NTS VF Series User manual

VF
R
VF150
CH ACH A
POWER
-15
-10LIMITERPRO POWER -15 - 10 LIMITE R PRO 0
-1
-3
-5
-7
-10
-12
-16
-20
-40
-80 dB
0
-1
-3
-5
-7
-10
-12
-16
-20
-40
-80 dB CH BCH B
R
PROFE SSIO NAL PO WER AM PLIFI ER
CH A CH B
POWER POW ER
-15 -15
-10 -10 LIMITER L IMITERPRO PRO
0
-1
-3
-5
-7
-10
-12
-16
-20
-40
-80 dB 0
-1
-3
-5
-7
-10
-12
-16
-20
-40
-80 dB
VF300
R
PRO FESS IONA L POWE R AMPL IFIE R
CH A CH B
POWER POW ER
-15 -15
-10 -10 LIMITER L IMITERPRO PRO
0
-1
-3
-5
-7
-10
-12
-16
-20
-40
-80 dB 0
-1
-3
-5
-7
-10
-12
-16
-20
-40
-80 dB
R
PRO FESS IONA L POWE R AMPL IFIE R
CH A CH B
POWER POW ER
-15 -15
-10 -10 LIMITER L IMITERPRO PRO
0
-1
-3
-5
-7
-10
-12
-16
-20
-40
-80 dB 0
-1
-3
-5
-7
-10
-12
-16
-20
-40
-80 dB
R
PRO FESS IONA L POWE R AMPL IFIE R

Important Precautions
21. Ser vice Inf or mation. Equipment
should be ser viced by qualifi ed service
perso nnel when:
A. The power supp ly cor d or the pl ug
has been damaged;
B. Obj ects have fal len, or liquid has
been sp illed into the equipment;
C. The equipment has been exposed to
rain;
D. The equipment does not appear to
operate normally, or exhibits a marked
change in per formance;
E. The equipment has been dropped,
or the enclosu re damaged.
This symbol is used to alert the operator
to follow important operating and pre
cautions detailed in documentation.
This symbol is used to warn operators
that uninsulated" dangerous voltages"
are present within the equ ipme nt
enclo-
sur e
tha t may po s e a risk
of el ec tric shock.
1. Save the carton and packin g material even
if th e equipment has arr ived in good con-
diti on. Should you ever need to ship th e unit,
use only th e original fa ctor y packing.
2. Read all documentation before operatin g
your equipment. Reta in all documentati on
for future re fe re nce.
3. Fol low al l instruct ions pr inted on uni t
chassis for proper operati on.
4. Do not spill wate r or oth er liquids into
or
on the unit, or ope rate the unit
while
sta nding in liquid.
5. Make sure power outl ets confo rm to
the
power requirements liste d on th e back of
the unit.
6. Do not use the unit if th e electri cal
power
cord is fra yed or broken. The power
supply
cords sho ul d be routed so that they are
not likely to be walked on or pinched by
ite ms placed upon or against th em,
payin g
particular attention to cords and plugs,
convenience re ceptacles, and th e point
where they exit from the appliance.
7. Always operate the unit with the AC
ground wire connected to the electrical
system gr ound . Precaut ions shoul d
be
taken so that the means of groundi ng
of a piece of equipment is not defe ated.
8. Mains volta ge must be correct and the
same as that pri nted on the rear of the unit.
Damage caused by connection to impro per
AC voltage is not covered by any warra nty.
9. Have gain contr ols on amplifiers tu rn ed
down duri ng power-u p to pre vent
speaker
damage if there are high signal levels at
the inputs.
10. Power down and disconnect units
from mains voltage before making
conn ect ions.
!
11. Never hol d a power switch in the
"ON" position if it won' t stay there itse lf!
12. Do not use th e unit near sto ves, heat
registe rs, radiators, or other heat prod
ucing devices.
13. Do no t block fan int ake or exha ust
ports. Do not operate equipment on a
surfa ce or in an environment which may
impede the nor mal flow of air ar oun d
the unit, such as a bed, rug, weather
sheeT, carpet, or completely
enclosed
rack. If the unit is used in an extremely
dusty or smok y en viron ment, the unit
shoul d be per iodi cal ly“blown free”
of foreign matter.
14. Do not re move th e cover. Removing
the cover will exp ose yo u to potentially
dangerous vo ltages. Th ere are no user
serviceable parts inside.
15. Connecting amp lifier outputs to
osc illosc opes or other test equipment
whi le the amplifier is in bridged mode
may damage both the am pl ifier and
test equipment!
16. Do not drive the inputs with a si gnal
level greater than that required to
dri ve
equipment to full output.
17. Do not connect the inputs / outputs
of am pl ifiers or cons ol es to any ot her
volta ge sourc e, such as a batt ery,
mains
sou rce, or power sup ply, regardless of
wheth er the amplifie r or console is tu rn ed
on or off.
18. Do not ru n th e outp ut of any amplifi er
channel back int o anot her channel 's
input. Do not parallel- or seri es-connect
an amplifier output with any other am
plifi er output. is not resp onsi ble
for damage to lou ds pe aker s.
period of time.
19. Do not ground any re d (" hot") termin al.
Nev er con nec t a "hot " (red) out put to
ground or to another "hot" (red) output!
20. Non-u se periods. The power cord of
equipment should be unplugged from
the outlet when left unuse d for a long
R

