Radial Engineering PZ-Pre User manual

Radial Engineering Ltd.
1588 Kebet Way, Port Coquitlam BC V3C 5M5
Tel: [phone] Fax: [phone]
email: [email protected]
www.tonebone.com
PZ-Pre™
Acoustic Instrument Preamp
User Guide

www.radialeng.com
Congratulations on your purchase of the Radial PZ-Pre, without
a doubt the most challenging pedal we have ever produced! Why?
Simply put, it is so jammed with features that it took us over two
years to get it right! And with all of these features, we absolutely
recommend that you take a few minutes to read through this
manual to familiarize yourself with all of the PZ-Pre functions
before you get started.
Like all Radial products, the PZ-Pre is built to the very highest
standards with the very best components and provides the type
of durability you would expect for concert stage use. If after read-
ing this manual you have a question, please visit the FAQ in the
PZ-Pre section of our web site. This is where we post the latest
notes. If you have a question that is not covered, please send
your email to [email protected] and we will do our very best
to get back to you promptly.
Now get ready to pluck, pick, bow, twang and strum till dawn!
Radial PZ-Pre™
Acoustic Instrument Preamp
User Guide
Table of Contents Page
Introduction...................................................................1
Feature Set...................................................................2
Input Section ................................................................4
Filter and EQ Section ...................................................6
Output Section..............................................................8
Instrument Connection .................................................9
Output Connection .......................................................11
Setting Up The PZ-Pre .................................................12
Controlling Feedback ...................................................14
Adding Effects To Your Sound ......................................16
Specications ...............................................................17
Warranty ................................................................Back Cover

True to the Music
Radial Engineering Ltd. PZ-Pre™User Guide
1
INTRODUCTION
The Radial PZ-Pre is a very unique pedal. Although the PZ-Pre
is likely to be the best sounding acoustic guitar preamp you have
ever experienced, it is not dedicated to just guitars. We designed
the PZ-Pre from the ground up to work with all types of instruments
including violin, cello, contrabass, mandolin, Dobro, bouzouki, harp,
sitar and banjo! This is because the two inputs have been designed
to accept all types of pickups and the on-board equalizer is both
very powerful and musical. You can even combine the two inputs
should you wish to use two pickups at the same time!
Our quest for exibility did not stop there; we also equipped the
PZ-Pre with four outputs so that it could drive four separate signal
paths at the same time! And each output is managed differently to
address different needs.
The instrument amplier output is designed for the on-stage musi-
cian. An electric ddle player may have numerous effects pedals
and an over-driven guitar amp on stage to create various sonic
textures while a bouzouki player may have his vintage Fender®
Twin™. Their is an output for your electronic tuner and the mute
footswitch lets you tune in silent or change instruments.
There are also two built-in Radial direct boxes with balanced XLR
outputs to connect you to the PA or recording system. Output-1 is
a pre-EQ, pre-effects output designed to send a clean signal to the
PA system while output-2 is post-EQ and post effects to feed stage
monitors and in-ear systems with a completely different mix. For
instance, when playing in a typical arena, there is so much echo
that the last thing you would want would be to send a ‘wet instru-
ment’ (sound with lots of echo and reverb) into the PA system. On
the other hand, adding reverb to your in-ear monitor system will
often give you a better sense of space and a more natural feel to
the performance.
The built-in exibility is further expanded with an effects loop,
power booster and probably the best sounding preamp you have
ever encountered for your instrument. Best of all, it is all housed
in a super compact pedal that can t in any gig bag and travel with
you wherever you go.

