the battery test time. The hardware is initializing the power supply level and checking the switch positions to set the Z- mode etc.
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What types of pots are used?: The pots we use are high end audio grade with low noise metal film resistance elements (often called industrial controls). The volume pots have an audio taper and active tone controls have a linear taper. The tone controls have a center detent which yields a flat response.

What kind of finish can I get?: These preamps comes in chrome only.
You can remove the knobs and replace them with your own.
You can remove the preamp from the plate and install it on your own plate also but you will need to drill 1 hole for the LED and a 2nd hole for the switch if you have a JZ3 preamp.

Can I change the direction of the Z-Mode switch?: On the JZ3 preamps, you can always flip the switch 180 degrees and probably +/-90 depending on your cavity routing.
With the JZ5D preamps, you will not have enough room to rotate the switch in the cavity.

Do I hear more static noise in the High-Z setting?: Yep - This is true for any comparable preamp. It is a physics problem - a high input impedance amplifier will have more noise due to increased Shot Noise in the input resistor. Excess noise normally increases in higher Ohm resistors. Also the pickups with this loading will pick up more voltage noise from various sources in the environment. While we can not beat the fundamentals of physics - the circuit design and parts were selected to reduce the noise level as much as is possible given the impedance tradeoffs. Increased shielding of the pickup cavities can help reduce the noise in all modes.

What are the 2 adjustment pots on the module?: Those are the Low Z-mode gain adjustment. They adjust the loudness of the pickups when in Low Z-mode (more information is on the Low Z page).

What are the 2 indented dots on the adjustment pots?: Those are the markers to tell you how far the pot is rotated. An imaginary line splitting the 2 dots and the center of the pot will indicate the position of the pot knob.

What is the short yellow wire for?: To start with the wire is not broken - it does not connect to anything. This is an electrical connection we use for testing when we build the preamp. We may also use it for upgrades in the future. It should be electrically insulated and left attached to the circuit board.

How can I change my peak frequency response in High Z-Mode?: Many players prefer the resonant frequency in the 2k to 5k range which is the mid to upper range of a female vocal. The factors that determine the location of the peak frequency are explained in more detail in the High Z feature section, but capacitance is one of them and that can be changed by changing the capacitor value. The circuit board has two sockets one for each pickup; the capacitors are inserted manually and can be pulled out and replaced. The sockets are a very tight fit so use care if you choose to do this. We sell an accessory kit of 10 values which will plug into the sockets. For our caps, the writing on them indicates the capacitance in pF. The code is 3 digits where the last digit is the power of 10 to multiple times the first 2 digits. So 331 becomes 33 x 10^1 which is 330 pF (standard bridge pickup cap).

What if High Z-Mode sounds exactly like Mid Z-Mode?: If your pickup is a non-traditional design with a low amount of coil inductance and a low amount of capacitance, then the High Z-Mode resonant frequency could be located at a frequency too high for your speaker system to respond to. You can change the capacitor value on the circuit board; this will bring the resonant frequency into a range where you can hear it. For more info read the Installation Instructions.

What is heat shrink and why would you include any with my preamp?: Heat shrink tubing is a plastic tube which is used to insulate wiring. The tubing shrinks or reduces its diameter when you heat it. You can shrink it with a hot air source (a match can be used with care). Just be careful you do not apply too much heat to the tube or other parts on your bass. We supply you with a few pieces so you can insulate the crimp connection for the ground wires.

How long will the battery last?: A quality battery will last just over 300 hours of playing time with the preamp. More information about battery power is located in the Battery Power FAQ.

My LED Battery Meter Flashes 10 times in 5 sec?: You have either a discharged battery (voltage too low time) or
Your pickup common is connected to ground. In a new instillation (especially common on Fender Geddy Lee Basses) the pickup vendor or bass manufacture will often solder together the pickup common wire to the pickup wiring shield. When installing the Audere preamp: Unsolder - or cut off the end of the wire to separate the 2 connections. The pickup common (usually the wire with small writing on it) is inserted in to the green connector on the front of the preamp. The shield drain wire is connected to the black cavity ground wires which are connected to the Gray/White wire coming off the Audere preamp jack.

Can I run this preamp on 18 volts?: If you have an external battery compartment then you can run the preamp on 18 volts. Your battery life will be very long. Simply remove the existing battery clip and attach your wires to the leads from your battery compartment. Red is the positive voltage and black is the negative of course.

I have a vintage ...?: If you have a vintage bass then we recommend pulling the old control plate as a single unit. You will want to reinstall the old plate just before you sell the bass. Since the old control plate will be intact this is much easier to do... For the curious there is at least one previously original 62 Fender Jazz body which now has an Audere JZ3 preamp installed in it.