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1
Cele
brat
ing
the
Crow
n M
acro
-Tec
h Se
ries Y
our
Mac
ro-T
ech®
Sig
natu
re S
erie
s am
plifi
er
is th
e
culm
inat
ion
of a
long
her
itag
e of
Cro
wn®
pro
duc
ts
and
des
ign
idea
s th
at b
egan
in th
e ea
rly 1
970s
.
In th
ese
pag
es y
ou c
an e
xplo
re h
ow th
e M
acro
-Tec
h S
erie
s
cam
e to
be,
und
erst
and
its
adva
nced
feat
ures
, and
enj
oy
stor
ies
and
sal
es li
tera
ture
from
its
colo
rful
pas
t.
2
Som
etim
es a
pro
duc
t fi ts
an
app
licat
ion
so w
ell,
it
is d
eem
ed a
cla
ssic
. The
term
is s
ynon
ymou
s w
ith
the
Cro
wn®
Mac
ro-T
ech
Ser
ies
of p
ower
am
plifi
ers
.
That
pro
duc
t lin
e, a
nd it
s p
red
eces
sor
Mic
ro-T
ech®
, sp
arke
d
inno
vativ
e te
chno
log
ies
that
pro
vid
ed lo
wer
dis
tort
ion,
less
ther
mal
str
ess,
hig
her
outp
ut p
ower
, gre
ater
rel
iab
ility
, mor
e
pow
er d
ensi
ty a
nd s
uper
ior
aud
io q
ualit
y.
No
com
pro
mis
es, n
o g
imm
icks
. Jus
t bril
liant
eng
inee
ring
bac
ked
by
sup
erio
r m
anuf
actu
ring
, sup
por
t and
an
unsu
rpas
sed
com
mitm
ent t
o q
ualit
y.
Like
all
Cro
wn
amp
s, th
e d
efi n
ing
cha
ract
eris
tic o
f the
Mac
ro-
Tech
Ser
ies
is s
onic
acc
urac
y. A
tig
ht, r
ock-
solid
low
end
, with
smoo
th, d
etai
led
hig
hs a
nd a
wel
l-defi
ned
mid
rang
e. In
sho
rt,
Cro
wn
Mac
ro-T
ech
Serie
s
Enjoy
!
the
mos
t acc
urat
e re
pro
duc
tion
of a
n au
dio
sig
nal y
ou’v
e ev
er
hear
d. A
nd b
ecau
se w
e p
ut th
e q
ualit
y of
sou
nd a
bov
e al
l els
e,
Cro
wn
amp
lifi e
rs a
re th
e m
ost c
ovet
ed in
the
bus
ines
s.
Whe
n it
com
es to
man
ufac
turin
g a
mp
s, o
ur w
ork
is b
ased
on
one
sim
ple
fact
: the
re a
re n
o sh
ortc
uts
to q
ualit
y. A
nd o
ur M
acro
-
Tech
s ha
ve p
rove
n th
is ti
me
and
tim
e ag
ain
in s
ome
of th
e m
ost
dem
and
ing
ap
plic
atio
ns in
the
wor
ld.
For t
his
spec
ial,
limite
d M
acro
-Tec
h re
leas
e, w
e w
ante
d to
brin
g
you
mor
e th
an ju
st th
e ty
pic
al o
per
atio
n m
anua
l. Th
is b
roch
ure
goe
s m
uch
furt
her,
del
ving
into
the
Mac
ro-T
ech’
s d
evel
opm
ent,
des
ign
phi
loso
phy
, and
ad
vanc
ed te
chni
cal f
eatu
res.
We’
ve a
lso
incl
uded
som
e b
roch
ures
from
the
pas
t, a
bio
of C
row
n’s
chie
f R&
D
eng
inee
r Ger
ald
Sta
nley
, cus
tom
er s
tatis
tics,
ane
cdot
es a
nd m
ore.
Sin
ce 1
984,
Cro
wn
has
sh
ipp
ed
app
roxi
mat
ely
272,
625
MT
an
d M
A
amp
lifi e
rs t
o d
ate.
Th
at’s
ap
pro
xim
atel
y
54 m
illio
n w
atts
into
4 o
hm
s o
r 65
mill
ion
wat
ts in
to 2
oh
ms!
3C
row
n M
acro
-Tec
h am
plifi
ers
wer
e us
ed a
t the
64,
640-
seat
San
gam
Sta
dium
in S
eoul
, Sou
th K
orea
, dur
ing
the
2002
Wor
ld C
up.
4
A Sa
mpl
ing
of C
row
n M
acro
-Tec
h U
sers
TH
EM
E P
AR
KU
nive
rsal
Stu
dio
s
Eve
rland
(K
orea
)
Six
Fla
gs
of A
mer
ica
FIX
ED
INS
TALL
Clu
b C
apita
le
Syd
ney
2000
Oly
mp
ics
Cry
stal
Cat
hed
ral
Offi
cial
All
Sta
r C
afe
Har
d R
ock
Live
Exp
erie
nce
Mus
ic P
roje
ct
Sp
irit,
Rox
y
Dee
p n
ight
clu
bs
TO
UR
Nei
l Dia
mon
d to
ur
Pro
Sho
w, S
PL
Sou
nd, X
FL
Seo
ul W
ord
Cup
200
2
Aud
io A
naly
sts
Mor
gan
Sou
nd
Cla
ir B
roth
ers
Dis
turb
ed (
ban
d)
Art
Gar
funk
el T
our
Mar
ylan
d S
ound
Gem
ini S
ound
On
Sta
ge
Aud
io
Ent
erp
rise
Live
STA
DIU
M /
AR
EN
AA
mer
ican
Airl
ines
Are
na
Am
eric
an A
irlin
es C
ente
r
Ral
ph
Eng
elst
ad A
rena
Key
Are
na
Xce
l Ene
rgy
Are
na
Con
seco
Fie
ld H
ouse
Coo
rs F
ield
Volk
swag
en S
tad
ium
Hon
g K
ong
Sta
diu
m
Rac
ks o
f Cro
wn
Mac
ro-T
ech
ampl
ifi er
s po
wer
this
200
1 ex
trav
agan
za s
tage
d in
Sal
t Lak
e C
ity’s
Sal
t Pal
ace
for
the
Ann
ual
Gal
a he
ld b
y U
tah
Gov
erno
r M
ike
Leav
itt. R
ocky
Mou
ntai
n A
udio
Vis
ual c
hose
Cro
wn
Mac
ro-T
ech
alon
g w
ith J
BL
Ver
tec
spea
kers
to p
rovi
de c
once
rt-q
ualit
y so
und
for
the
even
t. (F
ind
out m
ore
at h
ttp://
ww
w.jb
lpro
.com
/pre
ssro
om/r
mav
_uta
h.ht
m.)
