SZiKLA PRODIGAL Assembly instructions

1
PRODIGAL DUAL
CHANNEL STRIP
& MONITOR STATION
User Reference Manual
V5.1

2
PRODIGAL SAFETY SPECIFICATIONS
===========================================
Review the following safety precautions to avoid injury and prevent damage to this
product or any products connected to it. To avoid potential hazards use this product only
as specified.
Only qualified personnel should perform service procedures. There are no user-adjust-
able components inside the unit. Unqualified persons should not remove the protective
cover.
To Avoid Fire or Personal Injury:
Use proper power cord. Use only the power cord specified for this device and certified for
the country of use.
Ground the product. To avoid electric shock this product is grounded through the ground-
ing conductor of the power cord. Only use a power cord with a ground pin. Check power
cord regularly to ensure that the continuity of the ground pin is maintained and conforms
to the safety requirements in your region.
Use the correct voltage setting. Before turning on device, ensure that the Voltage Selec-
tor Switch is set to the correct voltage range for region of use. Attempting to operate the
device using the incorrect voltage setting may cause damage to the device and/or failure of
the device and/or destruction of the protective fuse.
Use the correct fuse. Use only the fuse type and rating specified for the device. Differ-
ent fuses are required if the Voltage Selector Switch is changed to the opposite position.
Please refer to the instructions on the rear panel of the device to determine the correct fuse
required. When replacing blown fuses, only replace with a fuse of the same size, type and
voltage rating.
Do not obstruct air vents. Vent slots and holes are important for cooling the unit. Do not
cover or obstruct any of the vents or overheating and equipment failure may occur.
Do not operate with suspected failures. If you suspect that there is damage to this equip-
ment, have it inspected by qualified service personnel.
Do not expose unit to rain or moisture.
For safety and reliable operation, keep product surfaces clean and dry.
Do not rest drinks on lid of unit.
You will tip one over, it will go in through the vent, smoke will come out, you will cry.
Safety Compliance:
This device is designed to meet or exceed Australian and International Safety Standards:
AS/NZS3820, Essential safety requirements for low voltage electrical equipment.
AS/NZS/IEC60065, Audio video and similar electronic apparatus safety requirements.
Safety Class: Class 1 - Grounded Product.

3
PRODIGAL CARE OF UNIT
===========================================
Keep the Carton and Styrene Packaging in
case of the need to re-ship or service the
unit.
Rubber Feet are provided for when the
Prodigal is used on a Table-Top.
To protect and preserve the unit’s met-
alwork and finish, always use washers
when screwing unit into a rack.
To avoid audible thumps, always turn off
monitors before turning off Prodigal.

4
CONTENTS
–PRELIMINARY –
Safety Precautions 2
Care of Unit 3
–DIAGRAMS –
Front Panel Features 5
Rear Panel Features 6
Connection Diagram 7
Channel Strip Block Diagram 8
Monitor Section Block Diagram 9
–INPUTS & OUTPUTS –
Main In 10
Main Out 10
Playback In 11
Studio Monitors Out 11
–CHANNEL STRIP OPERATION –
Main Input Selectors 12
Phantom Power 12
Preamplifier 13
EQ 14
De-Mud 14
Air 14
De-Esser 15
Compressor/Limiter 16
Output Fader 18
–METERING –
Input Meter 19
Out/Comp/De-Ess Meter 19
Peak LED Indicators 20
–MONITOR STATION OPERATION –
Introduction 21
Prodigal Monitor Input 22
Playback Monitor Input 23
Studio Monitor Outputs 24
Headphones Output 25
–SYSTEM ALIGNMENT –
Full Procedure 26
–AUDIO CABLE GUIDE –
Introduction 28
Misc Inputs 29
Connecting to Balanced Devices 30
Connecting to Unbalanced Devices 31
–TECHNICAL SPECIFICATIONS –
Prodigal Channel Strip 33
Monitor Section 35

5
PRODIGAL Dual Analog Channel Strip & Monitor Station
www.szikla.com
Input Preamp
Processes all signals from selected inputs.
Silky smooth, mirror balanced,
low current discrete transistor design.
Includes P48 for Mic XLR, 20dB Pad,
Phase Reverse, 30dB Gain Control Pot,
Upper and Lower +0/-3dB (12dB/octave)
Bandwidth adjust.
Input Meter
Shows post-gain/pre-EQ input level.
Displays solid VU bar with
Peak Level dot above it. Peak
hold is 3 sec with 18dB/sec decay.
Units expressed as -dB Full Scale.
Switchable
Output/Compressor/De-Esser Meter
Output Meter
Shows post-fader output level in -dB Full Scale.
Displays solid VU bar with
Peak Level dot above it. Peak
hold is 3 sec with 18dB/sec decay.
-18dBFS corresponds to +4dBu at XLR output.
Compressor Meter/De-Esser Meter
Direct display of gain reduction in dB.
Displays solid bar with zero LED permanently lit.
Output Fader
Adjusts output level
of Channel Strip.
Input Selector
Rear panel XLR Mic or Line,
Balanced/Unbalanced.
Front Panel TRS Line or Instrument D.I.
Balanced/Unbalanced.
Front Jacks are also useful when you are
using the Channel Strip as an insert,
or printing tracks.
Monitor Station
Central listening control section.
Mix local audio at zero latency
with DAW playback or other source
and send all via separate master faders to
Phones and/or Studio Monitor outputs 1 & 2.
Playback input 3 is configured to receive TRS
headphone output from your smart-phone, which
may also be confugured to serve as a talk-back mic.
Headphone amp is designed to drive your phones
LOUD.
EQ
Single band, tight, responsive, and sweepable over 6.5 octaves.
+/-10dB Cut/Boost, 1 octave, Constant Q.
De-Mud
Simple and handy fixed band that targets the un-musical LF in a vocal,
instrument or live room. Low Cut -3dB at 300Hz, 1 octave wide.
Air
Enhances the edges and air around vocals, strings, etc.
Helps bring vocals forward. Fixed Band of High Boost
Flat to 9KHz, +1dB/10KHz,+10dB/20KHz.
Accurate phase up to 20KHz and no dip below the boost band.
De-Ess
Reduces sibilance in Vocals, etc.
Applies natural sounding active FET limiting to
the high frequency band. Hz control sets
the crossover point. Ess control sets the operating
threshold which is tied to and varies with a
fast-averaged sample of the full-bandwidth signal.
This helps keep the amount of De-Essing consistent
regardless of program volume and dynamics.
Attack=0.5mS Release=40mS.
Limit LED glows dynamically as limiting occurs.
Left and Right channel FETs are hand-matched.
Compress/Limit
Transparently reduces dynamic peaks in program material.
Applies ultra fast FET soft-knee limiting with faithful
harmonics and sparkling linear phase. Compress control
varies compression ratio and threshold together so
that more input signal results in more compression with
peaks maintained at around -12dBFS. Great for airy vocals, or
producing tight, level bass tracks. Loves being driven super hard.
Attack=5uS~2.5mS Release=50mS~1.3 Sec.
Limit LED glows dynamically as limiting occurs, and reaches
full illumination at the maximum gain reduction of -22dB.
Left and Right channel FETs are hand-matched
for seemless alignment of stereo image. FRONT PANEL