Power Amplifier Owner's Manual
Table of Contents
Appendix A Specifications
Appendix B VF Block Diagram
Appendix C B Power Amplifier - Special Functions
Introduction
Unpacking
Installation and Mounting
Front Panel
Rear Panel
Operation
Connecting Inputs
Connecting Outputs
Mode Selection
Stereo /Parallel/Bridged Mono Connections
Protection Features
User Precautions
Speaker Protection
Maintenance
User Responsibility
Service and Repair
3
3
3
4
5
6
6
6
7
10
11
12
12
13
13
13
Page 1
S E R I E S
VF
R
VF Series Power Amplifiers
MODELS VF150, VF300, VF600, VF800
R

MONO
BRIDG E
A B
USE ONLY WIT H A 250V FUS E
PUS H
12 3
PUS H
12 3
FUSE
(220 V/4A)
AC INP UT
(220 V/60H z)
L
O
C
K
L
O
C
K
CH BCH A OU TPU TS
SENS ITIVI TYFILTE R
MODE
STERE O
BRIDG E
PARAL LEL
GROUND
HI PASS
BY PAS S
LOW PAS S
1.44V
1.0V
0.775 V
OFF
ON
INP UT S
CH A CH B
PINOU T
+
P2
TIP
P3
RNG SL V
P1
XLR
PINOUT
1+ 1-
POS NEG
CH B
PINOUT
1+ 1-
POS NEG
CH A
2+ 2-
POS NEG
CH B
1+
POS
2+
NEG
BRIDGE
Page 2
VF300, VF600, VF800 ViewFront
Front width 482mm
Front
height
3.5"
88mm
VF150 Front View
Front width 482mm
Front
height
1.75"
44mm
Rear & Side Views
Speakon output model shown
44mm
364mm
VF150
384mm
88mm
430mm
VF300
VF600
VF800
S E R I E S
VF
R
CH A CH B
POWER
-15
-10LIMIT ERPRO POWER - 15 -10 LI MITER PR O 0
-1
-3
-5
-7
-10
-12
-16
-20
-40
-80 dB
0
-1
-3
-5
-7
-10
-12
-16
-20
-40
-80 dB
VF150
R
PRO FESS IONAL POWER A MPLI FIER
CH A CH B
POWER P OWER
-15 -15
-10 -10 LIMIT ER LIMIT ERPRO PRO
0
-1
-3
-5
-7
-10
-12
-16
-20
-40
-80 dB 0
-1
-3
-5
-7
-10
-12
-16
-20
-40
-80 dB
R
PR OF ES SI ON AL P OW ER A MP LI FI ER
VF300
MODE GR OUND
FILTER
120Hz120Hz
SUBWO OFER FU LL RANG E SATELLI TE
INPUT IM PEDAN CE:
20K BAL ANCED
10K UNBA LANC ED
CH A
L
O
C
K
L
O
C
K
OUT PUTS
INP UTS
CH B
CH A
CH B
AC INP UT
(220 V/60H z)
BRIDG E
A
MONO
B
CH A
CH B
STERE O
PARALL EL
BRIDG E
1 2 3 4 5 6
ON
OFF
87
PINO UT
+
P2
TIP
P3RNG
SLV P1
XLR
PINO UT
CH A
1+1-
POS NEG
1+
POS
CH B
2+2-
POS NEG
BRIDG E
2+
NEG
PINO UT
1+1-
POS NEG
CH B
PUS H
12 3
1 2 3 4 5 6 7 8
ON
USE ONLY WIT H A 250V FUS E
FUSE
(220 V/8A )
SERIA L NO.:
MADE I N CHINA
PUS H
12 3
VF Series Power Amplifiers
MODELS VF150, VF300, VF600, VF800
R

Page 3
Introduction
Congratulations on your purchase of a new VF Series professional power amplifier, and thank you for
your confidence in products. You are among the growing number of audio professionals who
have made one of Southern Africa's leading suppliers of professional and commercial/industrial
audio systems.
For your safety, please read the Important Precautions section before installing and operating the amplifier.
The VF Series is based on t he same advanced circuit topologies that h ave made amplifiers
the choice of professionals.VF Series amplifiers are designed for high operating effici and accurateency
sonic performance across the full audio bandwidth, even under stressful conditions. Internal components
are the finest available, and key subassemblies are pre-tested before final assembly. Finally, each amplifier
is "burned in" and thoroughly tested (using precision audio test equipment) before shipping. In addition,
all VF Series amplifiers incorporate Exclusive Tour Class protection features to safeguard both internal
circuitry and connected loud speakers.This proven combination of advanced design, quality construction,
and compr eh ensive circuit prot ec tions is your guarantee o f fa il -safe reliabili ty. You can depend o n
consistent, stable performance .
Unpacking
Please inspect the amplifier carefully immediately after unpacking. If you find any damage, notify your
supplier/dealer immediately. Be sure to save the carton and all packing materials. If you ever need to
ship the unit back to or an authorized service centre, you should use only the original factory
packaging.
Installation and Mounting
The VF15 0 a mplifie r i s 1 -rack-space high and the rest VF30 0, VF600 ,VF800 are 2-rac k-spa ces high.
All mount in panel mounti ng holes are provide d standar d 1 9- inch racks. Four front on eac h amplifier.
Rear mou nt ing use of rear supports is highl y recommears giv e a dd itional support, and ended in all
mobile and touring sound sys te ms.
S E R I E S
R
VF
R
R
RR
R
R
VF Series Power Amplifiers
MODELS VF150, VF300, VF600, VF800
R