5C
row
n M
acro
-Tec
h am
plifi
ers
pow
er th
e pr
emiu
m s
ound
sys
tem
em
ploy
ing
JBL
PD
Ser
ies
spea
kers
in th
e 40
0,00
0 sq
. ft.
Ral
ph E
ngel
stad
Are
na in
Gra
nd F
orks
, Nor
th D
akot
a.
6
The
Mac
ro-T
ech
Des
ign
Philo
soph
y
The
Mac
ro-T
ech
pro
duc
t lin
e, a
nd it
s p
recu
rsor
Mic
ro-T
ech®
, aw
ed th
e au
dio
ind
ustr
y w
ith n
ew
tech
nolo
gie
s th
at r
educ
ed d
isto
rtio
n an
d th
erm
al
stre
ss —
whi
le in
crea
sing
rel
iab
ility
, aud
io q
ualit
y, p
ower
den
sity
and
pow
er o
utp
ut.
Thre
e p
aten
ted
tech
nolo
gie
s in
vent
ed b
y C
row
n’s
Ger
ald
Sta
nley
led
to th
ose
ben
efi ts
:
• G
roun
ded
Brid
ge™
top
olog
y p
rovi
ded
4 ti
mes
the
pow
er o
f
exis
ting
pow
er tr
ansi
stor
s w
ithou
t sac
rifi c
ing
rel
iab
ility
.
• Ju
nctio
n Te
mp
erat
ure
Sim
ulat
ion
(JTS
), o
ther
wis
e kn
own
as O
utp
ut D
evic
e E
mul
ator
Pro
tect
ion
(OD
EP
®),
pro
tect
ed
the
pow
er tr
ansi
stor
s fr
om o
verh
eatin
g a
nd m
axim
ized
thei
r
pot
entia
l pow
er o
utp
ut b
y ke
epin
g th
em a
t the
op
timum
tem
per
atur
e.
• Va
riab
le Im
ped
ance
or
VZ
® p
ower
sup
ply
, als
o ca
lled
bi-l
evel
pow
er-s
upp
ly s
witc
hing
, was
use
d in
the
MA
-360
0VZ
and
MA
-
5000
VZ
Ser
ies.
The
sup
ply
cha
nges
its
imp
edan
ce to
ad
apt t
o
the
sig
nal v
olta
ge
and
cur
rent
. Thi
s te
chno
log
y p
erm
its la
rge
amou
nts
of p
ower
in a
com
pac
t pac
kag
e w
hile
ach
ievi
ng u
ltra-
low
dis
tort
ion
and
with
out g
ener
atin
g e
xces
s he
at.
How
It A
ll B
egan
...Th
e b
rain
stor
min
g fo
r th
is w
hole
fam
ily b
egan
with
colla
bor
atio
n b
etw
een
eng
inee
rs G
eral
d S
tanl
ey a
nd J
im
Wor
din
ger
. In
cons
ider
ing
the
dra
wb
acks
of c
urre
nt p
ower
amp
lifi e
rs, t
hey
wer
e lo
okin
g fo
r w
ays
to:
•
pac
k m
ore
pow
er in
to a
sm
alle
r ra
ck s
pac
e
•
imp
rove
rel
iab
ility
by
pre
vent
ing
ove
rhea
ting
• lo
wer
the
cost
per
wat
t.
Ger
ald
’s G
roun
ded
-Brid
ge
des
ign
and
Jun
ctio
n Te
mp
erat
ure
Sim
ulat
ion
wer
e al
read
y in
his
tool
kit.
In 1
975,
JTS
was
emp
loye
d in
the
SA
-2 a
nd P
SA
-2 a
mp
lifi e
rs, w
hile
Gro
und
ed
Brid
ge
was
use
d in
the
M-6
00.
Ger
ald
and
Jim
thou
ght
, “H
ow a
bou
t tak
ing
our
two
bes
t
tech
nolo
gie
s an
d p
uttin
g th
em in
the
sam
e p
rod
uct?
” Th
e
Mic
ro-T
ech
Ser
ies
was
bor
n. T
he o
rigin
al n
ame
of th
is s
erie
s
was
to b
e H
VA fo
r H
igh
Valu
e A
mp
lifi e
r.
How
abo
ut
taki
ng o
ur
two
best
te
chno
logi
es
and
putti
ng
them
in th
e sa
me
prod
uct?
”
7
In th
ose
day
s, C
row
n w
as
reco
gni
zed
as
a m
anuf
actu
rer
of h
ome
hi-fi
pro
duc
ts. B
ut th
e
HVA
Ser
ies
was
inte
nded
for
pro
aud
io T
ourin
g a
nd M
I, no
t
for
the
livin
g ro
om. I
t was
a n
ew
dire
ctio
n fo
r C
row
n.
Cro
wn’
s p
resi
den
t at t
hat t
ime,
Max
Sch
olfi e
ld, r
ecog
nize
d th
at
Cro
wn’
s m
arke
ting
nee
ded
to
be
shak
en u
p, s
o he
hire
d D
r.
Cla
y B
arcl
ay to
driv
e ch
ang
e
in C
row
n’s
mar
ketin
g a
nd s
ales
div
isio
ns. C
lay
real
ized
that
the
MI a
nd T
ourin
g in
dus
trie
s
need
ed a
pro
duc
t lik
e th
is, a
nd
he s
old
the
idea
to C
row
n an
d
to p
oten
tial c
usto
mer
s.
A 1
983
sche
mat
ic b
y G
eral
d S
tanl
ey o
f the
Gro
unde
d B
ridge
circ
uit.
8
Mic
ro-T
ech
Jim
and
Cla
y us
ed to
sha
re id
eas
over
lunc
h, w
here
Jim
told
Cla
y
abou
t the
con
cep
t. C
lay
cam
e up
with
the
nam
e “M
icro
-Tec
h”
bec
ause
the
goa
l was
to p
ut h
igh
tech
nolo
gy
into
a m
icro
-siz
ed
amp
. It w
as a
new
pac
kag
ing
par
adig
m a
s w
ell a
s a
new
mar
ket.