6
PRODIGAL Dual Analog Channel Strip & Monitor Station
www.szikla.com
Multi-Region,Three Transformer Power Supply
AC inlet voltage range may be switched
after removal of transparent anti-tamper cover.
Users should determine the appropriate
voltage setting for their country.
Three separate power transformers internally
supply different parts of the circuitry, helping
to reduce magnetic fields and increase isolation.
Main XLR Inputs
Accepts balanced or unbalanced
Microphone or Line level inputs.
Pin 2 is Hot.
300mm Deep, 3 Rack Unit Metal Enclosure
Users may choose to bolt the Prodigal into a rack,
or by incorporating the optional jumbo rubber feet,
use it as a table-top unit with room on top for a
notebook computer or monitor.
With the further addition of powered speakers,
ADC and a good microphone the Prodigal has all
it needs to function as the hub of a compact, or even
portable, high quality professional recording setup.
Dimensions HxWxD:
Overall: 132mm x 482mm x 339mm
Brushed Aluminium Front Panel: 132mm x 482mm x 3mm
Brass Plated Rack Ears: 132mm x 47mm x 3mm
Powdercoated Zinc Enclosure: 126mm x 430mm x 300mm
AC Power:
Power consumption: 40W max
AC Voltage Required: 110-120VAC or 220-240VAC
Designed to meet or exceed necessary Australian and International
Safety Standards: AS/NZS3820,AS/NZS60065, IEC60065
Main XLR Outputs
Connects to your DAW
or other balanced or unbalanced
Line or Auxiliary level equipment.
Output Meter level of -18dBFS
corresponds with +4dBu at XLR
between pins 2 and 3.
Output pad switch reduces
that level to -10dBV.
Pin 2 is Hot.
Playback Inputs 1 & 2
Accepts balanced or unbalanced
signals from your DAW, CD player,
tape player or other device. Input
gain switch allows easy alignment
of input to professional +4dBu or
domestic -10dBV equipment levels.
Tip is Hot, Ring is Cold, Sleeve is Shield.
Stuio Monitor Outputs 1 & 2
Connects to balanced or unbalanced
inputs of powered Studio Monitors and
sub-woofers, loudspeaker amplifiers,
headphone amplifiers, and other devices.
Can also be used as a sub-mix output.
Level trim pot allows easy micro-alignment
of output between professional +4dBu
or domestic -10dBV equipment levels,
or for instance to align main speakers on
output 1 with sub-woofers on output 2.
Tip is Hot, Ring is Cold, Sleeve is Shield.
REAR PANEL

7
PRODIGAL Dual Analog Channel Strip & Monitor Station
www.szikla.com
BLOCK DIAGRAM
PRODIGAL CHANNEL STRIP
P48
DE-
MUD EQ AIR
MTR
SEL.
MASTER
FADER
OUT
BW
Hz
MIC/
LINE
20dB
PAD
Ø
REV
LINE/
INST
XLR/
JACK
INPUT SEL.
INPUT METER OUTPUT/DE-ESSER/COMPRESSOR METER
LR LINK
PRODIGAL
MIX BUS
LR
MAIN IN LEFT
MAIN OUT LEFT
+4/-10
GAIN BUFF
AMP
PRE
LINE BAL/
UNBAL
PKPK LIMIT LIMIT
DE-
ESS
DUAL MONO
LINK
COMPRESS/
LIMIT
12345625 21 15 12 1030 818 040
L
R
12345625 21 15 12 1030 818 040
L
R
P48
DE-
MUD EQ AIR
MASTER
FADER
OUT
BW
Hz
MIC/
LINE
20dB
PAD
Ø
REV
LINE/
INST
XLR/
JACK
INPUT SEL.
MAIN IN RIGHT
MAIN OUT RIGHT
+4/-10
GAIN BUFF
AMP
PRE
LINE
BAL/
UNBAL
PKPK LIMIT LIMIT
DE-
ESS
COMPRESS/
LIMIT
audio
gnd
case
direct
gnd
case
r.f.
gnd