True to the Music
Radial Engineering Ltd. PZ-Pre™User Guide
2
1. INPUT-1: ¼" connection for rst instrument.
2. PZB-1: Recessed switch activates piezo buffer for input-1.
3. TOGGLE: Footswitch selects between input-1 and input-2.
4. BLEND-MIX: Recessed switch selects between toggle mode
and mix/blend mode.
5. INPUT-2: ¼" connection for second instrument.
6. LEVEL-1: Gain control for input-1.
7. LEVEL-2: Gain control for input 2.
8. NOTCH: Used to sweep the frequency of the notch lter.
9. HIGH: High frequency shelving EQ, boosts or cuts treble.
10. MID: Amplitude control for semi-parametric mid EQ.
11. FREQ: Frequency control for semi-parametric mid EQ.
12. LOW: Low frequency shelving EQ, boosts or cuts bass.
13. BOOST: Variable level control for the power booster.
14. MUTE: Footswitch mutes all outputs except tuner out.
15. LOOP ON: Forces the effects loop to remain on.
16. OUTPUT: ¼” out for instrument amplier.
17. PHASE: Inverts the signal polarity at the ¼" instrument output.
18. FOOTSWITCH ASSIGN: Sets function of boost footswitch
between power boost, effects loop or both.
19. BOOST: Footswitch activates power booster and/or effects
loop depending on setting of footswitch assign switch.
20. NOTCH Q: Sets the depth of the notch lter. Select between
normal, deep and bypass.
21. LO-CUT: High-pass lter removes low frequencies to eliminate
resonant feedback. Select between bypass and two low-cut settings.
FEATURES AND FUNCTIONS - TOP PANEL
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True to the Music
Radial Engineering Ltd. PZ-Pre™User Guide
3
22. PZB-2: Recessed switch activates piezo buffer for input-2.
23. LOOP SEND & RETURN: The built-in effects loop uses ¼”
jacks to connect effect pedals.
24. PRE-EQ: balanced XLR direct box out captures the dry signal
before the  lter, EQ, effects loop and boost sections. Outputs
an un-processed signal for the house PA or recording console.
25. LIFT: recessed ground lift switch disconnects pin-1 on both
XLR outputs to reduce hum and buzz caused by ground loops.
26. 180°: recessed switch reverses the polarity at the post-EQ
XLR output.
27. POST-EQ: balanced XLR direct box output sends a wet signal
for the monitor system so the player can control their on-stage
tone with the PZ-Pre.
28. TUNER: buffered ¼” output to feed an electronic tuner.
29. 15VDC-400mA: power supply connection 15 volts DC, center
pin positive.
25 26 27 28 29
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FEATURES AND FUNCTIONS - REAR PANEL

True to the Music
Radial Engineering Ltd. PZ-Pre™User Guide
Input-1 PZB 1 Blend-
Mix
Input-2 PZB 2
4
Input-1 and 2
The PZ-Pre features two ¼” inputs located on the right side panel.
The  exible dual input design lets a player connect and switch
between instruments simply by stomping on the TOGGLE footswitch.
Most performers, whether they play acoustic guitar or mandolin, tend
to have two instruments on stage. The second instrument is often
for backup should a string break; in some cases, it may be tuned
differently, or it may even be a completely different instrument! The
PZ-Pre is equipped to be a control center for two instruments.
Input-1
Input-2
Level-1
Level-2
Mute
Toggle
Footswitch
Tuner
Out
LEVEL-1 and 2
Both inputs are equipped with LEVEL
controls that let you adjust the volume
of each instrument. These controls
are used to compensate for the
differences in output level some
pickups produce. Once adjusted,
you can seamlessly switch between
instruments.
PZB-1 and 2 Piezo Pickup Buffers
Each PZ-Pre input features a special piezoelectric pickup (piezo)
buffer called the PZB that can be switched into the signal path
when needed. The PZB allows a passive piezo pickup to be
connected directly to the PZ-Pre without the use of a separate
preamp. The PZB increases the gain while elevating the input
impedance to 10meg Ohms. This ensures that the piezo pickup
'sees' the optimum input impedance for signal transfer which will
result in better tone. To
activate the PZB, use
a small screwdriver to
push in the recessed
switch. There is a
separate PZB switch
for each input channel.
INPUT SECTION

