FAQ - Classic

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

How hard is it to install?
How big is the module?
Where do I connect the Pickup Ground wire?
Why is the pickup ground separated from the jack ground?
What if I have Active pickups?
How do I install a pickup coil switch?
How do I ground the pots?
Why does it pop when I plug in the cable to the bass with the amp power on?
How is the module mounted?
What if I don't know anything about bass guitar wiring?
What type of wire is used?
Where is a wiring diagram?
What types of pots are used?
Do you provide knobs?
What are the frequency responses of the tone controls?
What is heat shrink and why would you include any with my preamp?
What if my bass control holes are 0.4" diameter?

How hard is it to install?: We have an example of an installation under Support/Documents or follow this 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 drawing .pdf.

Where do I connect my Pickup Ground Wire?: Pickups have at least 2 wires, call them Hot and Common. The pickup Common(s) must be connected to the module wire that is Green stripe on White; it has one end free for the attachment. If you have two pickups, they join together with the module wire. (Hot wires attach to other module wires: Black stripe on White gets attached to the Bridge or a Single pickup; Blue stripe on White goes to the Neck pickup wire.)

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.
What if I have Active pickups?: Insert a coupling capacitor in between the pickup and the preamp. We supply optional metal film capacitors which can be purchased when you order your preamp and they are available from electronic component suppliers. The capacitor we recommend and offer is 330 nF. This puts a low end frequency limit on the signal of 4.8 Hz.

How do I install a pickup coil switch?: You can install a pickup coil selection switch in front of the preamp. Follow the wiring instructions from your pickup vendor but when they normally would connect to ground, with the Audere preamp you must connect them to the Green/White pickup common wire (see FAQ on 'Pickup Ground' above) .


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 looks interesting.
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 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 stripping tool.

Where is a wiring diagram?: PDF of Classic Wirng Diagram

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.

Do you provide knobs?: We optionally supply knobs with the preamp, you can select these when you order the preamp and we make it easy by sending you the right type. If you want fancier knobs then we'll add links to suppliers when we update a links page. Single controls have a 6 mm shaft size. Stacked controls have both a 6 mm and 8 mm shaft.

What are the frequency responses of tone controls?: 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 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 diameter?: 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.