Furman VU-40 User manual

FURMAN
SOUND,
INC.
30
RICHSTREET
GREENBRAE,CALIFORNIA94904
PHONE:
(41s)
927-1225
FAX:
(415)
927-4548
----J- S f S
-- JA7-- - f-
hf fH=---
FU'T'ffS'J
lntroduction
Congratulations
on yourpurchase of a Furman
SoundModel
VU-40StereoSystemMonitor. The VU-40 is a convenientrack-
mountdual
channellevelmonitor
for useinsoundreinforcement,
concertsound,recordingstudiomonitoring,or in any application
whereaquick visualcheckofsystem
performance
isdesirable.
VU-40Features
O Twoindependentmetering channels
O On/offtransient
muting
function
protects
speakers
O FamiliarVUmeterscales
O Greenl/ellodRed LEDcolorcoding
O Peak orAverageresponse switch
O LineLevel/Power Outswitchforeachchannel
O LineLevelmaybesetto-10,
0,or+4dBu
O Sixteen
Power
Outchoicesfrom20to 1260
Watts
O Groundlift,on/offswitches
Operation
FrontPanel
TheVU-40
iscomprised
oftwo20LEDbar-graphmeters,
cali-
brated
in dB likestandardVU meters. They may be set with the
pushbutton
switchontheleft
sideofthefront
panel
to readeither
Peak(button in)or Average(button
out) response. The two me-
ter scalesabovethe LED's
are usedfor Average,while
the two
scales
below
arefor Peak. Because
audiosignalsare AC (alter-
natingcurrent),theiractualvoltagelevel
variesfrom millisecond
to millisecond.
"Average"
refers
to the averagemagnitudeduring
a timespanof about1/4 second.To approximate
the action
of a
traditional
electromechanicalVU meter,choose
the Average
set-
ting. Average
also
gives
a goodindication
ofthe perceived loud-
nessofthesignal.The Peak
settingindicates
thehighest
point
of
the waveform,regardless of the average. Therefore,
the Peak
position
will
alwaysresultinhigherreadings,
butitwill
give
atruer
indication
ofhow closethesignalis
toclipping.
Rear Panel
The Input
Selectswitches
on the rear-panel
selecteitherLine
(line
level)orAmplifier
(power
output),
allowing
youto monitor
ei-
therthe inputs or outputs,respectively,
of a poweramp. Since
eachchannelmaybeswitchedindependently,
another
possibility
isto useoneVU-40
channelforinput
andtheotherforoutput.Of
4-9532
course,theLinesetting
maybe usedto monitor anylinelevel sig-
nal,even
if nopower ampis involved. ForLine,the"zero"
meter
positions
maybeset
toeither
-10,
0,or
+4dBuwiththeLineInput
slideswitch. Thisswitch
controlsboththe leftandrightchannels
(assuming
botharesetto the Line
position
with
their
Input
Select
switches).
Forline
levelmetering,
refer
tothe white scalesonthe
front
panel,
whicharecalibratedindecibels.
Thechoiceof -10,
0,
or+4 dependsonthenominal
linelevel
oftheother equipment
in
your
system,especially
the mixer andtaperecorder.lf in doubt,
consultthemanuals
forthatequipment.
When eitheror both of the InputSelectswitches
are set to
Amplifier,theVU-40
is readyto monitorthe output(s)of a power
amp. The blue scales,calibrated
in percent
of full power,are
used.
Thereare16power
outputchoices
from20to 630 wattsfor
8 ohm loads, or from40 to '1260
wattstor 4 ohm loads. Check
themaximum
power
output
foryouramplifier
andthe ratedimpe-
dance
ofyour speakers
todetermine
whichrange
to use. Theex-
act wattagecorresponding
to 100 percent
is determinedby the
settingsofthefour
AmplifierPowerswitches,accordingtothefol-
lowingtable. Theswitches
areshownas seen
atthe rear
panel,
fromleft
(closest
to PowerAmpbinding
posts)
to right.