True to the Music
Radial Engineering Ltd. PZ-Pre™User Guide
Saddle
Pickup
Piezo
Pickup
TRS Jack &
Plug
Tip
Saddle Pickup
To CH-1
Ring
Piezo Pickup
To CH-2
5
Tuner Output
This buffered ¼” output is dedicated
for an electronic tuner. Since it is
buffered, connecting a tuner won’t load
down your pickup's tone. The TUNER
output is always on and can be used in
conjunction with the MUTE footswitch
to allow silent tuning.
Mute Footswitch with LED
Depressing this footswitch will mute all
outputs except the TUNER out. The
LED illuminates to indicate the PZ-Pre
is in mute mode. The MUTE footswitch
allows silent tuning on stage through the
TUNER output. The function may also
be used to mute your rig for instrument
change-over.
Blend-Mix
The BLEND-MIX function is typically used with instruments that
have two pickup elements or two different pickup systems. It
allows you to blend the two input channels using the LEVEL
controls to set up a mix. For instance, you can use the MIX mode
to blend an active on-board pickup with a passive piezo to create
a more natural acoustic sound. Alternatively, you can use the MIX
mode to connect two guitars to one amp for jamming with another
player. The MIX mode is activated by depressing the recessed
BLEND-MIX switch using a small screwdriver. The TOGGLE
footswitch will not work when the MIX mode is active.
Input-1 is specially equipped to allow a ¼” stereo TRS cable (Tip,
Ring, and Sleeve) to access both PZ-Pre channels. This feature
is designed for instruments that combine two pickup systems
through a stereo TRS jack. A stereo TRS cable will allow you
to connect both pickups to separate PZ-Pre inputs with a single
cable. From there you can toggle between the two pickup systems
or blend them together.

True to the Music
Radial Engineering Ltd. PZ-Pre™User Guide
Pre-EQ DI Output
This balanced XLR output is essentially
an active direct box. It produces a
600 Ohm, mic-level signal suitable
for multi-channel concert snake and
mixing console. It captures the dry
signal before the  lters and equalizer
section and is not affected by the
PHASE, BOOST and LOOP functions.
It is intended to feed a PA or recording
system with a clean, unprocessed
signal.
Ground Lift for Balanced XLR Outputs
The balanced XLR outputs are equipped with a recessed set-
and-forget ground LIFT switch on the rear panel to reduce hum
and buzz caused by ground loops. If you hear any noise, push in
the switch to help eliminate the problem.
Low-Cut Filter
The three position low-cut filter (also
known as a hi-pass filter) is designed
to eliminate low frequency resonant
feedback. Selecting either the 80Hz or
200Hz positions will roll-off low frequencies
preventing uncontrolled, run-away
resonant feedback. The LO-CUT filter
can be removed from the signal path by
setting it to BYPASS.
Notch Filter
To help control feedback, a sweepable notch
 lter allows you to focus on a very narrow
frequency and surgically remove it without
affecting the over-all tone of the instrument.
The notch filter on the PZ-Pre has two
controls: NOTCH sweeps the frequency
spectrum of the  lter from 56Hz to 220Hz
while the NOTCH Q switch controls the width
and attenuation of the  lter. The NORMAL
setting introduces a -8dB notch and the
DEEP setting introduces a -15dB notch. The
notch  lter can be removed from the signal
path by setting it to BYPASS.
PRE-EQ OUT, FILTER and EQ SECTIONS
Mixing Console
6
Low-Cut
Filter
Notch
Filter
3-Band
EQ
Power
Boost
Effect
Loop
Dry
Pre-EQ
Out
Input
Wet
Post-EQ
Out
Send Recv

