5 Z-mode preamp for Jazz Style Basses with the
Jack on the Body Side
The JZ5D preamp series have been upgraded to the Pro JZ6D Preamps.
The JZ5D models are an expansion to our popular JZ3 preamps. New Z-mode
combinations are offered by replacing the 3 way micro toggle switch
with a 5 way rotary switch. The JZ3 preamp allows both pickups to be
put in High, Mid, and Low Z-Modes. The JZ5D extends these 3 choices;
the 1st new configuration offered is High Z-Mode on the bridge pickup
combined with a less bright Low Z-Mode on the neck pickup. The 2nd
additional new configuration offers High Z-Mode on the bridge pickup
combined with a "standard" mid Z-Mode on the neck. These
new combined Z-Mode selections extend the
palette of interesting sounds available to the player especially
as he pans between the 2 pickups.
The JZ5D preamps come completely outfitted to make installation simple
and are designed to replace a standard Jazz Bass style control plate
with a side mounted cord jack. The battery connections are soldered
together but not insulated as shown in the 2nd picture below. This
is to make installation easier for basses with a rear mounted battery
box.
To make the JZ5D preamps as affordable as possible, we offer the same
control options as the JZ3.
- Volume, Mid/Balance stack, Treble/Bass stack, Z-mode switch & LED
meter (shown in photo) or
- Volume, Volume, Treble/Bass stack, Z-mode switch, & LED meter
(not shown)

Both versions use the same high quality design and components as our
JZ3 and our 3ZB configurable preamps and have the LED battery level
indicator. Most important, they both feature our Z-Mode
Impedance level control, delivering 5 selectable bass voices with
clarity and definition.
Further on you'll find more information about these additional features:
- Low Z gain adjustment with single turn pots and
- High Z Capacitors that are socketed so that you have the option
of changing their value, which optimizes the Frequency peak location.
Installation is easy: remove your old plate and side
jack, insert the new switched jack into the side of the bass, insert
the pickup wires into the green connector and tighten the screws, attach
the ground wire to your bridge & cavity ground wires with a crimp
connection, insulate the crimp connection, drop the battery and plate
into the cavity (take care here to be sure the battery is positioned
in the board cut-out and no wires are trapped) then screw in the 3
plate screws. In some installations you will need to solder connections
to the batteries in your existing battery box. For more info read the
Installation Instructions.

Plate Mounted Jack? If your jack is
in the plate please see our JZ3 Preamp.
Standard Sized Cavities
The current American Fender Jazz Bass has a cavity that measures approximately:
1.19"wide at the top (some cavity narrow slightly at the jack
end), 1.27" deep, and 5.17" long.
Most jazz style basses including current Fenders made in Mexico and
Japan have this same cavity size. A few other brands may be different
and some older Fender basses, especially vintage models, may vary from
these dimensions.
When you check the size of your cavity, our preamp needs cavity dimensions
of: 1.1" wide, 1.2" deep and 4.8" long.
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 standard configuration for most active basses includes volume
and balance controls. If you like this configuration, we offer this
with Treble, Mid and Bass tone controls. You will notice our balance
control is actively buffered so it will be very smooth in its operation
as you pan between the pickups.
Tone Controls
In the JZ5D 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 of the tone control pots have center detents where the response
is flat.
Battery
The preamp uses and ships with a standard 9 volt battery. A high quality
battery should last just over 300 hours in this preamp.
All of our preamps feature a very useful LED battery power meter.
The meter operates for a few seconds when the cable is first plugged
in to let you know about the batteries status.
Flexibility