Page 4
S E R I E S
1. Rack Mounting Ears.
Two front panel mounting holes are provided on each mounting ear.
3. Input Attenuators.
Attenuators are adjustable and allow for precise setting of input gain.
4. Protect LED.
Indicates that the channel is in Protect mode (speakers disconnected by output relay).
5. Limiter LED.
Illuminates at the clipping threshold. Continuous illumination also indicates that ACL (Active Clip
Limiting) protection circuitry is engaged.
7. Level Indicator.
6. Power LED.
Indicates that AC power is connected and the amplifier is turned on.
8. AC Power Switch
This is the main Power switch.Press to turn on the amplifier.
CH A CH B
POWER P OWER
-15 -15
-10 -10 LIMIT ER LIMITERPRO PRO
0
-1
-3
-5
-7
-10
-12
-16
-20
-40
-80 dB 0
-1
-3
-5
-7
-10
-12
-16
-20
-40
-80 dB
123 4 5 6 78 3
123 4 5 6 78 3
Front Panel
VF
R
CH A CH B
POWER
-15
-10LIMIT ERPRO POWER - 15 -10 LIMIT ER PRO 0
-1
-3
-5
-7
-10
-12
-16
-20
-40
-80 dB
0
-1
-3
-5
-7
-10
-12
-16
-20
-40
-80 dB
VF150
R
PRO FESS IONA L POWER A MPLI FIER
R
PR OF ES SI ON AL P OW ER A MP LI FI ER
VF300
VF Series Power Amplifiers
MODELS VF150, VF300, VF600, VF800
R
2.Air cooling windows
This part is the air cooling window. Don't obstruct it.

Page 5
S E R I E S
Rear Panel
9.Output Connectors
B s e r ies a m pli f i e r s h a v e two d i ffe r e n t out p u t co nne c t o r s, o n e is b i n d ing p ost, an o t h e r is s p eako n .
Connection to the binding post can be made with bare wire, banana plugs, or spade lug terminations.
Make connections to both the channel A and channel B terminals for stereo or parallel mode, or a single
co nnec t ion acro s s the re d ("h o t") te rmin als onl y o f chan nels A a n d B f or bri dged m o no mod e. Usi ng
speakon-type speaker cables,make connections to both the channel A a nd channel B connectors for
stereo or parallel mode.Or to the bridged mode connector for bridged mono mode.
10- 11. Bal anced 1/ 4" (Jack) & XL R Input Connect ors.
These connectors accept input signals on balanced Jack and XLR input plugs. See the figure on the next
page for informat ion o n polari ty. Conne ctors for each cha nnel in p arallel. The u nused connectors are
ma y b e u sed for " loop t hrough" c onnection t o o ther a mp lifiers.
NOTE: Unbal an ce d "Tip/ Slee ve" pl ugs may be used wi th the bal an ce d Jac k "Tip/ Ring/ Slee ve" co nnector s. The
"ring" ter minal or neg at ive inpu t wi ll be co nnec ted to gr ou nd inter nal ly. When using three -po le ('ster eo ') Jac k
con nec tor s, make sur e that the ring con nec tion is made ei ther to the col d (-) out put of the sour ce equi pm ent,
or to ground . Incor rect connect ions may caus e a 6dB loss in level .
MONO
BRI DGE
A B
USE O NLY WITH A 250V F USE
PUSH
12 3
PUSH
12 3
FUS E
(22 0V/4A )
AC IN PUT
(22 0V/ 60H z)
L
O
C
K
L
O
C
K
CH BCH A OUTP UTS
SEN SIT IVI TYFIL TER
MODE
STE REO
BRI DGE
PAR ALLE L
GROUND
HI PA SS
BY PA SS
LOW PA SS
1.4 4V
1.0 V
0.7 75V
OFF
ON
INPUTS
CH A CH B
PIN OUT
+
P2
TIP
P3
RNG S LV
P1
XLR
PINO UT
1+ 1-
POS N EG
CH B
PINO UT
1+ 1-
POS N EG
CH A
2+ 2-
POS N EG
CH B
1+
POS
2+
NEG
BRIDGE
13
14
12
9
16
11
10
15
MOD E GROUND
FILTER
120H z120H z
SUB WOOFE R FULL RA NGE SATEL LITE
INPU T IMPED ANCE:
20K BA LANC ED
10K UN BALA NCED
CH A
L
O
C
K
L
O
C
K
OUTPUTS
INPUTS
CH B
CH A
CH B
AC INPUT
(220V/60Hz)
BRI DGE
A
MON O
B
CH A
CH B
STE REO
PARA LLEL
BRI DGE
1 2 3 4 5 6
ON
OFF
87
PIN OUT
+
P2
TIP
P3RNG
SLV P1
XLR
PIN OUT
CH A
1+1-
POS N EG
1+
POS
CH B
2+2-
POS N EG
BRI DGE
2+
NEG
PIN OUT
1+1-
POS N EG
CH B
PUSH
12 3
12345678
ON
USE O NLY WITH A 250V F USE
FUSE
(220V/8A)
SER IAL NO. :
MADE IN CHINA
PUSH
12 3
16
9
10 13 15
11 14
R
VF
VF Series Power Amplifiers
MODELS VF150, VF300, VF600, VF800
R