True to the Music
Radial Engineering Ltd. PZ-Pre™User Guide
3-Band Semi-Parametric EQ
This three-band semi-parametric EQ is shared between the two
inputs. HIGH and LOW are shelving type EQ and adjust the
treble and bass response. The sweepable midrange EQ uses two
controls: MID controls the amount of boost or cut, while FREQ
sweeps the frequency spectrum.
7
Phase Reverse (¼” Stage Amp Output)
Technically speaking, this is actually
a polarity reverse switch that lets you
toggle the polarity of the signal at the
¼” instrument OUTPUT. This switch is
used to help reduce feedback when the
monitors or PA system coincide with the
instrument amp to cause a feedback
hot-spot where the performer is situated
on stage.
Boost and Effects Loop
The PZ-Pre is equipped with a power
booster and effects loop that can be
kicked in to create dynamic solos or
avant-garde textures. The power boost
and effects loop may be activated together
or separately, depending on the position
of the FOOTSWITCH ASSIGN switch.
Boost
When the FOOTSWITCH ASSIGN is
set to BOOST, depressing the BOOST
footswitch will only turn on and off the
variable power booster (effects loop is
bypassed). The BOOST knob sets the
level of the power booster with a maximum
of +12dB of clean boost. When set to
BOTH, depressing the footswitch will turn
both the effects loop and power booster on
or off. An LED illuminates when the loop,
booster, or both, are active.
Effects Loop
The ¼” effects loop SEND and RETURN
jacks are used to interface with standard
guitar effects pedals such as reverb, chorus
and delay. When the FOOTSWITCH
ASSIGN is set to LOOP, depressing the
BOOST footswitch will only turn on and
off the effects loop (power booster is
bypassed). The effect loop can be set to
stay on all the time by using the LOOP
ON switch next to the stage amp output.
Effects Loop

True to the Music
Radial Engineering Ltd. PZ-Pre™User Guide
180° Polarity Reverse
The POST-EQ XLR balanced output features a polarity reverse
for absolute phase alignment. This recessed switch will invert the
signal polarity of the POST-EQ XLR output by reversing pins-2
and 3 at the XLR connector. The default position for the switch is
pushed out where pin-2 is positive. This is the AES standard for
XLR connectors and is sometimes called 'pin-2 hot'.
8
OUTPUT SECTION
Post-EQ DI Output
This balanced XLR output is another active direct box. It produces
a 600 Ohm, mic-level signal suitable for connecting to mixing
consoles. The POST-EQ XLR OUT comes at the end of the PZ-
Pre signal path after the  lters, equalizer, PHASE, BOOST and
LOOP functions. It is intended to feed a stage monitoring system
or in-ear monitors allowing the player to control their on-stage
tone through the PZ-Pre controls.
XLR OUTS
Polarity Reverse
XLR OUTS
Ground Lift
Dry
Pre-EQ
Wet
Post-EQ
Low-Cut
Filter
Notch
Filter
3-Band
EQ
Power
Boost
Effect
Loop
Dry
Pre-EQ
Out
Input
Wet
Post-EQ
Out
Send Recv
¼" Instrument Amp Output
The ¼” OUTPUT jack connects to the musician’s on-stage
ampli er. This output is at the end of the PZ-Pre signal path and
is affected by all the controls.

True to the Music
Radial Engineering Ltd. PZ-Pre™User Guide
INSTRUMENT CONNECTIONS
Because the PZ-Pre can accept different kinds of pickups it’s
important to identify which type of pickup your instrument is
equipped with. Typical pickup systems include:
1. Magnetic (passive)
2. Piezo transducers (passive)
3. Magnetic or piezo with on-board preamp (active)
4. Combination magnetic and/or piezo with split output
Magnetic Pickups (Passive)
These types of pickups are sometimes mounted in the sound
hole of an acoustic guitar. They are referred to as passive
pickups because there are no electronics between the pickup and
instrument output jack. Magnetic pickups connect directly to the
PZ-Pre with an instrument cable. (PZB not required)
Piezo Transducers (Passive)
Piezo transducer pickups can be permanently mounted inside
an instrument, embedded in the bridge or attached to the sound
board with double sided tape. A piezo is considered passive when
there are no active electronics between the transducer and the
instrument output jack. The piezo transducer pickup converts
vibration into a very small electrical current. The current a piezo
produces is so small that it needs a specially designed amplier
or buffer to increase the signal to a workable level.
The PZ-Pre is equipped with a piezo buffer (PZB) on each input to
ensure the best possible tone from passive piezo pickups. When
connecting a piezo pickup to the PZ-Pre you should engage the
PZB for the input you’re connecting to. Set the switch to its 'inward'
position to engage the PZB.
9