In adjustingsystem levels,the VU-40'smetersserve as a
guide
to avoidoverdriving
thepower amplifier,
which
canresultin
Amplifier
Power
Switches
When
switchesare setas follows: The 100o/oreadingin wattsi,
Left
down down down
up down down
down up down
up up down
down down up
up down up
down up up
up up up
down down down
up down down
down up down
up up down
down down up
up down up
down up up
up up up
Right Sohms 4ohms
down 20 40
down 25 50
down 32 64
down 40 80
down 50 100
down 63 126
down 80 160
down 100 200
up 125 250
up 160 32O
up 20O 400
up 250 500
up 320 640
up 400 800
up 500 1000
up 630 1260
960020-609

clipping
distortion.
Theamplifie/s
output
should
only
rarely
beal-
lowedto exceed 1000/"
of its ratedpower.The meter LED's are
cofor coded red above 100% so you can see overloads at a
glance.
Whenonlygreen
lights
show,the amp is operating
in a
safe
range.
Inbetween,
therearethree
yellow
lights
warningthat
the
signal
levelis
close
tooverdriving.
Transient
Muting
A special
VU-40featureis turn-on/turn-off
transient
muting.
To useit,line
levelfeedsto thepower
ampare routed
first
tothe
VU-40,thenback
outto the power
amp. WhenAC power
is ap-
plied
or removed,thepower
ampfeedwillbe mutedfor onesec-
ond,
eliminating
loudthumps
withtheir
potential
forspeaker
dam-
age. With a VU-40channelassignedin this fashionto each
power
amp in a system,the entiresystemmay be switchedon
andoffwithone masterswitch,providing
an extradegreeof pro-
tection
for
systems
operated
byinexperienced
personnel.
lnstallation
The VU-40's
connectors
includeboth a 1/4 inch phone
jack
and
anRCA
jack
forLine
Levelinput
andoutput
foreach
channel.
lfthe VU-40
isto be usedonly
for linelevelmonitoring,only
the
input
jacks
needbe used. However,since
thismightnecessitate
splitting
the
signal
tobemonitoredwitha Y-cordorsimilardevice,
youmay
findit more
convenient
to usethe VU-40'soutput
jacks
aswell,
routingthesignal
inandthenback
out. Thismethod also
provides
the benefit
of the transient
mutingfeature. lf desired,
boththephone
andtheRCA
output
jacks
canbe usedsimultane-
ously. Thiscanbe useful
forsignalsplitting,
if,for instance,
you
wantto routethesignal
to morethanonepower
amp. However,
onlyoneof thetwo input
jackson eachchannel
shouldbe used
as an input(thetwo jacks are connectedtogether,so the other
jack
canbeused
asanoutput,
butitwillnothavetheonesecond
mute). For best results,all cables carryingline level signals
should
beshielded.
For
Powermonitoring,a pair
of banana
jacVbinding
post
ter-
minals
areprovided
for eachchannel.
The bananaterminalsare
balanced,
floating,and isolated,so thatthe VU-40
can be safely
connected
to any poweramp outputwithoutregardfor polarity.
These cables do not need to be shielded. Warning: To avoid
damageto the VU-40,do not connect a power amp output to any
phone or RCAjack. Power amp outputs or speakers must con-
nectonlyto thebindingposfs labeled "PowerAmplifier."
It is possible
to usethe VU-40for Powermonitoringand still
usethetransient
mutingfeature. Simply
connectthe power amp
outputstothebanana
jacks,
setthe lnput Select
switchesto Am-
plifier,
and routethe line levelsignalat the point to be muted
(generally
just beforethe poweramp or crossover,
if used)into
andout
ofthephone orRCA
jacks.
The VU-40is intended
for mountingin standard
19"equip-
ment
racks.A logicalspotto installitwouldbejust
abovetheamp
whoseoutputit is monitoring. Standard
rackscome equipped
withmounting
railswithholes tapped
for 10-32machinescrews.
Be sure to use only 10-32 screws (in pailicular,avoid 10-24
screws,
which
willfit ifforcedbutwillstripthe threads).
