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PZ-Pre™ USING & APPLICATIONS

The following page discusses how to use the PZ-Pre. You will find that it is perfectly suitable for guitar, bass, upright, bluegrass instruments and all types of orchestral instruments. For complete details on how to use the PZ-Pre, feel free to download the manual by clicking on the icon at left.

Making connections

Before connecting the PZ-Pre, make sure all levels are turned down or equipment turned off. This will help protect more sensitive components such as tweeters from being damaged due to turn-on and plug-in transients. There is no power switch on the PZ-Pre, simply plug in the 15VDC power supply to turn it on.

There are two inputs on the PZ-Pre with separate level controls. These may be used independently for two instruments or combined using the blend (mix) function. The inputs are equally suitable for piezo transducers, magnetic pickups or buffered sources such as guitars equipped with built-in preamps. These feed a tuner output which is always on.

There are also three outputs: The first is a ¼" hi-Z output designed for the musician's personal stage amplifier. The second is a low-Z output to feed the on-stage monitor system. Both of these outputs are fed after the EQ, filters and effects that may be added to create the sound on stage. The third output is a low-Z pre-EQ out designed to feed the PA system. This output is purposely left 'dry' in order to send a clean, unprocessed signal to the FOH engineer. This enables him to add reverb or echo to suit the room or simply leave it dry if the room is already too lively.

Setting the inputs to match the source

Before you get started, it is best to determine what kind of instrument or pickup you will be using so that you can optimize the input settings to match. This not only will result in better sound, but will help reduce distortion and maximize signal-to-noise.

  • Using piezo transducers
    Piezos are contact type pickups that either attach to the body or bridge of the instrument or fit under the bridge. These are common with acoustic guitars and orchestral instruments such as upright bass or violin and are also regularly used with bluegrass instruments, classical guitars and so on. Piezos produce a very low output that requires adding a preamp between the pickup and the stage amp or mixing console. The PZ-Pre is equipped with a special PZB booster on each input that enables you to connect from the pickup directly without a preamp. Simply push the recessed 'set & forget' switches inward to activate.
  • Using magnetic pickups
    Many acoustic guitarists use a sound-hole pickup. These are usually magnetic pickups that produce a fairly loud signal. For these, disengage the PZB by making sure the switch is pushed in the outward position. If you are using an electric bass, the same applies.
  • Using buffered sources
    Some acoustic instruments are equipped with battery powered preamps that are either built inside the cavity or are in the form of an external preamp. These buffered sources are perfectly suitable for use with the PZ-Pre. Because they are pre-amplified (buffered) – they do not need the PZB's extra boost, so you will want to turn this off by making sure the booster is in the out position.
  • Switching between the two inputs
    Selecting between input-1 and input-2 is done by depressing the input select TOGGLE footswitch. As you hit the switch, the inputs will toggle as will the associated LED indicator lights. Switching is silent making it very convenient for on-stage use.
  • Blending the two inputs
    The PZ-Pre may also be configured for those who wish to combine two inputs such as blending a magnetic pickup with a piezo together. There may also be situations where having both channels on at the same time may be required. Simply set the recessed 'set & forget' blend switch on the side panel to the inward position and then use the two volume controls to set the balance between the two sources.

Adjusting the filters and tone controls

There are several tone controls and filters on the PZ-Pre that all work together to create the sound. In other words, reducing deep bass by activating the high pass filter can still be affected by increasing the bass using the tone control. Always try to keep EQ'ing to a minimum. This retains a more natural sound and often makes it easier to control feedback.