True to the Music
Radial Engineering Ltd. PZ-Pre™User Guide
Magnetic or Piezo Pickups with On-board Preamp
Many electried acoustic instruments feature an on-board preamp
that works with internal pickup systems. The pickups may be
magnetic, piezo or a combination of both types. These instruments
are referred to as 'active' because there is a preamp between the
pickups and the instrument output that requires a power source
such as a battery. The preamp controls are usually mounted on
the side of the instrument.
Active instruments produce a signal that can connect to the PZ-Pre
without the need to engage the PZB. The instrument's on-board
preamp will buffer the signal and the output can connect directly
to the PZ-Pre with an instrument cable.
10
On-board Preamp
Controls
Combination Pickup Systems
Each type of pickup system has strengths and weaknesses. Some
players may use a combination of pickups to create a more natural
tone than either pickup system can produce alone.
You can connect both a magnetic and piezo pickup and use
the PZ-Pre's unique BLEND-MIX function to blend the outputs
together. Alternatively, the PZ-Pre can toggle between the pickups
to use the one that best suits the song being played.
Bridge Saddle Piezo
Magnetic Pickup
Stereo TRS
Output Jack

True to the Music
Radial Engineering Ltd. PZ-Pre™User Guide
11
OUTPUT CONNECTIONS
The PZ-Pre is equipped with four outputs, each of which is
designed for specic tasks to address various needs on stage.
Instrument Amplier Output
This ¼” guitar level output is designed to feed an on-stage guitar
amplier. Think of this output as your own personal ‘world’ where
you create your sound and get inspired. You may even set up a
mic in front of your stage amp so the FOH engineer can mix in
your effects with his room mix.
Tuner Output
This ¼” output is separately buffered so that connecting an
electronic tuner will not have any effect on the instrument tone
because of impedance loading. When the MUTE footswitch is
depressed, all other outputs are turned off while the tuner output
remains active. This lets you quietly tune on stage or change
instruments without disrupting the audience.
Pre-EQ and Effects XLR (Dry Direct Box) Output
This balanced mic level XLR output is designed to go into the PA
system. It is ‘dry’ and unprocessed so that the FOH engineer can
treat this signal to optimize the sound in the PA. For instance,
you may want reverb on stage, but in an arena, this is likely the
last thing that is needed. This is also a great place to connect a
recorder if you plan to produce a CD afterwards. With a clean,
unprocessed track, you can add effects such as reverb or chorus
in post-production or even re-amplify the signal using the Radial
X-Amp. None of the effects, EQ or notch lter will affect this
output.
Post-EQ and Effects XLR (Wet Direct Box) Output
This is primarily designed to feed stage monitors, but is also where
you would connect your PZ-Pre to the PA if you do not have a
FOH engineer running the PA system. For monitoring, you can
have all of your effects on and create the stage mix that sounds
best to you without interfering with what the FOH engineer may
require. You can also send a wet mix to the house PA and the
FOH engineer can combine both feeds!

True to the Music
Radial Engineering Ltd. PZ-Pre™User Guide
SETTING UP THE PZ-PRE
Always make sure the equipment you are connecting to is either
turned off or the volumes are set to zero. This will eliminate any
power-up transient pops from harming the loudspeakers. To avoid
potential for electric shock, only connect the PZ-Pre to properly
grounded audio equipment. If your instrument uses an on-board
preamp, ensure the battery is fresh and fully charged.
To start, set the PZ-Pre to a neutral setting as shown below.
Connect the power supply and toggle the MUTE and BOOST
footswitches to their off positions.
Setting Instrument Levels
1. Start with your primary instrument connected to INPUT-1.
2. Determine the type of pickup you are connecting. If it is a passive
piezo pickup, activate the piezo buffer with the PZB-1 switch.
3. Stomp on the TOGGLE footswitch until LED-1 illuminates.
4. Turn on your instrument amplier or sound system.
5. Slowly turn LEVEL-1 clockwise and set a comfortable listening
level.
12
USING THE PZ-PRE EQ CONTROLS
Before you head off to your rst gig with the PZ-Pre, it is a good
idea to familiarize yourself with the controls in your practice room
and investigate the various functions. Do this at a low volume level
rst so that you do not cause feedback. Listen to the LO-CUT
(high-pass lter) and how it affects the tone of your instrument.
You will probably nd that using it will clean up the bottom end
of your sound without affecting the overall tone. In fact, if you
are playing with a drummer and bassist, you will likely nd that
ltering the lower registers of your instrument can really improve
the overall mix!
Now listen to the EQ. You will notice that the bass and treble
controls are quite powerful! So be careful! Less is always best
when it comes to equalization. Creating a big, fat sound with lots
of bottom end and a super crisp high end may sound good in
your basement, but live, these frequencies tend to muddy up the
bottom end and cause the high end to get very harsh, especially if
you have mid-range horns in your PA. Furthermore, feedback with
acoustic instruments occurs when the sound resonates from the
PA back into the instrument pickup system. Feedback increases
exponentially when you add lots of bass or treble!