In th
e ea
rly 1
980s
, Jim
Wor
din
ger
wen
t to
Sho
wco
, one
of t
he
maj
or to
urin
g s
ound
com
pan
ies.
At t
hat t
ime
they
wer
e d
oing
soun
d fo
r D
avid
Bow
ie u
sing
PS
A p
ower
am
ps.
Acc
ord
ing
to
Jim
, “W
e as
ked
them
wha
t the
y w
ould
like
to s
ee in
an
amp
lifi e
r.”
“The
y sa
id, ‘
We’
d li
ke th
em s
mal
ler
and
low
er-c
ost.’
I co
uld
n’t
say
anyt
hing
ab
out w
hat w
e w
ere
wor
king
on,
but
thei
r co
mm
ent
cert
ainl
y vi
ndic
ated
our
des
ign
goa
ls. S
how
co w
as o
ne o
f
our
fi rst
cus
tom
ers;
they
use
d a
lot o
f Mic
ro-T
echs
. We
had
a
rela
tions
hip
with
them
. The
y w
ould
fi nd
any
pro
ble
ms
fi rst
and
then
we’
d fi
x th
em.”
Eve
ntua
lly C
lair
Bro
ther
s b
oug
ht S
how
co. N
ow th
ey a
re u
sing
over
200
0 M
A-3
600V
Zs.
The
MT-
700
(nev
er re
leas
ed)
was
the
fi rst
Mic
ro-T
ech
amp
. The
n
cam
e th
e M
T-10
00 w
hich
pro
vid
ed 1
000
wat
ts in
to 2
ohm
s. N
ext
was
the
MT-
1200
whi
ch p
rod
uced
120
0 w
atts
, tha
nks
to b
igg
er
pow
er tr
ansf
orm
ers.
The
tech
nolo
gy
in M
icro
-Tec
h p
rod
ucts
hel
ped
Cro
wn
dev
elop
amp
s fo
r M
agne
tic R
eson
ance
Imag
ing
(M
RI)
. Gen
eral
Ele
ctric
aske
d C
row
n to
mak
e am
plifi
ers
with
mor
e vo
ltag
e an
d c
urre
nt
than
wha
t was
ava
ilab
le. W
e cr
eate
d b
igg
er a
mp
s fo
r G
E, s
uch
as
the
7780
, usi
ng J
TS a
nd G
roun
ded
Brid
ge.
An
early
ske
tch
by J
im W
ordi
nger
sh
owin
g a
prop
osed
cha
ssis
layo
ut
of a
pre
-Mic
ro-T
ech
pow
er a
mpl
ifi er
.
9
Mac
ro-T
ech
Bui
ldin
g o
n ou
r ex
per
ienc
e w
ith th
e M
T se
ries,
Ger
ald
and
Jim
dev
elop
ed th
e M
acro
-Tec
h S
erie
s in
198
7. It
ad
ded
Plu
g-
In-P
roce
ssor
s (P
IP™
car
ds)
and
offe
red
a b
ette
r ap
pea
ranc
e.
Jim
Wor
din
ger
rem
emb
ers,
“In
the
early
day
s w
e’d
com
par
e
MA
am
plifi
ers
sid
e-b
y-si
de
with
com
pet
itive
am
ps.
Our
s ha
d
mor
e p
unch
and
dee
per
bas
s, w
hich
I at
trib
uted
to m
ore
outp
ut
volta
ge
and
cur
rent
.”
The
hug
e M
acro
-Tec
h 10
,000
am
plifi
er
was
bas
ical
ly a
n M
RI a
mp
mod
ifi ed
for
aud
io u
se w
ith a
new
aud
io in
terf
ace
and
fron
t pan
el.
It w
as d
evel
oped
for
John
Roy
er a
nd
Tom
Alle
bra
ndi w
ho d
id s
ound
for
the
Ind
iana
pol
is 5
00. T
hree
of t
hese
am
ps
wer
e m
odifi
ed to
driv
e th
e ra
ce tr
ack’
s
240V
dis
trib
uted
-sp
eake
r sy
stem
—
rep
laci
ng tw
o hu
ge
war
-sur
plu
s am
plifi
ers
from
a b
attle
ship
.
“We
sup
plie
d th
e fi r
st M
acro
-Tec
h
pro
toty
pes
to J
ohn
McB
ride
of M
D
Sys
tem
s, d
oing
a to
ur fo
r G
arth
Bro
oks.
At o
ne g
ig, t
he F
OH
eng
inee
r no
ted
that
he h
ad to
kee
p p
ushi
ng th
e le
vel u
p in
the
mid
rang
e. T
he p
rob
lem
was
n’t w
ith
the
amp
s. A
ctua
lly, M
D h
ad b
urne
d u
p
two-
third
s of
the
mid
rang
e d
river
s b
ecau
se
they
wer
en’t
used
to s
eein
g th
at k
ind
of p
ower
. Cro
wn
ship
ped
in 2
4 d
river
s,
inst
alle
d th
em, a
nd w
ired
them
diff
eren
tly.
Pro
ble
m s
olve
d. T
hat’s
the
kind
of s
upp
ort
Cro
wn
wou
ld d
o.”
Cro
wn
Mac
ro-T
ech
10,0
00.
...th
ey w
eren
’t us
ed to
see
ing
that
kin
d of
pow
er.”
10
In 1
992,
Cro
wn
eng
inee
r A
ndy
Arc
hias
wor
ked
on
the
MA
-500
0. C
row
n’s
upp
er m
anag
emen
t was
del
ight
ed th
at th
e am
p h
ad s
uch
a p
ositi
ve im
pac
t
on th
e co
mp
any,
the
mus
ic in
dus
try,
and
the
aud
io
wor
ld. M
A-5
000s
wer
e ev
en u
sed
on
des
troye
rs
and
airc
raft
carr
iers
(an
d s
till a
re to
day
).
A m
ajor
sup
por
ter
of M
A a
mp
s w
as S
am
Hel
ms,
man
ager
of S
igm
et, a
pre
mie
r p
ro a
udio
rep
rese
ntat
ive
in N
ew J
erse
y. S
am p
ut C
row
n
amp
s th
roug
h al
l sor
ts o
f tor
ture
test
s. A
s he
says
, “W
e p
ut lo
w-f
req
uenc
y sq
uare
wav
es in
to
the
amp
and
dro
ve a
sub
woo
fer
with
that
sig
nal.