Page 6
S E R I E S
TIP-POSITIVE（+）
RING-NEGATIVE（-）
SLEEVE-GROUND（ ）
+
-
1-GROUND（ ）
3-N EGATIV E（-）
2-P OSITIVE （+）
13. Mode Selection Switch.
This recessed, three-position switch configures the amplifier for Stereo,
Parallel or Bridged Mono Mode
operation. Amplifiers are factory-
configured for Stereo Mode. See and the section on Mode Selection
for more information.
12.Input sensitivity selector
For B-300,B-2200this selector allows you to choose the input sensitivity
0.775v,1.00v,1.44v.
14.Filter 120Hz select:
Subwoofer,Fullrange,Satellite
15.Grounding selector
Insulates Mains Earth from electronic ground.This feature eliminates earth
loops that may cause 50Hz noise/hum on your system.
Operation
Connecting Inputs.
Use either the XLR or 1/4-inch Jack input connectors on the rear to supply audio signals to your VF
Series amplifier. Both connectors accept balanced and unbalanced audio connections. (The
VF Series amplifiers are configured standard with "Pin 2 hot"on XLR inputs. Please note that a min-
ority of amplifier manufacturers configure their designs with "Pin 3 hot"). The unused connector may
be used to daisy-chain the audio inputs to another amplifier input. For more information, see the
section on Balanced 1/4" (Jack) & XLR Input Connector, Input XLR Polarity, and Input Sensitivity.
Connecting Outputs.
Speakers are connected using output binding posts or speakon connectors.For more information,
see the Output Connector and Mode selection section.
R
VF
R
VF Series Power Amplifiers
MODELS VF150, VF300, VF600, VF800
R
16. Fan Outlet Grills.
VF Series amplifiers are cooled by two, rear-mounted fans. Cool air flows over the heat sinks and
exhausts through the front grills. Make sure these outlets remain clear to allow unrestricted air flow.

Page 7
S E R I E S
Mode Selection
The three-position, recessed Mode Select switch (located on the rear panel) configures the amplifier for either
Stereo, Parallel or Bridged Mono Mode. Amplifiers are factory-configured for Stereo
Mode.
Stereo Mode
In Stereo Mode, both channels operate independently, with their input attenuators controlling their respective
levels. Signal at Channel A's input produces output at Channel A's output, while signal at Channel B's input
produces output at Channel B's output. Recommended minimum nominal load impedance for stereo oper-
ation is 4 ohm per channel. Either the 1/4" (Jack) input or the XLR input may
be used.
Parallel Mode
When set to Parallel Mode, a signal applied to Channel A's input will be amplified and appear at outputs for both
Channels A & B. Either the 1/4" (Jack) input or the XLR input on Channel A may be used.Recommended minimum
nominal load impedance for parallel mode operation is 4ohm per channel.
Bridged Mono Mode
Bridged Mono Mode straps both amplifier channels together to make a very powerful, single-channel mono
block amplifier. One channel "pushes" and the other "pulls" equally, doubling the powe r over that of either channel
alone. Signal is applied to the Channel A input only. Both attenuators are used to control signal level; in addition,
both must be adjusted to the same setting. Either the 1/4" (Jack) or XLR input may be used.
NOTE: The channel B input connectors (XLR and/or Jack) may be used to "loop thru" the channel A signal when
in parallel or bridged mono mode.
Use extreme caution when operating the amplifier in Bridged Mono Mode. Never ground either side of
the speaker cable when the amplifier is in Bridged Mono Mode; both sides are "hot." If an output patch panel
is used, all connections must be isolated from each other and from the panel.
The recommended minimum
nominal load impedance in the Bridged Mono Mode is 8 ohms, which is the equivalent to driving both channels
separately at 4 ohms. Driving bridged loads of less than the recommended minimums will activate the
IGM
circuitry, resulting in a loss of power, and may also lead to a thermal protect condition.See figures on pages
8 & 9 Showing output connection information.
Connecting amplifier outputs to oscilloscopes or other test equipment while the
amplifier is in bridged mode may damage both the amplifier and test equipment!
!
VF
R
VF Series Power Amplifiers
MODELS VF150, VF300, VF600, VF800
R