  • High-pass filter
    Acoustic instruments are notorious for on-stage feedback and runaway resonance. A three position high-pass filter is used to cut the bass and allow the high frequencies to pass. For bigger instruments like acoustic guitars or upright, try setting the filter in the medium position. For smaller instruments like mandolin or violin, set the filter to the bottom for maximum cut. This will eliminate excessive bass which is not needed.
  • Notch filter
    Depending on the size, each instrument will have a different resonant frequency. These are generally lower on larger instruments and higher on smaller ones. If you encounter a problem frequency, the Notch Filter can be used to smooth it out. Simply engage the filter and slowly rotate the notch frequency control until you hear the problem subside. Increase the notch to the more radical filter if needed.
  • Semi-parametric EQ:
    Once again, since all instruments are different, the PZ-Pre's tone shaping has been designed to address the various characters with a 3-band EQ and semi-parametric mid range control. This simple yet highly effective EQ lets you dial in the sweet-spot for the most natural and dynamic tone. Start with all knobs set to the 12 o'clock position. Be careful! These controls are very powerful. Because human hearing is most sensitive in the mid range, you will naturally want to pull some of these frequencies out. Try to resist! All of the energy is in the mid range so if you take it out, you will not be heard! Start by boosting the mid range to 3 o'clock and listen to the various frequencies as you sweep the band. When you hear a tone that sounds excessive; stop. Then dial the mid control back from 12 o'clock counter-clockwise. Try adding a bit of top end, maybe a touch of bass... experiment!
  • 180° Phase reverse:
    Technically speaking, this is actually a polarity reverse switch that lets you toggle the polarity of the signal before it reaches your on-stage amp and the post EQ XLR output. It is used to help reduce feedback on stage when the physical location of the performer, the monitors and the stage amp coincide to cause a feedback hot-spot. There is also a second 'set & forget' polarity reverse switch that affects the post XLR output on the rear panel. This can be used to counter the effect of the polarity reverse on the top panel to see which position works best.

Activating the performance attributes

The PZ-Pre is equipped with a number of features that are designed to enhance the performance aspects of playing a live gig. This includes a footswitch for quick on-stage instrument changes, a power booster for solos, an effects loop to add sonic textures to the performance and a mute switch for quiet on-stage tuning.

  • Selecting instruments
    The footswitch on the right lets you toggle between the two instruments with a simple foot stomp. This enables the artist to reach over, pick up another instrument and simply hit the footswitch to toggle, presenting a more professional appearance on stage.
  • Power Booster
    The PZ-Pre is equipped with a fully variable power booster for soloing. It is engaged using the center footswitch. Once engaged, it is used to add extra output to accentuate the instrument during a musical passage. A three position switch lets you assign the footswitch to also add effects.
  • Effects send & receive loop
    Pedals can be noisy. By inserting them in a loop, you can activate them when needed, and then take them out of the signal path when not in use. Separate send & return ¼" jacks make connection to pedals easy. A three position switch lets you assign the power booster footswitch so that it activates the booster, the effects-loop or both. Alternatively, you can set the loop to remain on all the time and control the effects with their own footswitches.
  • Mute and tuner out
    Depressing the left side mute footswitch instantly silences all of the outputs except the tuner out for quiet on-stage tuning. The 'always on' tuner output is separately buffered so that it does not load the pickup or allow tuner clocking circuit to cause noise.

Sending the signal out

The PZ-Pre is equipped with four outputs: A ¼" unbalanced tuner out that is always on, a ¼" unbalanced guitar amp output for your personal on-stage setup, and two balanced XLR outs to feed the monitors and the PA. The tuner out is discussed above.

  • Stage amp output
    This is an unbalanced output that is designed to drive an on-stage amplifier. It is buffered. This means that inside the PZ-Pre, we amplify the instrument signal so that it can be properly managed. Once the signal is buffered, it enables you to run longer cables without being as sensitive to noise.
  • Pre EQ direct box out
    This low-Z balanced XLR output captures the signal before the filters, EQ and effects. The idea here is to allow the sound engineer to employ the clean direct signal from the instrument and mix it with the band and the room acoustics before the artist messes around with the tone. For instance if the engineer finds that the guitar is muddy, he may want to reduce bass. But if the musician onstage wants more bass in his monitors, they are conflicting. This direct output solves the problem.
  • Post EQ direct box out
    If you are using on-stage monitors, the post EQ direct out lets you send your processed signal to the monitors via the low-Z balanced XLR out. This lets you shape your tone to suit your playing without affecting the signal going to the front of house. If you are in a smaller venue that does not have an engineer, you can also use this output to send your mix to the PA system.
  • Ground Lift switch
    To help eliminate the hum and buzz caused by ground loops, the PZ-Pre is equipped with a 'set & forget' ground lift switch. When pushed inward, it lifts the pin-1 ground on both the pre-EQ and post EQ XLR outs. Lifting the ground is usually only required when using an on-stage amp.