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).