8
PRODIGAL Dual Analog Channel Strip & Monitor Station
www.szikla.com
PRODIGAL
MIX BUS
LR
BLOCK DIAGRAM
PRODIGAL MONITOR STATION
MONO
MONO MUTE/
IN
PLAYBACK IN 1
LEFT
BUFF
AMP
PRE
PK
INPUT SEL.
RIGHT
+4/-10
BUFF
AMP
PRE
SUM
PLAYBACK IN 2
LEFT
BUFF
AMP
PRE
AMP
PWR
RIGHT
+4/-10
BUFF
AMP
PRE
PLAYBACK IN 3
PRODIGAL
OFF
LEFT BUFF
RIGHT
LEFT
RIGHT
BUFF
BUFF
BUFF
STUDIO MONITOR OUT 1
HEADPHONES OUT
LINE BAL/
UNBAL
LEFT
RIGHT
LEFT
RIGHT
LINE
BUFF
BUFF
BUFF
BUFF
BAL/
UNBAL
PLAYBACK
FADER
PRODIGAL
FADER
STUDIO
FADER
PHONES
FADER
MONITOR
MIX BUS
LR
SUM MUTE/
IN
TRIM
+4/−10
LEFT
RIGHT
STUDIO MONITOR OUT 2
LINE BAL/
UNBAL
LINE
BUFF
BUFF BAL/
UNBAL
MUTE/
IN
TRIM
+4/−10
audio
gnd
case
direct
gnd
case
r.f.
gnd

9
OUT
Line
Bal/Unbal
IN
Mic/Line
Bal/Unbal
R
L
STUDIO MONITORS
OUT
Bal/Unbal
PLAYBACK
IN
Bal/Unbal
R
L
R
L
+4dB
-10dB
+4dB
-10dB
+4dB
-10dB
FUSE
220 - 240V: 0.5A SLOW 250V
110 - 120V: 1A SLOW 250V
AC INPUT: 50-60 Hz 40W
220 - 240V
110 - 120V
+4dB-10dB +4dB-10dB
PRODIGAL
DUAL CHANNEL STRIP
SZIKLA TECHNICAL
MADE IN AUSTRALIA
szikla.com
P2
WARNING
DO NOTREMOVE COVER
RISK OF ELECTRIC SHOCK
NO USER SERVICEABLE PARTS INSIDE
FOR SERVICING - REFER TO QUALIFIED SERVICE PERSONNEL
WARNING: TO REDUCE THE RISK OF ELECTRIC SHOCK
DO NOT EXPOSE THIS EQUIPMENT TORAIN OR MOISTURE
CONNECT ONLYTO A MAINS OUTLET WITH SAFETY EARTH
WARNING: INCORRECT ACVOLTAGE SETTING MAY DAMAGE THIS EQUIPMENT
MONITOR MONITOR
MAIN
PRODIGAL
DUAL CHANNEL STRIP
COMPRESS ATTACK RELEASE
23
1
PRODIGAL
IN
HzHz
IN
INPAD IN INØ REV DE-MUD
Hz ESS
20020
75
20K2K
7.5
10K100
750
-dB+
LR LINK
L
R
L
R
10K1K
4
SF SF20:11:1
4
8
16
2
3
IN
INPUT
COMPRESS ATTACK RELEASE
HzHz
LIMIT
IN
P
48
P 48
PAD INØ REV DE-MUD
AIR
AIR
Hz ESS
- dB +
1
STUDIO MONITORS
PHONES
2
IN
12345625 21 15 12 1030 818 040
12345625 21 15 12 1030 818 040
12345625 21 15 12 1030 818 040
12345625 21 15 12 1030 818 040
MONITOR
LIMIT
LIMIT
LIMIT
INPUT
1010
0
MAXMIN
OUT
PLAYBACK
POWER
IN
+0
5
10
15
20
25
30
OUT
20020
75
10K1K
4
SF SF20:11:1
4
8
16
2
3
1010
0
MAXMIN
STUDIO
MONO MONO
DUAL MONO
OUT
20K2K
7.5
10K100
750
STATE
SOLID
∞MAX
1
2
3
456
7
8
9
INST
LINE
OFF
PK
∞+6
0
10
20
+0
10
25
+0
5
10
15
20
25
30
+0
10
25
∞+6
0
10
20
Ø REV
IN
P
48
10
IN
LIMIT
DE MUD
AIR
1
S
2
IN
PAD
0
LIMIT
D
O
PRODIGAL Dual Analog Channel Strip & Monitor Station
www.szikla.com
PRODIGAL
CONNECTION DIAGRAM
HIGH IMPEDANCE INSTRUMENT
LINE LEVEL AUDIO SOURCE
MIX MONITOR OR HEADPHONE AMP
MAIN POWERED SPEAKERS CD, TAPE OR OTHER AUDIO REFERENCE DIGITAL/ANALOG WORK STATION
INSERT/PRINT
PLAYBACK
RECORD
LINE LEVEL
AUDIO SOURCE
MICROPHONE
HEADPHONES
PHONE. (CAN ALSO BE
CONFIGURED AS A
TALK-BACK MIC)

