FAQ - 3ZB
How hard is it
How big is the module?
Where do I connect the Pickup Ground wire?
Why is the pickup ground separated from the jack
How do I ground the pots?
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?
How is the module mounted?
What if I don't know anything about bass guitar
What type of wire is used?
Why so many wires?
What types of switches are used?
What types of pots are used?
What passive EQ controls do you offer?
Too many knobs - I ALWAYS set my X control to
the same position!
Do you provide knobs?
What colors of hardware can I get?
Do I hear more static noise in the High-Z setting?
What are the 4 adjustment pots on the module?
Does the active/passive switch bypass the
electronic circuit to make it a passive preamp?
What is the frequency response of the tone controls?
What can't I get my peak frequency response
higher in High Z-Mode?
Why does High Z-Mode sound exactly like Mid Z-Mode?
My bass has only 3 holes for controls - can I use
What if I don't want to drill a hole for the Battery
What is heat shrink and why would you include
any with my preamp?
What if my bass control holes are 0.4" diameter?
Some of my wires do not seem to go anywhere?
Can I wire up the pots and switches myself?
- How hard is it to
- We have an example of an installation under Support/Documents or
follow the Install
link. We recommend that you have experience with a soldering
iron and installing simple electronics. A Luthier or repair shop
can do it for you if you are uncertain. The Install example shows
how you can play test the unit early in the installation.
- How big is the module?
- The preamp is 2.0" by 1.0" by 0.55". This is the
same x by y size of a common 9 volt battery with a connector snapped
onto the top. The thickness is slightly thinner than a battery. Note:
there are a lot of wires which exit the top of the module. The drawing
for the module is in the mechanical
- Where do I connect my Pickup Ground
- Pickups have at least 2 wires, call them Hot and Common. The Common(s)
must be connected to the one wire that have one end free coming from
the Module that is Green stripe on White. If you have two pickups,
they join together with the module wire. (Hot wires also go to the
module, Black stripe on White goes the Bridge or a Single pickup,
Blue stripe on White goes to the Neck pickup.)
If you have a 3rd wire and it is a braided shield, this is a Ground
wire and can be connected to the Cavity Ground. Do NOT connect the
Common wires to the Cavity Ground. Doing so would increase the power
pull and cause distortion.
If you have 4 wires you may have two Hot wires for split coils. Check
with the pickup manufacturer on how to connect the 4 wire pickups
for parallel or series operation.
- Why is the pickup ground
separated from the jack ground?
- We developed a split power supply so we can DC couple the pickup
signal to the input of the amplifier. This allows us to move the
capacitive coupling to the output signal, which has a low impedance
drive source, instead of having it coupled at the pickup side which
is a high impedance signal. This provides a cleaner signal path.
- How do I ground the pots?
- The barrel of the pot is metal and is normally grounded by pressing
against the shielded cavity.
Traditionally in guitar electronics people soldered directly to the
back of pots. This was a poor idea for several reasons.
1) You need to use a very aggressive flux in the solder (acid core
was traditional). If the flux is not thoroughly cleaned off it will
reactivate when it gets humid and can corrode the metal and cause
the pot to fail.
2) You have to heat the heck out of the part. This often shifts the
resistance and permanently increases the noise of the resistance
element. Many pots have internal plastic parts that can be damaged
by this much heat.
- 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
(see the previous question) 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.
Planet Waves and others have cables with this feature. Neutrik has
a "Silent Plug" (NP2C) out that we haven't tried but it
- 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. The muted output is much better then listening
to the uncontrolled hardware startup.
- How is the module mounted?
- We provide durable double-sided sticky pads to go under the module,
secure but still removable.
- What if I don't know anything about wiring
an electric bass guitar?
- Installation is simple if you have experience with installing music
electronics. However, typical hand tools for soldering wire connections
and assembly are required. If you are uncertain about the installation
we recommend you have a guitar setup or repair technician or a Luthier
install it for you. The module and controls are all pre-wired to
make it easy to install; you will need to connect the pickup wires,
install the LED battery indicator, put the switches and pots into
the body mounting holes and attach your grounding to the jack.
- What type of wire is used?
- The wire is a Mil-grade thin Teflon jacket over 24 AWG with 19
sub-strands for high flexibility. Most of the wires have a base color
and a 2nd colored strip. The advantage of using Teflon is the insulation
can be very thin and will not burn back from high heat during soldering.
The disadvantage is it is harder to strip unless you use a very sharp
- Why so many wires?
- 18 base configurations, not including all the control options.
We could have eliminated any wires that you don't need for your specific
configuration but you might want to change the configuration later.
Instead, we keep all the preamp wiring intact so you can change your
tone or volume configuration in the future. Note: there are three
different base modules, 1 with no tone circuit, one with a circuit
for 1-3 bands, third is for 4 band control. The good news is we'll
pre-wire it for you.
- What types of switches are used?
- We use DPDT (on/off/on) for the Z-mode switch and QPDT (on/none/on)
for the preamp override switch. We tried several brands of switches
and selected Carling Technology switches which had good performance
at a reasonable cost.
- 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 pots
are small 9mm units which provide you with more vertical space to
stack the electronic module and battery. Our pots are all 100K ohms
with the volume pots having an audio taper
and active tone controls having a linear taper.
- What passive
EQ controls do you offer?
- We do offer a tone type control but our design intent for passive
mode is for use as a backup, not as the normal playing style. We
the Active/Passive page,
but to summarize - the advantage of our design is that it gives you
control of the impedance load on your pickups when in active mode.