MONO
BRID GE
A B
USE ON LY WITH A 250V FU SE
PUSH
12 3
PUSH
12 3
FUS E
(22 0V/4A )
AC IN PUT
(22 0V/6 0Hz)
L
O
C
K
L
O
C
K
CH BCH A OUTPUTS
SEN SITI VITYFILT ER
MOD E
STER EO
BRID GE
PARA LLEL
GROUND
HI PAS S
BY PAS S
LOW PA SS
1.44 V
1.0V
0.77 5V
OFF
ON
INPUTS
CH A CH B
PINO UT
+
P2
TIP
P3
RNG S LV
P1
XLR
PINOU T
1+ 1-
POS NE G
CH B
PINOU T
1+ 1-
POS NE G
CH A
2+ 2-
POS NE G
CH B
1+
POS
2+
NEG
BRIDGE
MONO
BRID GE
A B
USE ON LY WITH A 250V FU SE
PUSH
12 3
PUSH
12 3
FUS E
(22 0V/4A )
AC IN PUT
(22 0V/6 0Hz)
L
O
C
K
L
O
C
K
CH BCH A OUTPUTS
SEN SITI VITYFILT ER
MOD E
STER EO
BRID GE
PARA LLEL
GROUND
HI PAS S
BY PAS S
LOW PA SS
1.44 V
1.0V
0.77 5V
OFF
ON
INPUTS
CH A CH B
PINO UT
+
P2
TIP
P3
RNG S LV
P1
XLR
PINOU T
1+ 1-
POS NE G
CH B
PINOU T
1+ 1-
POS NE G
CH A
2+ 2-
POS NE G
CH B
1+
POS
2+
NEG
BRIDGE
MONO
BRID GE
A B
USE ON LY WITH A 250V FU SE
PUSH
12 3
PUSH
12 3
FUS E
(22 0V/4A )
AC IN PUT
(22 0V/6 0Hz)
L
O
C
K
L
O
C
K
CH BCH A OUTPUTS
SEN SITI VITYFILT ER
MOD E
STER EO
BRID GE
PARA LLEL
GROUND
HI PAS S
BY PAS S
LOW PA SS
1.44 V
1.0V
0.77 5V
OFF
ON
INPUTS
CH A CH B
PINO UT
+
P2
TIP
P3
RNG S LV
P1
XLR
PINOU T
1+ 1-
POS NE G
CH B
PINOU T
1+ 1-
POS NE G
CH A
2+ 2-
POS NE G
CH B
1+
POS
2+
NEG
BRIDGE
Page 8
S E R I E S
AA
or
Stereo Mode Connections
(Speakon Output Connectors)
Parallel Mode Connections
(Speakon Output Connectors)
Bridged Mono Mode Connections
(Speakon Output Connectors)
2+
2-
1+
1-
Speaker + to PIN 1+
Speaker - to PIN 2+
2+
2-
1+
1-
Speaker + to PIN 1+
Speaker - to PIN 1-
2+
2-
1+
1-
Speaker + to PIN 1+
Speaker - to PIN 1- AA
B
or
or
BRIDGED/MONO
B
+
+
B
+
A
AA
or
+
B
+
A
VF
VF
VF Series Power Amplifiers
MODELS VF150, VF300, VF600, VF800
R

Page 9
S E R I E S
VF
R
MODE G ROUN D
FILTE R
120H z120H z
SUBW OOFER F ULL RAN GE SATELL ITE
INPU T IMPED ANCE:
20K BA LANCE D
10K UN BALAN CED
CH A
L
O
C
K
L
O
C
K
OUTPUTS
INPUTS
CH B
CH A
CH B
AC IN PUT
(22 0V/60Hz)
BRID GE
A
MONO
B
CH A
CH B
STER EO
PARAL LEL
BRID GE
1 2 3 4 5 6
ON
OFF
87
PIN OUT
+
P2
TIP
P3RNG
SLV P1
XLR
PIN OUT
CH A
1+1-
POS NE G
1+
POS
CH B
2+2-
POS NE G
BRID GE
2+
NEG
PIN OUT
1+1-
POS NE G
CH B
PUSH
12 3
12345678
ON
USE ON LY WITH A 250V FU SE
FUS E
(22 0V/8A)
SERI AL NO.:
MAD E IN CHIN A
PUSH
12 3
MODE G ROUN D
FILTE R
120H z120H z
SUBW OOFER F ULL RAN GE SATELL ITE
INPU T IMPED ANCE:
20K BA LANCE D
10K UN BALAN CED
CH A
L
O
C
K
L
O
C
K
OUTPUTS
INPUTS
CH B
CH A
CH B
AC IN PUT
(22 0V/60Hz)
BRID GE
A
MONO
B
CH A
CH B
STER EO
PARAL LEL
BRID GE
1 2 3 4 5 6
ON
OFF
87
PIN OUT
+
P2
TIP
P3RNG
SLV P1
XLR
PIN OUT
CH A
1+1-
POS NE G
1+
POS
CH B
2+2-
POS NE G
BRID GE
2+
NEG
PIN OUT
1+1-
POS NE G
CH B
PUSH
12 3
12345678
ON
USE ON LY WITH A 250V FU SE
FUS E
(22 0V/8A)
SERI AL NO.:
MAD E IN CHIN A
PUSH
12 3
MODE G ROUN D
FILTE R
120H z120H z
SUBW OOFER F ULL RAN GE SATELL ITE
INPU T IMPED ANCE:
20K BA LANCE D
10K UN BALAN CED
CH A
L
O
C
K
L
O
C
K
OUTPUTS
INPUTS
CH B
CH A
CH B
AC IN PUT
(22 0V/60Hz)
BRID GE
A
MONO
B
CH A
CH B
STER EO
PARAL LEL
BRID GE
1 2 3 4 5 6
ON
OFF
87
PIN OUT
+
P2
TIP
P3RNG
SLV P1
XLR
PIN OUT
CH A
1+1-
POS NE G
1+
POS
CH B
2+2-
POS NE G
BRID GE
2+
NEG
PIN OUT
1+1-
POS NE G
CH B
PUSH
12 3
1 2 3 4 5 6 7 8
ON
USE ON LY WITH A 250V FU SE
FUS E
(22 0V/8A)
SERI AL NO.:
MAD E IN CHIN A
PUSH
12 3
Parallel Mode Connections
or
B
Bridged Mono Mode Connections
or
2+
2-
1+
1-
Speaker + to PIN 1+
Speaker - to PIN 2+
or
or
B B
B
2+
2-
1+
1-
Speaker + to PIN 1+
Speaker - to PIN 1-
2+
2-
1+
1-
Speaker + to PIN 1+
Speaker - to PIN 1-
Bridged
A
AA
A
AA
AA
+
+
+
+
+
VF Series Power Amplifiers
MODELS VF150, VF300, VF600, VF800
R