10
QUICK START:
Main Inputs for the Prodigal:
• Rear XLR at Microphone or Line level
• Front TRS Jack for Line device or Instrument.
- A Front TRS Jack is also a useful place to
run a channel of playback from your work-
station for processing and printing back into
your mix.
All inputs accept balanced or unbalanced connec-
tions, according to the following standard
XLR pin 2 Hot, 3 Cold, 1 Shield
TRS JACK Tip Hot, Ring Cold, Shield
Inputs are selected via front panel Left and Right
Rotary Input Selector Switches.
MORE DETAIL:
See MAIN INPUT SELECTORS section.
QUICK START:
The Main XLR Output connects to your DAW or
other Line or Auxiliary level equipment.
This output can operate balanced or unbalanced:
pin 2 Hot, 3 Cold, 1 Shield.
+4dB/–10dB button sets the nominal output level
which should be selected to match the input sen-
sitivity of the downstream device. Output Meter
level of –18dBFS corresponds to a level between
XLR pins 2 and 3 of +4dBu, or –10dBV when but-
ton is depressed.
These XLRs are always connected downstream of
the main Output Faders, and can be muted by
rotating the respective Left or Right OUT knob
fully anticlockwise. It is usually more convenient
to mute Prodigal audio at the channel input of
the downstream device.
PRODIGAL MAIN INPUTS PRODIGAL MAIN OUTPUT

11
QUICK START:
The Playback Monitor Inputs allow you to moni-
tor playback from your DAW and other devices.
PLAYBACK IN 1 and 2 TRS Jack inputs accept
Line or Auxiliary level balanced or unbalanced
connections: Tip Hot, Ring Cold, Shield. Plug
your DAW into one of these.
+4dB/–10dB button sets the nominal input level
which should be selected to match the output
level of the DAW or other input device.
PLAYBACK IN 3 Mini-Jack input is configured to
receive the stereo headphone signal from a mo-
bile phone or personal music player, Tip Left,
Ring Right, Shield Common.
Inputs are selected via front panel PLAYBACK Ro-
tary Input Selector Switch.
MORE DETAIL:
See PLAYBACK MONITOR INPUT in MONITOR sec-
tion.
QUICK START:
The Studio Monitor Outputs allow your Monitor
Mix to be sent to external speakers, subwoofers,
headphone amplifiers, submix recorders and any
other Line or Aux level device.
STUDIO MONITORS OUT 1 and 2 TRS Jack out-
puts can operate balanced or unbalanced: Tip
Hot, Ring Cold, Shield.
+4dB/–10dB knob sets the nominal output level
and should be trimmed to match the input sensi-
tivity of the downstream device, normally +4dBu
or –10dBV. Variable potentiometers are provided
rather than switches to make it easier to match
levels between two different downstream devic-
es, such as say a pair of powered speakers on
Output 1 and a subwoofer on Output 2.
Outputs are selected via front panel STUDIO
MONITORS 1 & 2 buttons.
MORE DETAIL:
See STUDIO MONITOR OUTPUTS in MONITOR sec-
tion.
PLAYBACK MONITOR INPUTS STUDIO MONITOR OUTPUTS

12
QUICK START:
The Main Input Selectors are rotary switches that
select:
• Rear XLR at Microphone or Line level
• Front TRS Jack for Line device or Instrument
All inputs can accept balanced or unbalanced
connections.
MIC position selects Rear XLR at high gain for
microphones.
LINE position selects Rear XLR at low gain for line
level devices.
LINE position 2 selects Front TRS Jack at low gain
for line level devices.
INST position selects Front TRS Jack at low gain
for direct inject of high impedance instruments.
MORE DETAIL:
The Main Input Selectors are rotary switches that
select:
• Rear XLR at Microphone or Line level
• Front TRS Jack for Line device or Instrument
All inputs can accept balanced or unbalanced
connections.
Input switching is done via relays to reduce the
signal path and maintain high quality. No audio
passes through the Input Selector Switch.
MIC position selects Rear XLR at high gain for
microphones.Inputimpedanceissetfor1.3kΩ,
and Pin 2 is Hot.
LINE position selects Rear XLR at low gain for line
level devices. Input impedance is set for 11kΩ,
and Pin 2 is Hot.
LINE position 2 selects Front TRS Jack at low
gain for line level devices. Input impedance is set
for10kΩ.TipisHot,RingisCold.TheRearXLR
is the preferred input for line level devices, as
it can cope with input signals of up to +42dBu,
compared with a maximum of +22dBu here due
to differences in input buffering. But the acces-
sibility of the Front TRS Jack makes it somewhat
more convenient and useful for plugging in a line
level instrument such as a keyboard. It is also a
handy place to run a channel of playback from
your workstation for processing and printing
back into your mix.
INST position selects Front TRS Jack at low gain
for instruments with high impedance pickups.
Inputimpedanceissetfor1MΩtosuitbassgui-
tars, mandolins etc.
PHANTOM POWER
QUICK START:
48V Phantom Power is available for microphones.
P48 button activates Phantom Power after a 10
second soft ramp-up time. Phantom Power is only
available from the XLR MIC input.
MORE DETAIL:
The Prodigal is capable of supplying 48V Phan-
tom Power to microphones or other microphone-
level devices.
P48 button activates the Phantom Power circuit
which, after a 10 second soft ramp-up time,
makes +48 Volts DC available on pins 2 and 3 of
the Rear Main XLR Input, via a DC supply network
withanimpedanceof6.8kΩperpin.
Whenever the P48 button is switched on, its LED
will glow, indicating that P48 is ready to be sup-
plied to the XLR. However, Phantom Power will
only be supplied to the XLR when the input is
switched to MIC, and is not available when the
input is switched to LINE. Phantom Power is never
available from the Front Jack inputs.
The activation of Phantom Power does not affect
the impedance of the microphone input.
MAIN INPUT SELECTORS