To avoid
marringthepanel
when
tightening
thescrews,usenylonwashers
under
thescrew
heads.
Ground Lift Switch
In manyinstallations,hum-causing
groundloopsare formed
bythecommonconnection
of various
pieces
of equipmentto the
power
line
ground,
andby contactbetweenchassis,as in a rack
withmetal
rails. Slidingthe ground
liftswitch up completely
iso-
latesall signalgrounds
from the chassis,breaking
any ground
loops. Thechassis
always
remains
connected
to thegroundpin
ontheAC cord
forsafety andto provide shielding
againstRFin-
terference.
Balanced Option
lf the balanced
option has been installed
(ModelVU-408)'
XLR connectors
willbe present
on eachchannel
for bothinputs
and outputs. Balanced
linesoffer
the benefits
of cancellation
of
hum,noise,
and RF interference
whichmay be picked
up in the
interconnecting
cables. Forbalanced
connections,
shielded
twist-
ed pair
cable
mustbe used. lf desired,
the XLR (balanced)
and
phone(unbalanced)outputs
maybe usedsimultaneously.
How-
ever,only
oneofthe
twoinputs
should
beused.
Limited
Warranty
TheFurman
VU-40
iswarranted
against
failures
dueto defec-
tive
parts
orfaulty
workmanship
fora period
ofone
year
afterde-
liveryto the original
owner.
Duringthisperiod,
Furman
willmake
anynecessary
repairs
withoutcharge
for parts
or labor-Shipping
charges
to the factory
or repairstation
must be prepaid
by the
owner;
returnshipping
charges
(viaUPSGround) willbe paid
by
Furman.
This warranty
applies
only to the original
ownerand is not
transferable.
Also,
itdoes'not
apply
to repairs
done
otherthanby
theFurmanfactory
orAuthorized
RepairStations.
Thiswarranty
shallbecancelable
byFurmanatitssolediscre-
tion
iftheVU-40
unit
hasbeen
subjected
to physical
abuse
orhas
been modifiedin any way without written authorization
from
Furman.
Furman's
liability
under
thiswarranty
is limited
to repair
orreplacement
ofthedefective
unit.
Furman
willnotbe responsible
for incidental
orconsequential
damages
resulting
fromthe use or misuseof itsproducts.
Some
statesdo not allowthe exclusion
of incidental
or consequential
damages,
so the above limitations
may not applyto you. This
warranty
givesyou specific legalrights,and you may alsohave
other
rights
which
varyfromstate
tostate.
Warranty
claims
should
beaccompanied
byacopy
oftheorig-
inalpurchase
invoice
showing
the purchase
date (if a Warranty
Registration
Cardwas mailed
in at the time of purchase,
thisis
notnecessary).
Before
returninganyequipment
for repair,
please
readtheimportant
information
onservice
below.
Service
Before
returning
anyequipment
for repair,
please
besurethat
it is adequately
packed
and cushioned
against
damage
in ship-
ment,and
thatitisinsured.
We suggest
that
yousavetheoriginal
packaging
and use it to ship the productfor servicing.
Also,
please
enclose
a note
givingyourname, address,
phone
number
and
a description
oftheproblem.
NOTE:All equipment
being
returned
for repairmust
havea
Return Authorization
(R/A) Number.To get an R/A Number,
pfease
call
the FurmanService
Department,
(415)
927-1225,
be-
tween
8 amand5 pm U.S.Pacific
Time.Pleasedisplay
yourR/A
Number
prominently
on
the
frontofall
packages.
VU-40SPECIFICATIONS
LINE
IwOUT Input
lmpedance: Greaterthan
200K
ohms.
Sensitivity
for0 VU: -10
dBu
(.245
Vrms)or0dBu
(.775
Vrms)or
+4dBu
(1.23
Vrms)
Turn-onDelay: APProximatelY
1
Sec
Max.
ThroughLevel: +22dBu
(10
Vrms)
Connectors: VU-40:1/4"
phone
and
RCA
VU-40B:
Phone,RCA,and
XLR
POWER
AMP Input
lmpedance: Greater
than
200Kohms.