This
was
to s
how
how
the
MA’
s d
amp
ing
fact
or
cont
rolle
d s
pea
ker-
cone
mot
ion
com
par
ed to
the
com
pet
ition
. It w
as n
o co
ntes
t.”
“Usi
ng a
sig
nal g
ener
ator
, we
put
60
Hz
in th
e
front
end
of t
he a
mp
, ran
the
leve
l con
trols
up
, got
hig
h-p
ower
out
of t
he a
mp
and
wel
ded
pie
ces
of m
etal
with
it!
Or
we’
d ta
ke a
n A
C c
ord
, cut
off
the
end
of i
t, p
ut o
n a
ban
ana
jack
, plu
g it
in th
e
bac
k of
the
amp
lifi e
r, an
d r
un a
dril
l off
it. T
he
com
pet
ition
wou
ld s
hut o
ff an
d th
e C
row
n am
p
wou
ld ju
st k
eep
goi
ng. Y
ou c
ould
dril
l thr
oug
h a
4x4
with
no
pro
ble
m a
t all.
”
Cro
wn’
s el
ite s
tud
io a
mp
lifi e
r, th
e M
acro
-
Ref
eren
ce™
, use
d th
e sa
me
mai
n b
oard
as
the
MA
-360
0VZ
, but
with
rem
ote
load
sen
sing
for
hig
her
dam
pin
g fa
ctor
. It w
as th
e b
est-
mea
surin
g
MA
-500
0s a
re u
sed
on
dest
roye
rs a
nd a
ircra
ft ca
rrie
rs.”
amp
Cro
wn
ever
mad
e. A
roun
d 1
992,
Cro
wn
intr
oduc
ed th
e
MA
-24x
6 an
d M
A-3
6x12
am
ps
with
a d
iffer
ent p
ower
rat
ing
in e
ach
chan
nel f
or b
i-am
pin
g w
oofe
rs a
nd h
orn
driv
ers.
VZ
tech
nolo
gy
(with
bi-l
evel
pow
er s
upp
ly s
witc
hing
) w
as fi
rst
pro
toty
ped
in a
n M
A-1
200.
It w
as fe
ared
that
the
switc
hing
wou
ld a
ffect
the
aud
io, b
ut th
at d
id n
ot h
app
en. T
he fi
rst
bi-l
evel
am
ps
wer
e M
RI u
nits
cus
tom
-mad
e fo
r P
icke
r
Inte
rnat
iona
l, a
med
ical
imag
ing
com
pan
y.
Jim
Ste
mb
el, C
row
n’s
Inte
rnat
iona
l Bus
ines
s D
evel
opm
ent
Man
ager
, rec
alls
: “A
t the
trad
e sh
ow in
whi
ch w
e in
trod
uced
the
MA
-360
0VZ
, it w
as th
e fi r
st a
mp
with
that
muc
h p
ower
in
two
rack
sp
aces
. One
of o
ur b
igg
est c
omp
etito
rs a
sked
, ‘W
hy
put
all
that
pow
er in
two
rack
uni
ts?’
We
rep
lied
, ‘B
ecau
se
we
coul
d.’
Tha
t pow
er d
ensi
ty w
as u
nhea
rd o
f at t
he ti
me.
It
was
qui
te a
sig
nifi c
ant l
and
mar
k.”
“Whe
n w
e in
trod
uced
the
MA
-500
0, o
ne o
f our
maj
or
cust
omer
s as
ked
, ‘W
hy d
oes
anyb
ody
need
that
muc
h
pow
er?’
Ag
ain
it w
as a
n am
plifi
er
ahea
d o
f its
tim
e —
it
was
so
larg
e co
mp
ared
to a
nyth
ing
els
e on
the
mar
ket.
At
the
time,
nob
ody
app
reci
ated
the
pow
er o
f the
MA
-500
0.
Of c
ours
e, th
e M
A-5
000
has
gon
e on
to b
ecom
e a
wild
ly
succ
essf
ul a
mp
in to
urin
g s
ound
— a
sta
ndar
d. T
hey
real
ly
wer
e tre
nd-s
ettin
g a
mp
lifi e
rs.”
10 y
ears
ag
o in
Pro
Sou
nd N
ews,
a p
oll r
epor
ted
that
9 o
ut
10 o
f the
maj
or to
urs
used
Cro
wn,
mos
tly M
A a
mp
s. W
e st
ill
have
die
-har
d c
usto
mer
s w
ho re
fuse
to u
se a
nyth
ing
els
e.
So,
sta
rtin
g w
ith G
roun
ded
Brid
ge,
inve
nted
in 1
971,
and
JTS
, inv
ente
d in
197
4, th
ose
two
key
pie
ces
of te
chno
log
y
enab
led
the
Mic
ro-T
ech
and
Mac
ro-T
ech
fam
ily. A
fter
a lo
ng
lifet
ime,
mos
t of t
hose
pro
duc
ts a
re s
till r
unni
ng. T
hat’s
wha
t
we
thin
k th
ey s
houl
d d
o.
11
Abo
ut G
eral
d St
anle
y
The
mas
term
ind
beh
ind
the
Mac
ro-T
ech
Ser
ies,
and
all C
row
n so
lid-s
tate
ele
ctro
nics
for o
ver 4
0 ye
ars,
is o
ur s
enio
r vic
e p
resi
den
t of R
&D
Ger
ald
Sta
nley
.
Ger
ald
reca
lls, “
Whe
n I w
as a
kid
I us
ed to
go
arou
nd to
neig
hbor
s to
get
old
rad
ios.
I lik
ed to
get
par
ts o
ut o
f the
m, a
nd
I lik
ed to
sou
p th
em u
p.”
Thi
s ea
rly in
tere
st in
ele
ctro
nics
led
to
an a
maz
ing
car
eer.
This
bril
liant
eng
inee
r jo
ined
Cro
wn
par
t-tim
e in
196
4, fi
rst
wor
king
as
a ta
pe-
reco
rder
tech
, dra
ftsp
erso
n an
d e
ngin
eer,
whe
n he
des
igne
d th
e S
A-2
0-20
and
SA
-60-
60 —
the
fi rst
solid
-sta
te C
row
n am
plifi
ers
. In
1965
he
rece
ived
a B
SE
from
Mic
hig
an S
tate
(H
onor
s C
olle
ge)
and
MS
E fr
om th
e U
nive
rsity
of M
ichi
gan
in 1
966
(Sta
te C
olle
ge
Fello
wsh
ip).