13
QUICK START:
All input signals pass through the Preamplifier.
IN knob provides 30dB of variable gain. Adjust
so the Input Meters show as much signal level as
possible without danger of clipping.
PAD button cuts input signal by 20dB. Use when
the IN knob is all the way down but you still have
too much level.
Ø REV Phase Reverse swaps the hot and cold pins
of your input source. Not used a lot, but helps
correct phase errors between microphones etc
that do not agree.
Hz knobs control bandwidth at the Preamplifier’s
output. Normally left at 20Hz-20kHz unless you
want to cut some highs or lows.
MORE DETAIL:
After input switching, all signals pass through the
Preamplifier and receive various levels of amplifi-
cation depending on the input selected. A signal
of suitable amplitude can then be passed to the
following circuitry.
IN knob provides an additional 30dB of variable
gain. A good start is to adjust the signal so the In-
put Meters show as much level as possible with-
out danger of clipping. A generous signal level at
this point will give you the best signal to noise
performance, and also more flexibility with dy-
namics processing in the De-Esser and Compres-
sor sections downstream.
PAD button lowers the level of the input signal
by 20dB before it hits the Preamplifier, which
helps deal with loud sources. Use when the IN
knob is all the way down but you still have too
much level.
Ø REV Phase Reverse also resides before the Pre-
amplifier input. This button swaps the hot and
cold pins of your input source (pins 2 and 3 of
the XLR, Tip and Ring of the Jack), which turns the
waveform upside down. Helps correct phase er-
rors between microphones etc that do not agree,
such as the top and bottom mic on a snare drum.
Hz knobs control bandwidth at the Preamplifier’s
output. Normally 20Hz-20kHz, lower cut-off is
sweepable up to 200 Hz and upper cut-off down
to 2kHz to help eliminate any undesirable out-
band audio prior to EQ and dynamics processing.
No more thumpy mandolins and tinkly tubas.
Physics tells us that less bandwidth also means
less noise, and usually you get a tighter sound
to boot.
TECH:
The Preamplifier is an extremely low current, low
noise, balanced transistor design. Transistors
are hand matched for best performance, and the
overall sound is silky and smooth.
Inputs to the Prodigal are electronically balanced
and no audio transformers are used. Input imped-
ance and overall Preamplifier gain are different
for each Input Selector position, and switching
is done via relays to reduce the signal path and
maintain high quality. No audio passes through
the Input Selector Switch.
IN control provides 30dB of user adjustable
gain. A linear potentiometer controls specially
designed logarithmic circuitry to give accurate
and even adjustment throughout the whole 30dB
range.
PAD button cuts the input signal by 20dB before
it hits the Preamplifier.
Ø REV Phase Reverse also resides before the Pre-
amplifier input. This button swaps pins 2 and 3
of the XLR, and Tip and Ring of the Jack.
Hz control sets bandwidth at the Preamplifier’s
output, and are marked according to the -3dB
down point. Lower cut-off is adjustable from
20Hz to 200 Hz, and upper cut-off is adjustable
from 2kHz to 20kHz. Roll off is 12dB per octave,
bessel, under-damped by 1dB at the upper and
lower knee.
PREAMPLIFIER

14
QUICK START:
Frequency response can be tailored using the EQ,
DE-MUD and AIR filters.
• EQ:
Hz knob selects any frequency between 100Hz
and 10kHz.
-dB+ knob cuts or boosts the selected frequency
by up to 10dB.
IN button activates the EQ. When button is out,
this section is bypassed. IN button does not af-
fect DE-MUD or AIR sections.
• DE-MUD and AIR:
DE-MUD filter produces a cleaner sounding take,
especially on microphones in a live room. Cuts
muddy yuck at 300Hz by 3dB. When button is
out, this section is bypassed.
AIR filter accentuates the edges of a sound by
boosting the airy high frequencies, adding defi-
nition, clarity and presence. When button is out,
this section is bypassed.
MORE DETAIL:
Following preamplification, frequency response
can be tailored using the EQ, DE-MUD and AIR
filters.
EQ consists of a single band of sweepable cut
and boost, for accentuating or suppressing im-
portant frequencies in a performance.
Hz knob selects any frequency between 100Hz
and 10kHz.
–dB+ knob cuts or boosts the selected frequency
by up to 10dB, with a roll-off of 12dB per octave
above and below. Q=1 is constant, so at plus or
minus 3dB the bandwidth is 1 octave. As the roll-
off slope remains constant with additional boost
or cut, tone adjustments never sound peaky or
notchy.
IN button activates the EQ. When button is out,
this section is bypassed. The IN button does not
affect DE-MUD or AIR sections.
DE-MUD button activates the DE-MUD filter, which
produces a cleaner sounding take, especially on
microphones in a live room. Response is a fixed
1 octave wide 3dB cut, centred at 300Hz. Not a
lot of music happens at 300Hz, but some rooms
are very peaky at that frequency and can make
recordings sound a little muddy. Such tracks can
also sum together unfavourably in a mix. Cut-
ting 300Hz on a vocal take is a popular move for
many engineers. When button is out, this section
is bypassed.
AIR button activates the AIR filter, which accen-
tuates the edges of a sound, adding definition,
clarity and presence. Helps push a vocal perfor-
mance forward in the stereo image. Response is
flat below 9kHz, up 1dB at 10kHz, and up 10dB
at 20kHz. In the signal chain, the AIR section is
positioned after the DE-ESSER and COMPRESSOR
so that their dynamics are not in danger of being
triggered by the boosted highs. When button is
out, this section is bypassed.
TECH:
The EQ section allows 10dB of cut or boost across
6.5 octaves from 100Hz to 10kHz. The filter type
is constant Q=1, and the roll-off is 12dB per oc-
tave above and below the selected frequency.
Constant Q of 1 means at plus or minus 3dB the
bandwidth is 1 octave, and at plus or minus 10dB
the bandwidth is slightly under 2 octaves.
DE-MUD filter produces a 1 octave wide 3dB cut,
centred at 300Hz.
AIR filter produces a response which is flat below
9kHz, up 1dB at 10kHz, and up 10dB at 20kHz.
EQUALISATION SECTION