True to the Music
Radial Engineering Ltd. PZ-Pre™User Guide
13
The MID control is very important to getting your sound right.
Each instrument tends to work within a given sonic range. For
instance, a violin’s range is much higher than that of a cello or
double bass. However, the character of the instrument is usually in
the mid range. This is also where human hearing is most ef cient.
The PZ-Pre has a semi-parametric mid-range EQ with one knob
that adjusts the center frequency (FREQ) and another that controls
the intensity (MID). You can cut or boost any frequency within
the controls' range of 82Hz to 5.6kHz. This is also where most
folks get into trouble. Because human ears are most sensitive to
mid-range, we tend to naturally cut it back. Now if you take out
the very essence of the instrument before it gets to the PA, what
do you expect the audience to hear? This is why we included a
separate Pre-EQ output for the front of house PA system. The
Pre-EQ output will give the house engineer a full-range signal to
mix with while the PZ-Pre EQ controls can be adjusted to suit you.
However, in any case be careful not to over-EQ your tone!
The sweep function of the FREQ control is designed to  nd the
range best suited to your instrument’s natural tone. Start by setting
the MID control at 2 o’clock and then sweep the FREQ control
until you  nd the spot where your instrument seems to resonate
at an unpleasant frequency. Then back-off the MID control to
approximately 10 o’clock and listen. Try playing at soft and then
louder volumes to see what happens. Then try  ne tuning the
FREQ control to see where it sounds best. Setting an EQ is more
of an art than a science but you can not go wrong if you follow
EQ rule number 1: Less is Best!
TIP: The twelve o'clock position is neutral, or zero
boost/cut, for the BASS, TREBLE, and MID controls.
Turning these controls clockwise will increase, or
boost the amplitude while turning counter-clockwise
will decrease, or cut.
Set the MID control to a boost or cut position in order
to hear the sweep of the FREQ control.
BoostCut
0 dB

True to the Music
Radial Engineering Ltd. PZ-Pre™User Guide
14
CONTROLLING FEEDBACK
The PZ-Pre gives you low-cut and notch lter tools to suppress
feedback and achieve the greatest amount of signal gain. This
concept is called gain before feedback. This section of the
manual will help you set up the PZ-Pre for maximum gain before
feedback.
To test for feedback you should be positioned in the area on stage
where you will be performing. Always test for feedback with your
amp, monitors and PA system turned on.
TIP: Feedback can be very unpleasant to listen to. The
MUTE footswitch can be used as a panic button in case of
uncontrolled run-away feedback. Dampening the strings with
one hand while you adjust the PZ-Pre controls is another
method to control feedback while testing.
Begin your feedback testing by increasing the LEVEL control to
the point where your instrument starts to feedback. Play your
instrument, move around on stage and experience the effect.
At this point, you will likely hear two types of feedback: feedback
when a specic note sounds and a low frequency run-away
resonance. The feedback from a specic note we will deal with
later, using the notch lter. For now, we will focus on removing
the runaway low resonance with the LO-CUT lter.
LO-CUT Filter
The goal for using the LO-CUT lter is to be able to strum the open
strings loud and clear without run-away low frequency resonance
feedback. This type of feedback can often be eliminated simply
by engaging the LO-CUT lter.
Try this by setting the LO-CUT control to the 80Hz position. In-
crease the volume and see what happens. If you get more of the
same resonance feedback, try the 200Hz position. In this position,
you can hear that more bass frequencies have been removed
from the signal but your instrument can have more gain before
the feeback starts.
Setting the LO-CUT Filter
1. Set the LO-CUT switch to bypass.
2. Perform this test by strumming open strings.
3. Slowly turn up the LEVEL control until low frequency feedback
starts to make the open strings resonate.
4. Set the LO-CUT switch to 80Hz.
5. Continue to slowly increase the LEVEL control to the point
where low frequency feedback re-occurs.
6. Turn the LEVEL control down a little from this point.
7. If more gain is needed, set the LO-CUT to 200Hz and increase
the LEVEL control.