Active clip limiting
At the amplifier's full power limit, or clipping point, ACL will be activated. This is indicated by illumination
of the Limiter LED. The channel gain is automatically reduced, protecting the loudspeakers from potential
damage from the high power, continuous square waves that would otherwise be produced. ACL may be
activated by uncontrolled feedback, oscillations, improper equipment gain settings, or an equipment
malfunction upstream from the amplifier. Only steady or excessive clipping (not normal program transients)
will trigger ACL. The circuit is virtually transparent in operation and full signal bandwidth is maintained.
IGM Impedance Sensing
IGM (Instantaneous Gain Modulation) is an innovative circuit that allows the amplifier to operate safely
into difficult loads. When the amplifier sees a load that overstresses the output stage, the IGM circuit
adjusts the channel gain to a safe level similar to ACL, the IGM circuit is inaudible in normal use. In
addition, if extreme and sustained low impedance is encountered, the amplifier's output relay will open.
Auto Ramp Protection
Auto Ramp operates every time the amplifier is turned on or is reactivated after a protect condition is
corrected. This exclusive feature gradually increases gain to the attenuator setting avoiding
unnecessary stress on the loudspeakers.
Thermal Protection
Abnormally high heat sink temperatures will engage the Protect circuit for the overheating channel only.
(An output relay disconnects the loudspeakers until nominal temperature range is restored.) During this
time, the Protect LED will light. If the power transformer gets too hot, its thermal sensing circuit will disconnect
both channel outputs. During this time, the Power LED will extinguish, the Protect and Limiter LEDs
will stay lit,
and the cooling fan will continue running at low speed. Normal operation resumes once the transformer
cools to a safe level.
Short Circuit
If an output is shorted (i.e., defective speakers or crossed speaker wires) the IGM and thermal circuits will
automatically protect the amplifier. The IGM circuit senses the short circuit as an extremely stressful load
condition and attenuates the signal, protecting the channel's output transistors from over-current stress. If
the short circuit remains, the load will be disconnected by the thermal protection circuitry (output relay opens).
DC Voltage Protection
If an amplifier channel detects DC voltage at its output terminals, the output relay will immediately open to
prevent loudspeaker damage. The Protect LEDs will light.
Subsonic Frequencies
Built-in high pass filtering provides subsonic frequency protection for each channel. In addition, a relay will
open if excessive subsonic energy appears at the output.
Protection Features
Page10
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VF Series Power Amplifiers
MODELS VF150, VF300, VF600, VF800
R
S E R I E S
VF
R