15
QUICK START:
The De-Esser applies fast limiting to sibilant
“essy” content in the audio signal.
Hz knob. Set from 1kHz to 10kHz. During De-
Essing, frequencies above this setting are limit-
ed, and frequencies below are not. Start around
7kHz.
ESS knob. Clockwise sounds more “essy”, and an-
ticlockwise less. Start around the half-way mark
and go for what sounds natural.
IN button activates the De-Esser. When button is
out, this section is bypassed. Use it to compare.
LIMIT LED shows when the De-Esser is working,
and gets brighter with increased limiting. For a
detailed look, switch the Output Meter to DE-ESS
position.
MORE DETAIL:
Following the Equalisation Section is the Dynam-
ics Section, at the head of which is the De-Esser.
Microphones can have issues processing sibilant
content from the human voice, flutes and other
wind instruments, and this “essy” content can fre-
quently sound harsh and over-emphasised. The
De-Esser applies fast dynamic limiting to such
material to help reduce its level in comparison to
the main body of the performance, resulting in a
more natural sound.
Hz knob selects the frequency band in which the
De-Esser operates, and may be set anywhere be-
tween 1kHz and 10kHz. When De-Essing occurs,
frequencies above this setting will be affected,
and lower frequencies will not. Try to set this
control to just underneath the “essy” frequency,
so as to limit sibilance while leaving as much of
the main signal as possible unaffected. A suit-
able starting point might be about 7kHz, as most
“essy” sounds occur above that point. From there
you can rotate anticlockwise as required.
ESS knob controls how much sibilance gets
through to the output. Turning clockwise the pro-
gram will be more “essy”, and anticlockwise less
“essy”. A suitable starting point might be around
the half-way mark. In the background, the thresh-
old circuitry is constantly sampling, comparing,
and adjusting itself to the overall full-bandwidth
signal. The result is that once the ESS knob is
set, a comparatively proportional amount of de-
essing can be expected regardless of program
volume or dynamics. The goal is a result that
sounds natural, so beware of setting this control
too low and punching a hole in your highs.
IN button activates the De-Esser. When button is
out, this section is bypassed. Using this button
can also be a handy way of comparing the origi-
nal sound with the processed result.
LIMIT LED provides quick and handy feedback of
De-Esser operation. It activates after 1dB of gain
reduction, and gets brighter as more limiting oc-
curs. If detailed monitoring is required, the Out-
put Meter may be switched to DE-ESS position.
(See also OUT/COMP/DE-ESS Meter)
TECH:
The Prodigal De-Esser consists of a bandwidth re-
stricted FET limiter, with user controlled crosso-
ver point and threshold adjustment. In each Prod-
igal the FET transistors are hand matched so that
Left and Right channels operate identically. The
limiter action is soft knee, 20:1 ratio, 0.5mS at-
tack and 40mS release. Maximum “ess” reduction
is 22dB.
Hz control is a 12dB/octave crossover, sweepable
from 1kHz to 10kHz. The low band is bypassed
and the high band is sent to the limiter.
ESS control defines the threshold above which
limiting occurs. The range is all the way from
ground (MIN) to the power rails (MAX). A portion
of the full bandwidth signal is rectified and added
to the threshold voltage, so that the threshold
will be higher during louder passages. This helps
keep processing proportional during passages of
varying level.
Monitoring is available via LIMIT LED and Output
DE-ESS meter.
DE-ESSER

16
QUICK START:
The Compressor/Limiter reduces dynamic peaks
in program material.
INPUT knob. More input results in more compres-
sion. Start at around +10, and keep your Prodigal
input levels up.
COMPRESS knob controls both compression ra-
tio and threshold level. Choose a ratio and rotate
the INPUT knob to push more signal into com-
pression. Threshold levels are arranged so that
peaks are maintained around –12dBFS. Try 3:1
for guitars, 4:1 for vocals, 8:1 for bass, 16:1 for
snare drum, 20:1 for drum room.
ATTACK knob controls how quickly audio is
compressed. F=Fast and S=Slow. Fast is good for
bus limiting. Slower is less abrupt, and lets lead-
ing edges through. It can be hard to hear the dif-
ference so start at half rotation.
RELEASE knob controls how quickly the Compres-
sor restores itself. F=Fast and S=Slow. Try setting
RELEASE so the Compressor recovers from one
event just before it gets to the next. ie the next
vocal phrase, or the next bass guitar note. Start
with this knob at half rotation.
LIMIT LED shows when the Compressor/Limiter
is working, and gets brighter with increased lim-
iting. For a detailed look, switch the Output Me-
ter to COMP position.
LR LINK button links both the Left and Right
channel Compressors so that they operate in uni-
son, which is useful for stereo. Try to match the
settings on each channel, as there is no master,
and one side affects the other. Normally the LR
LINK button is not used.
IN button activates the Compressor/Limiter.
When button is out, this section is bypassed. Use
it to compare.
MORE DETAIL:
The Compressor/Limiter reduces dynamic peaks
in program material. It is very fast and uses a FET
transistor as its active element. Unlike some oth-
er FET compressors the Prodigal does not sound
squashed or crunchy when driven hard, but main-
tains a crystal clear transparency and warmth re-
gardless of the level of gain reduction.
The purpose of compression is to get a big fat
sound that can sit prominently in a mix. The
purpose of limiting is to prevent a sound you al-
ready like from running out of headroom. They
are really both the same thing, but when a small
amount is used to prevent bus clipping it is typi-
cally referred to as ‘Limiting’, and when a lot is
applied so that it changes the sound it is gener-
ally regarded as ‘Compression’.
INPUT knob controls how much signal is driven
into the Compressor/Limiter to be available for
gain reduction. More input results in more com-
pression, and turning this knob clockwise pro-
vides up to 25dB of additional level beyond what
is available from the channel bus.
COMPRESS knob simultaneously controls both
the compression ratio and the threshold level.
When a signal’s level exceeds the threshold, gain
reduction is applied to the whole signal accord-
ing to the ratio which has been selected, and the
amount by which the signal exceeds the thresh-
old. For instance, when the COMPRESS knob is
set to 20:1 a signal which exceeds the threshold
by 20dB would be reduced to a level which ex-
ceeds the threshold by only 1dB. At 1:1 there is
no compression action, and the output will equal
the input. The set thresholds vary with ratio and
have been carefully chosen so that comfortably
high levels are maintained throughout the signal
chain. Once a suitable ratio has been chosen, the
INPUT knob is used to manage how much of the
input signal is driven over the threshold and into
compression. In normal usage peaks are main-
tained at around –12dBFS on the Output Meter
when the Output Fader is at ‘0’. Try 3:1 for gui-
tars, 4:1 for vocals, 8:1 for bass, 16:1 for snare
drum, 20:1 for drum room limiting.
ATTACK knob controls how quickly the Compres-
sor snaps into action after a signal crosses the
threshold. F=Fast and S=Slow. Fast is 5uS, which
means a 20kHz sine wave will trigger less than
half way up its leading edge, which is great for
limiting of content with fast transients. Slower at-
tack times can make the compression action less
abrupt, and allow the first percussive edge of a
sound to pass through before compression takes
COMPRESSOR/LIMITER

