FAQ - Pickups

Why does using different pickups change the sound so much with this preamp?
How does using fewer windings change the sound?
How does the type of volume control setting change the sound?
How does the type of balance controls change the sound?
How many wires are typically used and what do they do?
What type of wire should be connected to the pickups?
Which is better series or parallel connected coils?
Can I use a pickup coil selection switch?
What is the effect of hand wound or scatter wound coils?
What effect does the different type of magnets create?

Why does using different pickups change the sound so much with this preamp?: The Audere preamp interacts with pickup's design more strongly than your traditional passive bass or other preamps because:

1) We have designed the Audere preamp systems to insure the maxim transparency/accuracy in the signal capture. To achieve this goal we have selected some uncommon structures like DC coupling the pickups to the preamp and at multiple points in the design have selected significantly more expensive components (often 10x typical) to insure that we are giving you the most accurate view of what is being captured by the pickups.

2) The different Z-Mode settings are changing the loading on the pickups which interacts with the design of the pickups. Variation in the pickup's design and how the pickup's magnetic field interacts with the string's vibration is what causes the sound change as the loading on the pickup is changing. The Z-Mode changes are more fundamental than the simple Eq variations which is typically available in preamps.

The Z-Mode switch makes it easy to extend your sonic palette, extracted new organic and useful sound from the pickups. Most players also appreciate the increased transparency and hearing the true nature of their music revealed. But if there is a weakness within the pickup system then the increased transparency will make this more self evident. However do not assume price of a pickup is directly related to quality. The Fender Squier line uses low cost pickups but the Duncan Designed Jazz pickups, for example, are really nice traditional jazz pickups.

How does using fewer windings change the sound?: Several pickup manufacturers have created pickups with a lower number of turns than a classic Fender type pickup. They often claim the advantage of this type of pickup design is more of the high frequencies are reproduced. This statement is correct for a passive bass but is not significant for a bass that contains a preamp. To understand why we will look at each case separately.

If the bass does not have a preamp then the pickup is the only energy source available to drive the capacitance of the cable. Above some frequency point the pickup will not have enough energy to drive the cable with a flat response; the combination of the pickup's internal capacitance and the cable's capacitance will start attenuating the signal level. The longer the cable, the more capacitance to be driven, the lower the frequency point where attenuation starts.

If a bass contains a preamp, it provides the energy to drive the cable. Which, for most pickups, plays a more significant role in determining the high frequency response and the attenuation point. Since the typical preamp uses a greater force to drive the cable capacitance, the frequency response of the system is not significantly impacted by the cable's capacitance.

Given the sound trade offs we prefer a pickup design with a standard to increased number of wire wraps.

How does the type of volume control setting change the sound?: Ignoring the obvious signal level...

In a passive bass, if the volume control's level is reduced then the high frequency response drops at an even greater rate. The control reduces the volume by dividing the signal which also increases the resistance, which in turn decreases the energy available to drive the cable, and limits the high frequency level the cable can be driven to.

In an active bass, the frequency at which the roll off starts may or may not be affected by the volume control level. It is common for manufacturers to put the volume control after the preamp electronics. In that position the volume control will limit the current which is available to drive the capacitance of the cable when the volume level is reduced.

Audere preamps use a buffer after the volume control(s) except when the user selects a system with an active/passive switch in the Pro Z preamps series. This removes the impact of the volume controls resistance variation.

How does the type of balance controls change the sound of pickups?: Ignoring the obvious mixing of the 2 pickup signals...

In a passive bass, the style of balance pot will also change the frequency at which the signal attenuation starts.
The most common passive balance pots are made with 2 audio taper pots - 1 right handed - 1 left handed. In the center both pots are attenuating the signal mixed together. The effective resistance in between the pickups and the output is set by the combination of these 2 pots resistances. This combined resistance will also reduce the frequency at which the passive response will roll off as it attempts to drive the cable (see above).
With a 100% 'ON' balance pot - the 2 pots have a linear taper and they are both full on when the pot is at center. One is still right handed and the 2nd is left handed. In the center both pots are wiring the 2 pickups together and there is no extra source resistance to reduce the roll off frequency. This is why some players prefer this type of balance control on their passive basses.

In the Audere preamps, we buffer both pickups independently before they are mixed together; this is true whether it has 2 volume controls or a balance control. Either way you will get the full natural response of the pickups.

How many wires are typically used and what do they do?: Ideally for a single coil pickup you will have 3 wires
   Hot - black,
   Common - white,
   Shield -bare.
A dual coil would add
   Hot - red
   Common - green
Often the shield wire is deleted and some manufacturers use different color schemes.

What type of wire should be connected to the pickups?: The wire type is not especially critical in this application since the resistance is not significant. The capacitance and inductance is limited by the short wire run length. The best wiring would include a conductive shield with a drain wire. The insulation should not easily "cold flow" (move around under pressure) since it is typically located under the pickups and you can not see what is pushing against the insulation. Any high quality multi-strand wire can be used. I would recommend a wire size around 24 AWG for easy of handling.

Which is better Series or Parallel connected coils?: In a passive bass putting the 2 coils in Parallel will create more drive current so you will get more of the high frequency response at the end of the cable but this also changes the response of the pickup to the strings vibrations. Even with a passive bass most players seem to prefer the sound of Series connected coils with a short cable.

In active basses the Series combination is most often selected.

When using an Audere preamp the Series connection will provide a larger sound difference when switching from the High Z-Mode to the Mid Z-Mode. If you want the maximum flexibility then you might consider adding a switch (next topic) to vary the pickup's coil wiring.

Can I use a pickup coil selection switch?: Yes - follow the instructions or wiring diagram that came from your pickup manufacturer but use the Audere white wire with the green stripe in place of all ground connections. Do not connect the green stripped wire to ground! We recommend a single/series/parallel switch which can be implemented with a DPDT On-On-On type of switch. Having a separate switch for each pickup is even better...
With the Audere preamp - the Low Z-Mode output level will change as you change from series to parallel mode (the degree of change will depend on your pickups) . The parallel mode will be louder in Low Z-Mode so be sure to consider all of your pickup coil combinations when you adjust the Low Z-Mode gain during installation.

What is the effect of hand wound or scatter wound coils?: This is a complex subject.

The hand wound coils when compared to uniform machine wound coils can have a different response across the frequency band depending on what path around the coil the wire actual took during the winding process.

When combined with an Audere preamp you will hear more subtle response effects between different pickups than you will with either a passive bass or with most other preamps.

The High Z-Mode peaked frequency will be reduced by the hand winding assuming you are comparing it to a coil with an equal number of turns which is uniformly machine wound.

What effect does the different type of magnets create?: This is a very complex subject... Typical differences include:
1) How strong the output is, which may interact with a non-linear amplifier in the signal path like any tube stage.
2) The damping rate of the strings' vibrations, especially in the Low Z-Mode. Stronger magnets will dampen the high frequency vibrations faster.
3) Any non uniformity to the magnets shape (like a sharp edge around the pole pieces) will create a non-uniform magnetic field for the string's motion path to interact with.
4) The Length and Diameter of the magnets will effect the shape of the magnetic field in the area of the strings.
There are lots of other differences but these are some of the larger ones.