Ger
ald
has
this
to s
ay a
bou
t the
SA
-60-
60:
“It w
as a
dua
l 60W
8-oh
m a
mp
lifi e
r. O
nly
a fe
w w
ere
mad
e. T
hey
wer
e un
relia
ble
,
usin
g o
nly
hig
h-sp
eed
fuse
s fo
r p
rote
ctio
n. T
he S
A-2
0-20
was
a 1-
rack
-sp
ace
amp
that
soo
n b
ecam
e th
e S
A-3
0-30
. The
SA
-
20-2
0 us
ed s
mal
ler
vers
ions
of t
he S
A-6
0-60
out
put
dev
ices
.
The
60-6
0 w
as D
C c
oup
led
thro
ugho
ut a
nd th
e 20
-20
was
AC
coup
led
at t
he in
put
. The
DC
-300
was
not
the
fi rst
DC
aud
io
amp
, but
it w
as th
e fi r
st th
at w
as re
liab
le.”
Ger
ald
wen
t on
to in
vent
the
tech
nolo
gy
beh
ind
all
of C
row
n’s
pow
er a
mp
ser
ies.
He
hold
s a
hug
e nu
mb
er o
f pat
ents
: 31
in
the
U.S
. alo
ne, a
nd m
any
mor
e in
oth
er c
ount
ries.
Ger
ald
com
men
ts o
n C
row
n’s
succ
ess
over
the
year
s:
In a
n er
a of
co
okbo
ok
desi
gns
and
bugg
y so
ftwar
e, it
wou
ld
seem
that
the
mos
t ba
sic
less
ons
of
hist
ory
have
bee
n fo
rgot
ten.
Cro
wn’
s re
cipe
is s
impl
e:
desi
gn, b
uild
and
se
rvic
e ea
ch p
rodu
ct
as if
you
wer
e th
e cu
stom
er. T
his
appr
oach
not
onl
y dr
ives
the
prod
uct t
o ex
celle
nce,
it d
rive
s th
e pe
ople
to b
e th
e be
st th
at th
ey c
an b
e.”
Cro
wn’
s V
ice
Pre
side
nt o
f Res
earc
h an
d D
evel
opm
ent,
Ger
ald
Sta
nley
.
12
Mac
ro-T
ech
Adv
ance
d Fe
atur
esTh
e M
acro
-Tec
h S
erie
s em
plo
ys a
num
ber
of i
nnov
ativ
e, p
aten
ted
tech
nolo
gie
s. L
et’s
look
at t
hem
in d
etai
l.
IOC
® (
Inpu
t Out
put C
ompa
rato
r)
The
IOC
circ
uit c
omp
ares
the
outp
ut s
igna
l of t
he a
mp
lifi e
r w
ith
the
inp
ut s
igna
l. If
ther
e is
any
diff
eren
ce o
ther
than
gai
n, th
en it
is c
onsi
der
ed d
isto
rtio
n an
d th
e IO
C in
dic
ator
fl as
hes.
Thi
s LE
D
light
s w
hene
ver
ther
e is
dis
tort
ion
of 0
.05%
or
mor
e. (
Not
e th
at
amp
lifi e
r cl
ipp
ing
is ty
pic
ally
clo
se to
3%
TH
D.)
An
IOC
con
diti
on
also
is s
ense
d b
y an
IQ-P
IP m
odul
e in
stal
led
in P
IP-c
omp
atib
le
amp
lifi e
rs.
IOC
is d
esig
ned
to re
por
t any
form
of d
isto
rtio
n. IO
C n
ot o
nly
chec
ks th
e w
avef
orm
for
dis
tort
ion,
but
als
o re
por
ts in
put
over
load
and
eve
n a
pro
tect
ive
actio
n th
at m
utes
or
shut
s d
own
an a
mp
lifi e
r. W
ith a
ll of
thes
e fe
atur
es, I
OC
mon
itors
the
entir
e
amp
lifi e
r. W
hen
the
IOC
ind
icat
or is
off,
the
amp
lifi e
r is
defi
nite
ly
oper
atio
nal a
nd u
ndis
tort
ed. I
OC
pro
vid
es a
real
-tim
e p
roof
of
per
form
ance
.
Out
put D
evic
e E
mul
atio
n P
rote
ctio
n (O
DE
P)
Ger
ald
inve
nted
OD
EP
to s
olve
two
long
-sta
ndin
g p
rob
lem
s w
ith
amp
lifi e
r d
esig
ns:
• P
reve
ntin
g a
mp
lifi e
r sh
utd
own
dur
ing
dem
and
ing
op
erat
ion,
and
• In
crea
sing
the
effi c
ienc
y of
the
outp
ut tr
ansi
stor
s.
OD
EP
lim
its th
e si
gna
l whe
n ne
cess
ary
to p
reve
nt o
verh
eatin
g
and
failu
re o
f the
am
plifi
er
outp
ut tr
ansi
stor
s. C
row
n en
gin
eers
esta
blis
hed
a r
igor
ous
pro
gra
m to
mea
sure
the
safe
op
erat
ing
area
(S
OA
) —
rela
ted
to te
mp
erat
ure
— o
f eac
h ou
tput
tran
sist
or
bef
ore
inst
allin
g it
in a
n am
plifi
er.
Ger
ald
als
o d
esig
ned
inte
llig
ent
circ
uitr
y to
sim
ulat
e th
e in
stan
tane
ous
oper
atin
g c
ond
ition
s of
thos
e ou
tput
tran
sist
ors.
Its
nam
e d
escr
ibes
wha
t it d
oes:
Out
put
Dev
ice
Em
ulat
ion
Pro
tect
ion
or O
DE
P. It
not
onl
y si
mul
ates
the
oper
atio
n of
the
outp
ut tr
ansi
stor
s b
ut it
als
o co
mp
ares
thei
r
oper
atio
n to
thei
r kn
own
SO
A. I
f mor
e p
ower
is a
bou
t to
be
aske
d
of th
e ou
tput
dev
ices
than
they
are
cap
able
of d
eliv
erin
g u
nder
the
pre
sent
con
diti
ons,
OD
EP
imm
edia
tely
lim
its th
e d
rive
leve
l
until
it fa
lls w
ithin
the
SO
A. L
imiti
ng is
pro
por
tiona
l and
kep
t to
an a
bso
lute
min
imum
— o
nly
wha
t is
req
uire
d to
pre
vent
out
put
tran
sist
or d
amag
e.