17
place, which may be desirable for drums, guitar,
piano, etc. Slow is 2.5mS. It can be hard to hear
the difference so start at half rotation.
RELEASE knob controls how quickly the Compres-
sor restores itself after a gain reduction event.
F=Fast and S=Slow. (50mS to 1.35 Sec). If set too
fast the program can sound like it is pumping. If
set too slow the Compressor will not be ready for
the next event, and the program can sound tired
and squashed. In common usage the RELEASE
time would be set so the Compressor recovers
from one event just before it attends to the next.
For a vocal this might be the next phrase, and for
a bass guitar this might be the next note. Start
with this knob at half rotation.
LIMIT LED activates after 1dB of gain reduction,
and gets brighter as more limiting occurs, provid-
ing quick and handy feedback. If more detailed
monitoring is required, the Output Meter may be
switched to COMP position.
COMP Meter. Switch the Output Meter to COMP
to get quantifiable feedback of the limiting ac-
tion. When using the COMP Meter the –0dBFS LED
is always lit, and the amount of gain reduction is
displayed as a reverse solid bar.
LR LINK button is located in the Left COMPRESS/
LIMIT section, and its purpose is to link both the
Left and Right channel Compressors so they op-
erate in unison which can be useful for stereo
signals. When used in this mode, care should be
taken to match the settings on each channel as
there is no master channel and one side will in-
fluence the other. The ATTACK and COMPRESS
knobs remain independent, but once triggered
both Left and Right gain reduction elements and
RELEASE controls are linked and will compress
and release in unison. RELEASE time will be de-
termined by the faster of the two controls.
Another use of the LR LINK button is to use one
channel of the Prodigal as a side chain to trigger
gain reduction on the other channel. An example
would be running a music track through the Left
channel, with COMPRESS set to 1:1, and ATTACK
and RELEASE both full clockwise to Slow. All gain
reduction action would then be dictated by the
Right channel control settings. If the Right chan-
nel carries a speech signal, with say 6dB of gain
reduction, this would also reduce the Left chan-
nel by 6dB so the music would automatically duck
during speech and return to normal thereafter.
IN button activates the Compressor/Limiter.
When button is out, this section is bypassed. Us-
ing this button can also be a handy way of com-
paring the original sound with the processed re-
sult.
TECH:
The Prodigal Compressor/Limiter is very fast
and uses a FET transistor as its active control el-
ement. In each Prodigal the FET transistors are
hand matched so that Left and Right channels op-
erate identically. The limiter action is soft knee,
and maximum gain reduction is 22dB.
INPUT control provides up to 25dB of additional
level beyond what is available from the channel
bus.
COMPRESS control simultaneously adjusts both
the compression ratio and the threshold level.
For each compression ratio the corresponding
threshold level is outlined in the table below.
Levels are expressed in –dB Full Scale and cor-
respond to the Output Meter when the Output
Fader is positioned at ‘0’.
Threshold Levels in –dB Full Scale:
1:1 = N/A
2:1 = –34dBFS
3:1 = –26dBFS
4:1 = –22dBFS
8:1 = –17dBFS
16:1 = –15dBFS
20:1 = –14dBFS
With regard to the above thresholds and the soft
knee action of the limiter; in normal usage and
for any ratio between 3:1 and 20:1 an input signal
of around –2dBFS could be expected to produce
an output signal of around –12dBFS (ie, 10dB of
gain reduction).
ATTACK control range is from 5 microseconds to
2.5 milliseconds.
RELEASE control Range is from 50 milliseconds
to 1.35 seconds.
Monitoring is available via LIMIT LED and Output
COMP Meter.