In passive mode your pickups are affected by the downstream impedance
of the cable, external preamp, and any controls.
- Too many knobs - I ALWAYS set my X control
to the same position!
- If you want a quasi-fixed position control, for example, if you
always add/delete a little mid range, then we can wire up your unit
with a trimmer which is a small plastic part which stays hidden in
the control cavity. These controls are 25 turn adjustments so you
have a very accurate set point. The size of the adjuster is roughly
3/8" square by < 1/4" deep. This allows you to setup
the bass as desired then forget about that control. If you change
your mind later, then you can move the adjustment to a new setting.
The cost of this option is the same as a regular pot but you need
to put a note with the order to get it wired up this way, and include
an email address in case we have questions.
If you do not want one of the tone controls and you do not have room
to store the control in the body of the bass, you can remove the
control pot by cutting off the pot and insulating the wires. That
tone control section will default to a flat response.
- Do you provide knobs?
- We can supply knobs with the preamp but they are an optional item.
See the purchase menu under knobs. You can also use your own knobs.
a 6 mm
and 8 mm shaft. All knobs need a set screw to hold onto the shaft.
- What colors of hardware can I get?
- The switches are chrome and we provide a chrome, a black and a
gold washer/nut set so you can coordinate the look with your other
- 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
pickup 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. You can also really help reduce this
noise by Shielding the Pickup Cavities.
- What are the 4 adjustment pots on
- The two closest to the wires, the top edge of the module, are the
High Z-mode capacitance adjustments. These adjustments modify the
location of the resonant frequency peak of the pickups. More information
is available on the Impedance page
and on the High Z page.
The two on the lower edge of the module, away from the wires, are
the Low Z-mode gain adjustment. This adjusts the loudness of the
pickups in this mode, more information is on the Low
- Does the Active/Passive switch bypass
the electronic circuit to make it a passive preamp?
- Yes - in passive mode you could remove the battery and still play,
that is the ultimate test of whether a preamp is passive. Some people
use the term passive preamp to mean an active preamp without tone
controls, which is also an option with the Audere preamp. There is
a bit more info on choosing passive mode in
the Features section.
- What are the frequency responses of tone controls?
- For the passive style treble roll off
Treble rolls off starting at about 16k adjustable down
to 800 Hz
For the 3 band active module
Bass shelving ending at 240 Hz +/- 15 dB
Mid center 250, 500, 860 Hz +/- 10 dB
Treble shelving starting at 1.92 KHz +/- 15 dB
For the 4 band active module
Bass shelving ending at 172 Hz +/- 15 dB
Mid1 centered at 200 Hz (wide control) +/- 10 dB
Mid2 centered at 800 Hz +/- 10 dB
Treble shelving starting at 1.92 KHz +/- 15 dB.
- What can't I get my peak frequency
response higher 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 with the High
Z-Mode adjustment. The peak frequency location varies due to the
pickup's design and if your pickup is of the very low variety, then
there is a limit to what adjustments can be made external to the
pickup. The adjustment range provided by the preamp loads the pickup
from a small Capacitance, lower than any guitar cable / amp combination,
to a Capacitance larger than most 50' cables. If you can not get
the resonant peak location high enough (this would be a rare type
of pickup or unusually high peak location request) then you can change
out the pickup to one with a higher resonance location. In general
- look for a pickup with a ceramic magnetic or neodymium magnet as
these will have fewer turns of wire due to the strong magnets. If
the pickup has 4 wires brought out for the windings use Parallel
Hum canceling instead of Series Hum canceling.
- Why does High Z-Mode sound exactly like Mid
- 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 response too. Dial in more capacitance using the adjustment on
the preamp. This will bring the resonant frequency into a range where
you can hear it.
- My bass has only 3 holes for
controls - can I use this preamp?
- There are lots of options for what to do with your 3 holes. One
of the possible configurations is: 1st hole for a volume/volume;
2nd hole for the Z-Mode switch; and the 3rd hole for a Treble/Bass
- What if I don't want to drill
a hole for the Battery Indicator LED?
- The LED comes standard on all units. It is really nice to know
your battery level is cool before you step onto the stage. I would
recommend you allow us to wire it up and if you decide you do not
want it then cut off the LED and insulate the wires with the enclosed
heat shrink pieces. But it's your preference and if you add a note
to the order saying delete the LED then we will.
- 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. It comes in various types of plastic, sizes and shrinking ratios.
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 you bass. We supply you with a few pieces so you
can insulate your wiring if you need to.
- What if my bass control holes are 0.4" in
- We supply rubber rings to fit over the switches and single pots
to expand the diameter. This works well for most applications. If
you require a special sized spacer ring then most Luthiers could
help you out.
- Some of my wires do not
seem to go anywhere?
- On all 3ZB preamps there will be a varying number of extra wires
which do not go anywhere and are covered with heat shrink. The extra
wires allow you to change the configuration of the preamp in the
future. For example, if you decide to go from volume and volume controls
to a volume and balance setup - the extra wires allow the preamp
to be rewired to the new configuration. If you do not have space
for the wires or dislike the concept of having the extra wires attached
to your preamp then we can delete them. Just put a note in the comment
field with your order...
- Can I wire up the pots & switches myself?
- Sure, drop us a note with the order - but do you really want to?
Our background is building very high quality instruments and we have
a process in place to ensure that you'll receive a well built, fully
tested unit. If you want to shorten the wires or change your configuration
you can de-solder the wires and make your modifications. It will
be easier to change the connections one at a time.