User Precautions
Speaker Protection
All loudspeakers have electrical, thermal, and physical limits which must be observed to prevent damage
or failure. Cone or compression drivers can be damaged (sometimes to the point of failure) from excessive
power, low frequencies applied to high frequency drivers, severely clipped waveforms, and DC voltage.
All VF Series amplifiers automatically protect speakers from DC voltages and subsonic signals.
Mid- and high-frequency transducers-compression driver in particular are highly susceptible to damage
from overpowering, clipped waveforms, or frequencies below their rated passband. When using an
electronic crossover, make absolutely certain that the low and mid bands are connected to the correct
amplifiers and drivers and not accidentally connected to those for a higher or lower frequency band.
The amp lifier's clipping point is its ma ximu m peak output power. At ma ximu m peak output power, VF
Series amplifiers will deliver more power than many speakers can safely handle. Be sure the peak power
capability of the amplifier is not excessive for your speaker system. To ensure that the speakers never
receive excessive power, and to prevent amplifier clipping, use a properly adjusted external limiter (or
a compressor with a ratio of 10:1 or higher) to control power output. Use one compressor/limiter for each
frequency band in systems with active electronic Crossovers.
The ACL clip limiting circuit will automatically limit the duration of squared-off, continuous waveforms
applied to the speakers. The amplifier will, however, allow normal musical transient bursts to pass. Of
course, when the amplifier does clip, it is operating at its maximum output power. Note that some speaker
systems are packaged with proprietary "processors" that have power limiting circuits and therefore should
not require additional limiting.
Do not drive any low-frequency speaker enclosure with frequencies lower than its own tuned frequency;
the reduced acoustical damping could cause a ported speaker to "bottom out" even at moderate power.
Consult the speaker system specifications to determine its frequency limits, and employ a roll-off filter if
necessar y.
Page 11
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VF Series Power Amplifiers
MODELS VF150, VF300, VF600, VF800
R
S E R I E S
R
VF

Maintenance
A VF S eries a mplifier requires n o routine maintenance other than o ccasional cleaning or replacement
of the fan intake filters on the rear of the amplifier. (This operation does not require any tools). Filters must
be kept clear and clean to ensure proper ventilation through the unit. If the amplifier is used in an
ext remely
dusty or smoky environment, the filter should be cleaned or changed frequently and the unit should be
periodically "blown free" (using compressed air) of any foreign matter that may penetrated through
the
filter.
Users will not need to make any internal adjustments to the amplifier during its lifetime. There are no user
serviceable parts or adjustments that require opening the power amplifier. Cover removal exposes the
risk of shock, so refer all servicing to qualified service technicians authorized by .
User Responsibility
Your VF Series amplifier is ver y powerful and can be potentially dangerous to loudspeakers and operat-
ors alike. It is your responsibility to read the section titled "Important Precautions" and make sure that the
amplifier is installed, wired, and operated properly as instructed in this manual. Many loudspeakers can
be easily damaged or destroyed by overpowering, especially with the high power available from a bridged
amplifier. Read the section on Speaker Protection and always be aware of the
speaker's continuous
and peak power capabilities.
Service and Repair
is not responsible for damage to loudspeakers.
In the unlikely event that your amplifier develops a problem, it must be returned to an authorized
distributor, service centre or shipped directly to our factor y. To obtain service, contact your nearest
service centre,distributor or dealer.Because of the complexity of the design and the risk of
electrical shock, all repairs should be attempted only by qualified technical personnel. If the unit
needs to be shipped back to the factory, it must be sent in its original carton. If improperly packed,
your amplifier may be damaged.
Page 12
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R
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VF Series Power Amplifiers
MODELS VF150, VF300, VF600, VF800
R
S E R I E S
VF
R
R
For those with Internet access, please visit the website at: Http//www.nicemic.co.kr

S E R I E S
Appendices
VF

Appendix A - Amplifier Specifications
S E R I E S
For full power at 4 Ohms.* 3Year guarantee.
reserves the right to make changes or improvements in manufacturing or design which may affect specification.
Appendix A
VF
R
R
VF Series Power Amplifiers
MODELS VF150, VF300, VF600, VF800
R
1kHz, 0.1% THD+N
20Hz-20kHz, 0.1% THD+N
Max RMS Output Voltage (each channel)
Max Peak Output Voltage
TourClass Protection
Input CMRR (1kHz)
Standard Input Sensitivity (rated power at 8 )
Input Impedance (balanced/unbalanced)
Hum and Noise ("A" weighted, -80 dBW)
Crosstalk ("A" weighted, full power at 4 )
Class
Input Connectors (per channel)
Output Connectors (per channel)
Power Supply (factor y configured)
Idle Current Draw (220V)
1/8 Power Curr. Draw (typical music cond., 220V/4 )
1/3 Power Curr. Draw (cont. music cond., 220V/4 )
Max Curr. Draw (continuous music cond., 220V/4 )
Cooling
Controls
LED Indicators (per channel)
Construction
Dimensions (Height x Width x Depth to rear rack ears)
Gross Weight
Net Weight
Warranty
4 Stereo Power
8 Stereo Power
8 Bridged Mono Power
8 Stereo Power
4 Stereo Power
8 Bridged Mono Power
Frequency Response (+0 / -0.3dB, 1W/8 )
Power Bandwidth (rated power at 4 , 1%THD+N)
THD+N (rated power, 4 /1kHz)
SMPTE IMD (rated power, 8 , 50 Hz & 7kHz)
Damping Factor (10-400Hz at 8 )
TM
LX ,Th erm al ACL, IGM, AutoRamp, sh ort circ uit, DC voltage, tu rn -on/o ff tr ansi ent, curr ent inru sh , su b/ultraso nic input
Female Neutr ik XLR (p in 2+, confi gura ble fo r pin 3+), TRS (tip+)
2-way binding posts & Speakon connecto rs Neutr ik
Two re ar panel vari able speed
DC fans, filte rs detatc hable
without to ols
Lim it, Signal, Temp/DC, Acti ve
Ste el chass is, 16 gauge. Double thickn ess in rack ear are as.
2 X100W
2 X150W
400W
2 X95W
2 X142W
285W
28V
40V
0.1A
1.3A
2.4A
3.7A
12.5kgs
9.5 kgs
VF150
20Hz-20kHz, (+ /-1dB)
20Hz-20kHz, -0.84dB/+0dB
2 X450W
2 X700W
1500W
2 X430W
2 X670W
1330W
63V
89V
0.2A
5.25A
11.5A
15.0A
88 x 482 x 397mm
23kgs
19 kgs
VF800VF300
2 X200W
2 X330W
500W
2 X210W
2 X310W
630W
36V
51V
0.2A
2.8A
5.0A
8A
17kgs
13 kgs
2 X350W
2 X500W
1100W
2 X310W
2 X480W
960W
51V
72V
0.2A
4.3A
8.0A
10.5A
VF600
Front panel: 2 atte nuators, power switch; Rear panel: signal ground lift & mode switc hes; limite r switch ,fi lte r switch
<0.1%
<0.1%
≥300
> 60 dB
0.775V/1V/1.44V
100dB
>60dB
AB
44 x 482 x 336mm
3 years*
20k /10k
19 kgs
15 kgs
Two-speed fans
220V/60Hz
1V
Crossover
120Hz-20kHz-6dB
20Hz-120Hz-6dB
Low pass
High pass