Whe
n O
DE
P li
miti
ng b
egin
s, th
e IO
C c
ircui
try
will
see
that
the
inp
ut w
avef
orm
doe
s no
t mat
ch th
e ou
tput
wav
efor
m, a
nd a
n er
ror
sig
nal i
s g
ener
ated
. If t
he c
omp
ress
ors
are
on, t
hey
will
see
the
erro
r si
gna
l and
com
pre
ss th
e in
put
sig
nal t
o co
rrec
t the
pro
ble
m.
Whe
n th
is h
app
ens,
ther
e is
no
aud
ible
sig
nal d
egra
dat
ion.
Com
pre
ssio
n is
sub
tle, a
nd n
ot n
otic
eab
le u
nles
s th
e sy
stem
is
driv
en to
ext
rem
ely
hig
h le
vels
.
How
doe
s O
DE
P li
miti
ng in
crea
se th
e ef
fi cie
ncy
of th
e ou
tput
tran
sist
ors?
It k
eep
s th
em a
t the
op
timum
tem
per
atur
e.
The
tran
sist
ors
are
neith
er o
verh
eate
d, n
or o
verp
rote
cted
.
Ove
rpro
tect
ing
resu
lts in
tran
sist
ors
not b
eing
driv
en to
thei
r fu
ll
outp
ut le
vel.
In s
hort
, OD
EP
ena
ble
s th
e am
plifi
er
to u
se th
e ou
tput
tran
sist
ors
mor
e ef
fi cie
ntly
whi
le g
reat
ly in
crea
sing
thei
r re
liab
ility
.
Fina
lly, t
he s
tatu
s of
OD
EP
is m
onito
red
in tw
o w
ays.
Firs
t, th
e fro
nt
pan
el O
DE
P in
dic
ator
s sh
ow w
heth
er th
e am
plifi
er
is fu
nctio
ning
corr
ectly
or
if O
DE
P is
lim
iting
the
driv
e le
vel.
Sec
ond
, OD
EP
dat
a
is fe
d to
the
PIP
con
nect
or a
t the
bac
k of
the
amp
lifi e
r so
ad
vanc
ed
One
of G
eral
d S
tanl
ey’s
man
y pa
tent
s.
13
PIP
mod
ules
like
the
IQ-P
IP-U
SP
3 ca
n us
e it
to m
ake
dec
isio
ns a
nd
cont
rol t
he a
mp
lifi e
r. W
ith O
DE
P y
ou g
et th
e m
axim
um p
ower
with
the
max
imum
pro
tect
ion
— th
e sh
ow g
oes
on!
Gro
unde
d B
ridg
e C
row
n’s
Gro
und
ed B
ridg
e to
pol
ogy
mak
es th
e am
plifi
er
del
iver
pea
k-to
-pea
k vo
ltag
es to
the
load
that
are
twic
e th
e vo
ltag
e se
en
by
the
outp
ut d
evic
es a
nd tw
ice
the
volta
ge
gen
erat
ed b
y th
e
pow
er s
upp
lies.
In o
ther
wor
ds,
the
amp
lifi e
r ca
n p
rod
uce
loud
er
soun
d w
ithou
t stre
ssin
g th
e ou
tput
tran
sist
ors.
The
resu
lts a
re
hig
her
effi c
ienc
y, lo
wer
dis
tort
ion
and
sup
erio
r re
liab
ility
.
Cla
ss A
B+
BC
row
n in
vent
ed th
e C
lass
AB
+B
am
plifi
er
des
ign,
whi
ch p
rovi
des
bot
h hi
gh
effi c
ienc
y an
d lo
w d
isto
rtio
n. A
B+
B c
ircui
try
dra
ws
less
AC
pow
er a
nd w
aste
s le
ss h
eat t
han
Cla
ss A
, and
has
less
dis
tort
ion
than
Cla
ss B
or
Cla
ss A
B. T
o ex
pla
in h
ow A
B+
B w
orks
,
fi rst
we
need
to e
xplo
re o
ther
am
plifi
er
clas
ses.
Aud
io p
ower
am
plifi
ers
are
cla
ssifi
ed p
rimar
ily b
y th
e d
esig
n of
the
outp
ut s
tag
e (t
he tr
ansi
stor
s an
d re
late
d c
ircui
try
that
sen
d
sig
nals
to th
e lo
udsp
eake
rs).
Cla
ssifi
catio
n is
bas
ed o
n th
e
amou
nt o
f tim
e th
e ou
tput
dev
ices
(p
ower
tran
sist
ors)
are
mad
e
to o
per
ate
dur
ing
eac
h cy
cle
of th
e si
gna
l. A
mp
lifi e
r cl
asse
s ar
e
also
defi
ned
in te
rms
of o
utp
ut b
ias
curr
ent (
the
amou
nt o
f cur
rent
fl ow
ing
in th
e ou
tput
dev
ices
with
no
sig
nal p
rese
nt).
In C
lass
A o
per
atio
n, b
oth
outp
ut tr
ansi
stor
s co
nduc
t con
tinuo
usly
for
the
entir
e cy
cle
of s
igna
l sw
ing
, so
the
bia
s cu
rren
t fl o
ws
in th
e ou
tput
dev
ices
at a
ll tim
es. B
oth
dev
ices
are
alw
ays
on.
Cla
ss A
am
plifi
ers
are
sin
gle
-end
ed d
esig
ns w
ith e
ither
PN
P o
r
NP
N o
utp
ut d
evic
es. C
lass
A is
the
mos
t ine
ffi ci
ent o
f all
pow
er
Gro
un
ded
Bri
dg
e th
eory
for
elec
tro
nic
s-sa
vvy
read
ers
The
pow
er-s
upp
ly b
ridg
e re
ctifi
er is
not
gro
und
re
fere
nced
, and
the
tran
sfor
mer
sec
ond
ary
is n
ot c
ente
r-ta
pp
ed. T
his
allo
ws
the
pow
er s
upp
ly to
del
iver
+V
CC
an
d -
VC
C fr
om th
e sa
me
brid
ge
rect
ifi er
and
fi lte
r as
a
tota
l diff
eren
ce in
pot
entia
l reg
ard
less
of t
heir
volta
ges
w
ith r
esp
ect t
o g
roun
d.