True to the Music
Radial Engineering Ltd. PZ-Pre™User Guide
Notch Filter
The notch lter is designed to manage feedback by surgically re-
moving an offending frequency while leaving the rest of the sound
intact. To nd which note is going to feedback rst, play ascending
scales starting from your instrument's lowest note.
During your tests, if you hear that a particular note is more prone
to feedback than others, set the NOTCH Q to the NORMAL posi-
tion and slowly rotate the NOTCH control to see if you can dial
in the offending frequency. This process is sometimes referred
to as 'notching out'.
When you have found the position on the dial that corresponds
to the frequency that is feeding back, play and hold a chord or
simply let all of the strings resonate. Now, turn the LEVEL control
up some more and see what happens. If the same frequency is
still on the verge of feedback, try setting NOTCH Q to DEEP.
An important point when using the NOTCH lter is that the prob-
lem frequency will likely change each time you play in a different
venue or change instruments. So experiment and get familiar
with the NOTCH lter functions. This will make sound-check go
more quickly and will reduce the occurrence of feedback when
you are performing!
Setting the Notch Filter
1. Set the NOTCH Q switch to bypass.
2. Test by playing ascending notes on the lowest strings.
3. Focus in on the note that tends to feedback before the rest. If
necessary, increase the LEVEL control to produce a perpetual
feedback ring at this note's frequency.
4. Set the NOTCH Q switch to NORM.
5. While holding the note, turn the NOTCH control until you have
tuned the lter to the same frequency. The notch lter is tuned
when the note decays naturally without feeding back.
6. Increase the LEVEL control until the same note starts to
feedback and then back off the level a little.
7. If more gain is needed, you can switch the NOTCH Q to DEEP
and try increasing the LEVEL control some more.
TIP: At some point, turning up the instrument level will
cause uncontrollable feedback at many frequencies and is
an indication levels should be lowered.
15

True to the Music
Radial Engineering Ltd. PZ-Pre™User Guide
16
ADDING EFFECTS TO YOUR SOUND
For the most  exibility, the PZ-Pre is equipped with an effects loop
that can be linked to the power BOOST footswitch or set to remain
on. When linked to the BOOST footswitch, you can turn on and
off a string of effects with one footswitch. When the loop is set to
remain on you can control your pedals in a traditional way where
each pedal is activated or bypassed using its own footswitch.
The effects loop is heard at the ¼" amp output as well as the
Post-EQ direct out. However, the effects will not be heard at the
tuner out which can help improve tuner response and they will
not be heard at the Pre-EQ direct out giving you  exibility to send
clean or wet signals to the PA.
Effects
Loop
Input-1
Input-2
¼" Amp
Out
Pre-EQ
XLR Out
Post-EQ
XLR Out
Tuner
Out Send Recv
Toggle
Wet
Wet
Dry
Dry
EQ
The loop is equipped with ¼" send and receive jacks on the rear
panel that connect to the effect pedal using standard coaxial cables.
Using the Loop With The Boost Footswitch
The three position FOOTSWITCH ASSIGN switch links the ef-
fects loop to the BOOST footswitch. The  rst setting is BOTH
where stomping on the footswitch will turn on the booster and
the effects loop. You can use this setting to introduce an effect
such as  anging or echo along with a volume boost to enhance
a solo. The middle setting, BOOST, allows
the footswitch to only control the power
boost function while the loop remains off.
The last setting, LOOP, does the opposite
and allows the footswitch to control just the
loop. The power boost function remains off.
Using the Loop On Setting
The LOOP ON switch, located on the left
side next to the ¼" output, allows the effects
loop to remain on. Using the LOOP ON
setting will allow you to control your effects
individually using their own footswitches.
The switch is recessed so use a small
screwdriver to access it. When pushed
in, the FOOTSWITCH ASSIGN switch is
deactivated and the effects loop remains
on all the time. The BOOST footswitch is
then dedicated to the power boost function.
Loop on
switch