Appendix B - VF Block Diagram
+ NON-INVERTED
- INVERTED
+ NON-INVERTED
- INVERTED
B
B
+
-
ATTENUATOR
AMP FRONT END
OUTPUT STAGE
OUTPUT RELAY
ATTENUATOR
AMP FRONT END
OUTPUT STAGE
OUTPUT RELAY
CHANNEL A
CHANNEL B
PREAMP
PREAMP
BRIDGED
PARALLEL
STEREO
SWITCH
R
T
R
T
2/3
2/3
1
2
3
1
2
3
JUMPER
(REAR PANEL SWITCH
ON CA18)
PIN 2/3+
JUMPER
(REAR PANEL SWITCH
ON CA18)
PIN 2/3+
A
+
A
-
FILTER
SELECTOR
FILTER
SELECTOR
Appendix B
S E R I E S
VF
R
VF Series Power Amplifiers
MODELS VF150, VF300, VF600, VF800
R

Appendix C - Wire Gauge Chart (Metric)
Wire Gauge (mm2) Power Loss Power Loss Power Loss
0.3 (8 ohm load) (4 ohm load) (2 ohm load)
0.5 2.9% 5.6% 10.8%
0.75 1.74 3.4 6.7
1.5 1.16 2.3 4.5
2.5 0.58 1.16 2.3
0.35
40.70 1.39
0.5 0.22 0.44 0.87
0.75 4.3% 8.2% 15.5%
1.5 2.9 5.6 10.8
2.5 1.45 2.9 5.6
40.87 1.74 3.4
60.55 1.09 2.2
0.5 0.37 0.73 1.45
0.75 8.24% 15.5% 28%
1.5 5.6 10.8 19.9
2.5 2.9 5.6 10.8
4 1.74 2.9 6.7
61.09 1.74 4.3
0.75 0.73 1.09 2.9
1.5 15.5% 0.73% 45%
2.5 8.2 15.5 28
45.1 9.8 18.2
63.2 6.3 12.0
10 2.2 4.3 8.2
1.31 2.6 5.1
Strand ed Cable Lgt h( m)
2
5
10
30
Appendix C
S E R I E S
S E R I E S
VF
R
VF Series Power Amplifiers
MODELS VF150, VF300, VF600, VF800
R

S E R I E S
VF
R
Stranded Cable Lgth(ft )
5
10
40
80
Wire Gaug e (AWG)
Power Loss Power Loss Power Loss
18 (8 ohm load) (4 ohm load) (2 ohm load)
16 0.81% 1.61% 3.2%
14 0.51 1.02 2.0
12 0.32 0.64 1.2 8
10 0.20 0.40 0.80
18 0.128 0.25 0.51
16 1.61% 3.2% 6.2%
14 1.02 2.0 4.0
12 0.64 1.28 2.5
10 0.40 0.80 1.60
18 0.25 0.51 1.0 1
16 6.2% 11.9% 22%
14 4.0 7.7 14.6
12 2.5 5.0 9.6
10 1.60 3.2 6.2
81.01 2.0 4.0
18 0.60 1.20 2.4
16 11.9 % 22% 37%
14 7.7 14.6 26
12 5.0 9.6 17.8
10 3.2 6.2 11.8
82.0 4.0 7.7
1.20 2.4 4.7
Appendix C
VF Series Power Amplifiers
MODELS VF150, VF300, VF600, VF800
R

Choice of touring professionals.
R
PROFESSIONAL POWER AMPLIFIER
NICE Technology for Sound Co,.Ltd.
SangGae-2Dong,1309-1 HANIL UNI B/D
2F,Nowon-Gu,Seoul,Korea
TEL:[phone]