Com
pos
ite o
utp
ut d
evic
es a
re a
rran
ged
to fu
nctio
n as
g
igan
tic N
PN
and
PN
P d
evic
es. E
ach
outp
ut s
tag
e ha
s tw
o co
mp
osite
NP
N a
nd tw
o co
mp
osite
PN
P d
evic
es.
The
dev
ices
con
nect
ed to
the
load
are
ref
erre
d to
as
“hig
h-si
de
NP
N a
nd P
NP
” an
d th
e d
evic
es c
onne
cted
to
gro
und
are
ref
erre
d to
as
“low
-sid
e N
PN
and
PN
P.”
Pos
itive
cur
rent
is d
eliv
ered
to th
e lo
ad b
y in
crea
sing
co
nduc
tanc
e si
mul
tane
ousl
y in
the
hig
h-si
de
NP
N a
nd
low
-sid
e P
NP
sta
ge,
whi
le d
ecre
asin
g c
ond
ucta
nce
of
the
hig
h-si
de
PN
P a
nd lo
w-s
ide
NP
N in
syn
chro
ny.
Imag
ine
a g
rap
h of
cur
rent
ver
sus
volta
ge
(I v
ersu
s V
) in
an
out
put
sta
ge
of a
pow
er a
mp
lifi e
r. Th
is g
rap
h ha
s fo
ur
qua
dra
nts:
+V
and
+I,
-V a
nd +
I, –V
and
–I,
+V
and
–I.
Gro
und
ed B
ridg
e is
a fo
ur-q
uad
rant
am
plifi
er
top
olog
y.
Res
istiv
e lo
ads
only
use
the
fi rst
and
third
qua
dra
nts
(+V,
+
I and
-V,
–I)
. R
eact
ive
load
s al
so u
se th
e se
cond
and
fo
urth
qua
dra
nts
(–V,
+I a
nd +
V, –
I).
amp
lifi e
r d
esig
ns, a
vera
gin
g
only
20%
. Bec
ause
of t
his,
Cla
ss A
am
plifi
ers
are
larg
e,
heav
y an
d r
un v
ery
hot.
That
is b
ecau
se th
e am
p
runs
con
stan
tly a
t ful
l pow
er.
On
the
othe
r ha
nd, C
lass
A
des
igns
hav
e th
e le
ast a
mou
nt
of d
isto
rtio
n.
Cla
ss B
op
erat
ion
is th
e
opp
osite
of C
lass
A. B
oth
outp
ut d
evic
es a
re n
ever
allo
wed
to b
e on
at t
he s
ame
time.
The
bia
s is
set
so
that
curr
ent fl
ow
in a
sp
ecifi
c
outp
ut d
evic
e is
zer
o w
hen
not s
timul
ated
with
an
inp
ut
sig
nal.
Eac
h ou
tput
dev
ice
is o
n fo
r ex
actly
one
hal
f of
a co
mp
lete
sin
usoi
dal
sig
nal
cycl
e. D
ue to
this
op
erat
ion,
Cla
ss B
des
igns
sho
w h
igh
effi c
ienc
y, b
ut p
oor
linea
rity
arou
nd th
e cr
osso
ver
reg
ion.
This
is b
ecau
se it
take
s tim
e
to tu
rn o
ne d
evic
e of
f and
the
othe
r d
evic
e on
, cau
sing
ext
rem
e cr
osso
ver
dis
tort
ion.
All
of
this
rest
ricts
Cla
ss B
des
igns
to a
pp
licat
ions
with
low
pow
er
cons
ump
tion,
suc
h as
bat
tery
op
erat
ed tw
o-w
ay r
adio
s an
d
othe
r co
mm
unic
atio
ns e
qui
pm
ent.
14
Cla
ss A
B o
per
atio
n al
low
s b
oth
dev
ices
to b
e on
at t
he s
ame
time
(as
in C
lass
A),
but
just
bar
ely.
The
out
put
bia
s is
set
so
that
cur
rent
fl ow
s in
a s
pec
ifi c
outp
ut d
evic
e ap
pre
ciab
ly m
ore
than
a h
alf c
ycle
, but
less
than
the
entir
e cy
cle.
Tha
t is,
onl
y a
little
cur
rent
is a
llow
ed to
fl ow
thro
ugh
bot
h d
evic
es —
unl
ike
the
com
ple
te lo
ad c
urre
nt o
f Cla
ss A
des
igns
— b
ut e
noug
h cu
rren
t
to k
eep
eac
h d
evic
e op
erat
ing
so
they
res
pon
d in
stan
tly to
inp
ut v
olta
ge
dem
and
s. T
hus
the
inhe
rent
non
-line
arity
of C
lass
B d
esig
ns is
elim
inat
ed, w
ithou
t the
gro
ss in
effi c
ienc
ies
of th
e
Cla
ss A
des
ign.
It is
this
com
bin
atio
n of
goo
d e
ffi ci
ency
(ar
ound
50%
) w
ith e
xcel
lent
line
arity
that
mak
es C
lass
AB
the
mos
t
pop
ular
aud
io a
mp
lifi e
r d
esig
n.
Cla
ss A
B+
B d
esig
n in
volv
es tw
o p
airs
of o
utp
ut d
evic
es. O
ne
pai
r op
erat
es C
lass
AB
, whi
le th
e ot
her
(sla
ve)
pai
r op
erat
es
Cla
ss B
. Cla
ss A
B+
B d
esig
ns a
re ju
st a
s ef
fi cie
nt a
s C
lass
AB
,
but
hav
e ev
en le
ss d
isto
rtio
n.
To s
umm
ariz
e, A
B+
B c
ircui
try
dra
ws
less
AC
pow
er a
nd w
aste
s
less
hea
t tha
n C
lass
A, a
nd h
as le
ss d
isto
rtio
n th
an C
lass
B o
r
Cla
ss A
B.
Var
iabl
e Im
peda
nce
(VZ
) V
Z is
the
nam
e of
Cro
wn’
s p
aten
ted
bi-l
evel
pow
er s
upp
ly
tech
nolo
gy.
It a
llow
s C
row
n to
pac
k la
rge
amou
nts
of p
ower
into
a
com
pac
t pac
kag
e w
hile
ach
ievi
ng u
ltra-
low
dis
tort
ion
and
with
out
gen
erat
ing
exc
essi
ve h
eat.