True to the Music
Radial Engineering Ltd. PZ-Pre™User Guide
Radial PZ-Pre Speci cations
Inputs 1 & 2: ¼" Phone unbalanced
Input impedance: Normal 6.8k Ohm
Piezo 10Meg Ohm
PZB buffers: +10dB boost
Low-cut  lter: 75Hz / 220Hz
Notch  lter range: 56Hz - 330Hz
Notch Q: -8dB / -15dB
Low EQ: Shelving type +/-12dB (75Hz)
High EQ: Shelving type +/-12dB (7.5kHz)
Mid EQ: Semi-parametric
+/-12dB (82Hz - 5.6kHz)
Power Boost: Unity gain to +12dB max.
Effects Loop: ¼" Phone unbalanced
Send 1k Ohm / Return 15k Ohm
Switching: FET Switching
Output (instrument): ¼" Phone unbalanced,
1k Ohm output impedance
Tuner output: ¼" Phone unbalanced,
6.8k Ohm output impedance
Pre-EQ output: XLR, balanced,
600 Ohm, mic-level
Post EQ output: XLR, balanced,
600 Ohm, mic-level
XLR pin-out:
(AES standard)
pin 1 ground
pin 2 hot (+)
pin 3 cold (-)
Power supply: 15VDC, 400mA (included),
center pin positive
Size (W x D x H): 8”x 4.25”x1.37” (203x108x35mm)
Weight: 2.65 lbs. (1.2 kg)
Warranty: 3 Years, transferable
17

Tonebone PZ-Pre Users Guide - Part #: R870 1205 10
Appearance and speci cations subject to change without notice.
Copyright © 2015 Radial Engineering Ltd. all rights reserved.
®
www.radialeng.com
THREE YEAR TRANSFERABLE LIMITED WARRANTY
RADIAL ENGINEERING LTD. (“Radial”) warrants this product to be free from defects in mate-
rial and workmanship and will remedy any such defects free of charge according to the terms
of this warranty. Radial will repair or replace (at its option) any defective component(s) of this
product (excluding  nish and wear and tear on components under normal use) for a period of
three (3) years from the original date of purchase. In the event that a particular product is no
longer available, Radial reserves the right to replace the product with a similar product of equal
or greater value. In the unlikely event that a defect is uncovered, please call 604-942-1001 or
email [email protected] to obtain a RA number (Return Authorization number) before the
3 year warranty period expires. The product must be returned prepaid in the original shipping
container (or equivalent) to Radial or to an authorized Radial repair center and you must as-
sume the risk of loss or damage. A copy of the original invoice showing date of purchase and
the dealer name must accompany any request for work to be performed under this limited and
transferable warranty. This warranty shall not apply if the product has been damaged due to
abuse, misuse, misapplication, accident or as a result of service or modi cation by any other
than an authorized Radial repair center.
THERE ARE NO EXPRESSED WARRANTIES OTHER THAN THOSE ON THE FACE HERE-
OF AND DESCRIBED ABOVE. NO WARRANTIES WHETHER EXPRESSED OR IMPLIED,
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GIVES YOU SPECIFIC LEGAL RIGHTS, AND YOU MAY ALSO HAVE OTHER RIGHTS,
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1588 Kebet Way, Port Coquitlam BC V3C 5M5
tel: [phone] • fax: [phone]
[email protected] • www.radialeng.com
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