18
QUICK START:
The Output Fader is the final level control to the
XLR Output and the Monitor Input.
OUT knob default position is ‘0’. When channel is
notinusesetto‘∞’tomuteoutput.
DUAL MONO OUT button turns Left and Right
signals into a Mono mix on both outputs.
MORE DETAIL:
The Output Fader is the final level control in the
Prodigal Channel Strip, and determines the bus
level to the Main XLR Output and the Prodigal
Monitor Station Input.
OUT knob is the Output Fader which provides
between +6dB of gain all the way down to a full
channel mute. Normal operating position is ‘0’
to provide unity gain from channel bus to mix
bus. Can be adjusted up or down when using the
Compressor/Limiter if ‘make-up’ gain is needed.
Whenchannelisnotinusesetto‘∞’tomutethe
output.
DUAL MONO OUT button turns stereo Left and
Right into a Mono mix on both outputs. The mix
is monoed after the OUT knob, so each fader can
be used to control its own Mono level.
TECH:
The Prodigal employs the standard that when two
signals are monoed they are first cut by 6dB and
then added together, which more often than not
raises their combined level by the same 6dB. So
when switching between stereo and mono there
is generally no discernible change in level, nor
decrease in available headroom due to the sum-
ming of the two busses.
OUTPUT FADER

19
QUICK START:
The Input Meter displays the level after the Input
Gain (IN knob) in –dBFS.
A solid bar of VU indicates the average level on
the bus, and Peak Dot above it indicates available
headroom.
Adjust IN knob so the Input Meter shows as much
signal level as possible without danger of clip-
ping.
MORE DETAIL:
The Input Meter is a 16 stage LED level meter
marked in –dB Full Scale (–dBFS). It displays the
signal level on the channel bus after the Input
Gain control (IN knob) and before the Bandwidth,
EQ and Dynamics stages (see block diagram else-
where in this document). It is recommended that
the IN knob be adjusted so the Input Meter shows
as much level as possible without danger of clip-
ping. A generous signal level at this point will
give you the best signal to noise performance,
and also more flexibility with dynamics process-
ing in the De-Esser and Compressor sections lat-
er.
The Input Meter displays a solid bar of VU with a
Peak Dot floating above it. VU indicates the aver-
age signal level on the bus, and ballistics reflect
the VU standard of 300mS Full Scale attack and
300mS decay. Peak Dot indicates the amount
of headroom available. Attack is instantaneous,
with 3 second hold and 18dB/sec decay.
Nominal channel bus level is –18dBFS. When the
Output Fader is set to ‘0’ this corresponds to a
mix bus level on the Output Meter of –18dBFS,
which in turn corresponds to an output between
pins 2 & 3 of the Main XLR Out of +4dBu (–10dBV,
switchable).
INPUT METER OUT/COMP/DE-ESS METER
QUICK START:
The Output/Compressor/De-Esser Meter is a
rotary switch enabled, tri-purpose level meter
marked in –dBFS.
OUT Meter displays the signal level after the Out-
put Fader (OUT knob).
A solid bar of VU indicates the average level on
the bus, and Peak Dot above it indicates available
headroom.
COMP Meter directly displays Compressor/Lim-
iter gain reduction as a reverse solid bar. –0dBFS
LED is always lit.
DE-ESS Meter directly displays De-Esser gain re-
duction as a reverse solid bar. –0dBFS LED is al-
ways lit.
MORE DETAIL:
The Output/Compressor/De-Esser Meter is a tri-
purpose 16 stage LED level meter marked in –dB
Full Scale (–dBFS). A rotary switch enables selec-
tion of the various sources.
OUT displays the signal level on the mix bus af-
ter the Output Fader (OUT knob) and before the
Main XLR Output and the Prodigal Monitor Input
(see block diagram elsewhere in this document).
The Output Meter displays a solid bar of VU with
a Peak Dot floating above it. VU indicates the av-
erage signal level on the bus, and ballistics re-
flect the VU standard of 300mS Full Scale attack
and 300mS decay. Peak Dot indicates the amount
of headroom available. Attack is instantaneous,
with 3 second hold and 18dB/sec decay.
Nominal mix bus level is –18dBFS, which corre-
sponds to an output between pins 2 and 3 of the
Main XLR Out of +4dBu (–10dBV, switchable).
COMP displays a direct representation of Com-
pressor/Limiter gain reduction activity, with no
artificial ballistics applied. In this setting the
–0dBFS LED is always lit, and the amount of limit-
ing is displayed as a reverse solid bar.
DE-ESS displays a direct representation of De-Es-
ser gain reduction activity, with no artificial bal-

20
listics applied. In this setting the –0dBFS LED is
always lit, and the amount of limiting is displayed
as a reverse solid bar.
Before tracking is commenced it is recommend-
ed that the Main XLR Output of the Prodigal and
the Line or Aux level (NOT MIC) Input Stage of
your DAW or other recording device be aligned
so that the Prodigal Output Meter and the re-
cording channel input meter both agree. When
they are thus aligned, your gain structure will be
optimised and the Prodigal Output Meter will be
semi-redundant, as it is now just as useful to use
the recording channel meter to monitor overall
level. That means that during tracking it is pos-
sible to make COMP or DE-ESS the view of choice,
switching to look at the Output Meter only when
necessary.
PEAK LED INDICATORS
QUICK START:
There are two Peak LEDs per channel to indicate
clipping. If either LED glows, lower the signal lev-
el upstream.
MORE DETAIL:
There are two Peak LED Indicators on each Prodi-
gal channel bus which independently warn when
the audio signal has run out of headroom, and
turn on 4dB before clipping either the positive or
negative rail. They respond to levels immediately
after the EQ section, and Compressor/Limiter
and AIR filter sections (see block diagram else-
where in this document). The Peak LEDs respond
directly to the audio signal level, and no ballis-
tics are applied. If either LED glows it is advisable
to lower the signal level somewhere upstream of
that LED to avoid channel bus clipping.