INPUTS Sensitivity
for0 VU: 16
switch
selectable
calibrated
sensitivities
foreither 20to630
Wafts
at8 ohms,
or
40
to 1260W at
4ohms
Connectors: Bananabinding
Post.
METERS Accuracy: +0.5dB (factory
setinternaltrim
pot).

clipping
distortion.
Theamplifie/s
output
should
only
rarely
beal-
lowedto exceed 1000/"
of its ratedpower.The meter LED's are
cofor coded red above 100% so you can see overloads at a
glance.
Whenonlygreen
lights
show,the amp is operating
in a
safe
range.
Inbetween,
therearethree
yellow
lights
warningthat
the
signal
levelis
close
tooverdriving.
Transient
Muting
A special
VU-40featureis turn-on/turn-off
transient
muting.
To useit,line
levelfeedsto thepower
ampare routed
first
tothe
VU-40,thenback
outto the power
amp. WhenAC power
is ap-
plied
or removed,thepower
ampfeedwillbe mutedfor onesec-
ond,
eliminating
loudthumps
withtheir
potential
forspeaker
dam-
age. With a VU-40 channelassignedin this fashionto each
power
amp in a system,the entiresystemmay be switchedon
andoffwithone masterswitch,providing
an extradegreeof pro-
tection
for
systems
operated
byinexperienced
personnel.
lnstallation
The VU-40's
connectors
includeboth a 1/4 inch phone
jack
and
anRCA
jack
forLine
Levelinput
andoutput
foreach
channel.
lfthe VU-40
isto be usedonly
for linelevelmonitoring,only
the
input
jacks
needbe used. However,since
thismightnecessitate
splitting
the
signal
tobemonitoredwitha Y-cordorsimilardevice,
youmay
findit more
convenient
to usethe VU-40'soutput
jacks
aswell,
routingthesignal
inandthenback
out. Thismethod also
provides
the benefit
of the transient
mutingfeature. lf desired,
boththephone
andthe RCA
output
jacks
canbe usedsimultane-
ously. Thiscanbe useful
forsignalsplitting,
if,for instance,
you
wantto routethesignal
to morethanonepower
amp. However,
onlyoneof thetwo input
jackson eachchannel
shouldbe used
as an input(thetwo jacks are connectedtogether,so the other
jack
canbeused
asanoutput,
butitwillnothavetheonesecond
mute). For best results,all cables carryingline level signals
should
beshielded.
For
Powermonitoring,a pair
of banana
jacVbinding
post
ter-
minals
areprovided
for eachchannel.
The bananaterminalsare
balanced,
floating,and isolated,so thatthe VU-40
can be safely
connected
to any poweramp outputwithoutregardfor polarity.
These cables do not need to be shielded. Warning: To avoid
damageto the VU-40,do not connect a power amp output to any
phone or RCAjack. Power amp outputs or speakers must con-
nectonlyto thebindingposfs labeled "PowerAmplifier."
It is possible
to usethe VU-40for Powermonitoringand still
usethetransient
mutingfeature. Simply
connectthe power amp
outputstothebanana
jacks,
setthe lnput Select
switchesto Am-
plifier,
and routethe line levelsignalat the point to be muted
(generally
just beforethe poweramp or crossover,
if used)into
andout
ofthephone orRCA
jacks.
The VU-40is intended
for mountingin standard
19"equip-
ment
racks.A logicalspotto installitwouldbejust
abovetheamp
whoseoutputit is monitoring. Standard
rackscome equipped
withmounting
railswithholes tapped
for 10-32machinescrews.
Be sure to use only 10-32screws (in pailicular,avoid 10-24
screws,
which
willfit if forcedbutwillstripthe threads).
To avoid
marringthepanel
when
tightening
thescrews,usenylonwashers
under
thescrew
heads.
Ground Lift Switch
In manyinstallations,hum-causing
groundloopsare formed
bythecommonconnection
of various
pieces
of equipmentto the
power
line
ground,
andby contactbetweenchassis,as in a rack
withmetal
rails. Slidingthe ground
liftswitch up completely
iso-
latesall signalgrounds
from the chassis,breaking
any ground
loops. Thechassis
always
remains
connected
to thegroundpin
ontheAC cord
forsafety andto provide shielding
againstRFin-
terference.
