FAQ - Z-Mode & Misc...

How does it sound?
What makes it fundamentally different?
Why 3 Z-Modes?
Can I use a pickup coil selection switch?
Can I use it as an external box?
Can I use it with my wireless interface?
What pickups does it work with?
Does the preamp filter the tone?
Does it work with a Piezo saddle?
How do I know I will like it?

How does it sound?: Check it out on the Sound Clips page.

What makes it fundamentally different?: See the Z-Mode & String Vibrations page

Why 3 Z-Modes?: We can create more modes but 3 offers a good tradeoff between distinctive sounds and complexity of controls.
We also offer a 6 way rotary-type switch on the JZ6D.
There is more detail on each of the modes: High Z, Mid Z and Low Z under features, and for more on impedance control see the Technical Details page.

Can I use a pickup coil selection switch?: Yes - follow the instructions or wiring diagram that came from your pickup vendor but use the 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...

Can I use it as an external box?: No - unlike other electric bass guitar preamps we directly control the load on the pickups. If you had the traditional volume, tone controls etc. connected to the pickups then their impedance load would be affecting the pickups and the advantage of our technique would be limited. This is what makes our module different from most preamps which are only active tone control and cable buffer.

Our design is a fundamentally different concept and we often build systems without any tone control - actually most of my personal basses are setup this way. Like other on-board preamps, we offer the active tone control(s) and drive the cable with a low impedance buffer, but the real innovation and sound dynamic is in the Z control (see the Technical Details page).

Can I use it with my wireless interface?: Yes. Our design allows more of the fundamental vibration of the string to be sensed by the pickups, especially in the Low-Z mode, so you probably want to use a unit designed for the bass.
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What pickups does it work with?: To use our preamp, you must have Passive Pickups, meaning that the pickup does NOT have a semiconductor component in it (transistor, op-amp etc). Passive are the most common type of pickup but if you are uncertain about yours, check with the manufacturer or send us an email.

Does the preamp filter the tone?: This could be one of 3 questions:; 1) Is the increased low end in the Low Z (impedance) due to a bass boost? No, the pickup fundamentally provides a different output frequency spectrum when loaded differently.
2) Does the preamp offer frequency filtering? Yes, we offer EQ bands from 1 through 4 band tone controls and a 3 Band with switch-able mid range frequency selection.
3) Does the preamp filter the signal's response? Yes - all quality amplifiers should filter the signal at both ends of the frequency spectrum. On the low end we filter the signal due to the output capacitance coupling when combined with the input impedance of the bass amplifier to eliminate signals DC. This filter will have a flat frequency response at or below 10 Hz with even a relatively low input impedance amplifier (10K). For most amplifiers the low limit would be around 1 Hz. Then, on the high side a well designed amplifier will always limit the frequency response. We set a 12 db roll off starting at 15 KHz. This will reduce non-useful high frequency hiss. This filter is set high enough that most tweeters in bass speaker cabinets already have a reduced frequency response.

Does it work with a Piezo saddle?: To use the preamp with a Piezo sensor, you need an external high impedance buffer connected directly to the Piezo sensor. Since we have buffered the magnetic pickup signals before the volume control(s) you can easily mix in the output from the Piezo buffer amplifier together with the magnetic pickup signals. The Piezo output will normally have its own volume control pot. We may offer an advanced Piezo interface in the future.

How do I know I will like it?: We offer a money back satisfaction guarantee - try it for 10 days - read the fine print on the Warranty page.