Balanced Option
lf the balanced
option has been installed
(ModelVU-408)'
XLR connectors
willbe present
on eachchannel
for bothinputs
and outputs. Balanced
linesoffer
the benefits
of cancellation
of
hum,noise,
and RF interference
whichmay be picked
up in the
interconnecting
cables. Forbalanced
connections,
shielded
twist-
ed pair
cable
mustbe used. lf desired,
the XLR (balanced)
and
phone(unbalanced)outputs
maybe usedsimultaneously.
How-
ever,only
oneofthe
twoinputs
should
beused.
Limited
Warranty
TheFurman
VU-40
iswarranted
against
failures
dueto defec-
tive
parts
orfaulty
workmanship
fora period
ofone
year
afterde-
liveryto the original
owner.
Duringthisperiod,
Furman
willmake
anynecessary
repairs
withoutcharge
for parts
or labor-Shipping
charges
to the factory
or repairstation
must be prepaid
by the
owner;
returnshipping
charges
(viaUPSGround) willbe paid
by
Furman.
This warranty
applies
only to the original
ownerand is not
transferable.
Also,
itdoes'not
apply
to repairs
done
otherthanby
theFurmanfactory
orAuthorized
RepairStations.
Thiswarranty
shallbecancelable
byFurmanatitssolediscre-
tion
iftheVU-40
unit
hasbeen
subjected
to physical
abuse
orhas
been modifiedin any way without written authorization
from
Furman.
Furman's
liability
under
thiswarranty
is limited
to repair
orreplacement
ofthedefective
unit.
Furman
willnotbe responsible
for incidental
orconsequential
damages
resulting
fromthe use or misuseof itsproducts.
Some
statesdo not allowthe exclusion
of incidental
or consequential
damages,
so the above limitations
may not applyto you. This
warranty
givesyou specific legalrights,and you may alsohave
other
rights
which
varyfromstate
tostate.
Warranty
claims
should
beaccompanied
byacopy
oftheorig-
inalpurchase
invoice
showing
the purchase
date (if a Warranty
Registration
Cardwas mailed
in at the time of purchase,
thisis
notnecessary).
Before
returninganyequipment
for repair,
please
readtheimportant
information
onservice
below.
Service
Before
returning
anyequipment
for repair,
please
besurethat
it is adequately
packed
and cushioned
against
damage
in ship-
ment,and
thatitisinsured.
We suggest
that
yousavetheoriginal
packaging
and use it to ship the productfor servicing.
Also,
please
enclose
a note
givingyourname, address,
phone
number
and
a description
oftheproblem.
NOTE:All equipment
being
returned
for repairmust
havea
Return Authorization
(R/A) Number.To get an R/A Number,
pfease
call
the FurmanService
Department,
(415)
927-1225,
be-
tween
8 amand5 pm U.S.Pacific
Time.Pleasedisplay
yourR/A
Number
prominently
on
the
frontofall
packages.
VU-40SPECIFICATIONS
LINE
IwOUT Input
lmpedance: Greaterthan
200K
ohms.
Sensitivity
for0 VU: -10
dBu
(.245
Vrms)or0dBu
(.775
Vrms)or
+4dBu
(1.23
Vrms)
Turn-onDelay: APProximatelY
1
Sec
Max.
ThroughLevel: +22dBu
(10
Vrms)
Connectors: VU-40:1/4"
phone
and
RCA
VU-40B:
Phone,RCA,and
XLR
POWER
AMP Input
lmpedance: Greater
than
200Kohms.
INPUTS Sensitivity
for0 VU: 16
switch
selectable
calibrated
sensitivities
foreither 20to630
Wafts
at8 ohms,
or
40
to 1260W at
4ohms
Connectors: Bananabinding
Post.
METERS Accuracy: +0.5dB (factory
setinternaltrim
pot).