An
amp
lifi e
r p
ower
sup
ply
mus
t be
larg
e en
oug
h
to h
and
le b
oth
the
max
imum
vol
tag
e an
d
max
imum
cur
rent
the
amp
lifi e
r ne
eds
to d
rive
its r
ated
pow
er in
to a
sp
ecifi
ed lo
ad. I
n or
der
to m
eet t
his
req
uire
men
t, m
ost c
onve
ntio
nal
sup
plie
s ar
e he
avy,
larg
e, a
nd p
rod
uce
lots
of h
eat.
In c
ontr
ast,
the
VZ
sup
ply
get
s m
ore
curr
ent A
ND
vol
tag
e ou
t of a
sm
alle
r, lig
hter
, and
mor
e ef
fi cie
nt p
acka
ge
by
dyn
amic
ally
ad
aptin
g
to b
oth
sig
nal a
nd lo
ad re
qui
rem
ents
in re
al-
time.
Thi
s p
rovi
des
the
bes
t pow
er m
atch
to th
e
wid
est r
ang
e of
load
s.
The
VZ
pow
er s
upp
ly is
div
ided
into
two
seg
men
ts. W
hen
the
outp
ut s
tag
e re
qui
res
hig
h
volta
ge,
the
seg
men
ts a
re a
rran
ged
in s
erie
s to
del
iver
twic
e th
e vo
ltag
e of
a s
ing
le s
egm
ent.
Whe
n th
e ou
tput
sta
ge
req
uire
s hi
gh
curr
ent,
the
seg
men
ts a
re a
rran
ged
in p
aral
lel t
o d
eliv
er
twic
e th
e cu
rren
t of a
sin
gle
seg
men
t.
Sen
sing
circ
uitr
y “w
atch
es”
the
volta
ge
of th
e
sig
nal t
o d
eter
min
e w
hen
to s
witc
h V
Z m
odes
.
The
pow
er s
upp
ly c
ontin
uous
ly a
dap
ts to
the
outp
ut s
igna
l: hi
gh
volta
ge
or h
igh
curr
ent.
The
switc
hing
circ
uitr
y is
des
igne
d to
pre
vent
aud
ible
sw
itchi
ng d
isto
rtio
n to
yie
ld th
e hi
ghe
st
pos
sib
le d
ynam
ic tr
ansf
er fu
nctio
n.
It al
low
s C
row
n to
pac
k la
rge
amou
nts
of p
ower
in
to a
com
pact
pa
ckag
e...”
A C
ircui
t Dia
gram
from
the
VZ
Pat
ent.
15
Nor
mal
ly, t
he p
ower
sup
plie
s op
erat
e in
the
hig
h-cu
rren
t (lo
w-im
ped
ance
)
mod
e fo
r m
axim
um th
erm
al e
ffi ci
ency
. Whe
n th
e vo
ltag
e d
eman
d s
pik
es, t
he
sup
plie
s q
uick
ly s
hift
into
hig
h-vo
ltag
e (h
igh-
imp
edan
ce)
mod
e. B
ecau
se
volta
ge
and
cur
rent
req
uire
men
ts v
ary
with
the
outp
ut le
vel a
nd fr
eque
ncy
cont
ent o
f the
sou
rce
sig
nals
, the
pow
er s
upp
lies
are
des
igne
d to
be
able
to
cont
inua
lly s
witc
h b
etw
een
the
two
mod
es a
s ne
eded
with
no
deg
rad
atio
n
to th
e au
dio
sig
nal.
With
VZ
, you
get
not
onl
y m
axim
um p
ower
, but
als
o th
e
bes
t pow
er m
atch
ing
to y
our
load
.
ILoa
d/IL
imit
(MA
-500
0)Th
is L
ED
ind
icat
es th
e m
axim
um re
al-w
orld
load
that
you
can
put
on
your
amp
lifi e
r. Th
e IL
oad
/ILim
it fe
atur
e is
des
igne
d to
hel
p y
ou g
et th
e m
axim
um
pow
er o
ut o
f you
r am
plifi
er.
In th
e re
al w
orld
, lou
dsp
eake
r im
ped
ance
var
ies
with
freq
uenc
y, a
nd lo
udsp
eake
r im
ped
ance
rat
ing
s ar
e on
ly a
pp
roxi
mat
ions
.
With
out I
Load
/ILim
it, y
ou h
ave
to d
o so
me
leng
thy
calc
ulat
ions
to
app
roxi
mat
e th
e m
axim
um n
umb
er o
f lou
dsp
eake
rs y
ou c
an d
rive
with
the
amp
lifi e
r —
and
this
doe
s no
t allo
w fo
r a
4-oh
m lo
udsp
eake
r w
hose
imp
edan
ce d
rop
s b
elow
2 o
hms
at 8
0 H
z.
This
is w
hy y
our
amp
lifi e
r ha
s IL
oad
/ILim
it. T
he IL
oad
func
tion
turn
s a
chan
nel’s
ILoa
d/IL
imit
ind
icat
or g
reen
whe
n it
sens
es th
at c
urre
nt is
fl ow
ing
to
the
load
. The
ILim
it fu
nctio
n tu
rns
the
ind
icat
or re
d w
hen
it re
ache
s m
axim
um
curr
ent o
utp
ut. T
his
mak
es it
pos
sib
le to
con
nect
real
loud
spea
kers
and
cond
uct r
ealis
tic te
sts
to fi
nd th
e m
axim
um n
umb
er o
f lou
dsp
eake
rs th
at
shou
ld b
e co
nnec
ted
. To
do
a te
st li
ke th
is, y
ou c
an o
per
ate
und
er w
orst
-
case
con
diti
ons
and
con
tinue
to c
onne
ct a
dd
ition
al lo
udsp
eake
rs in
par
alle
l
with
eac
h ou
tput
unt
il th
e IL
oad
/ILim
it in
dic
ator
turn
s re
d. T
he o
ptim
um lo
ad
is a
chie
ved
bef
ore
the
ILoa
d/IL
imit
ind
icat
or tu
rns
red
, so
dis
conn
ectin
g th
e
last
ad
ded
loud
spea
ker
giv
es y
ou a
n op
timiz
ed lo
ad.
16
Loud
spea
ker
Offs
et In
tegr
atio
nLo
udsp
eake
r O
ffset
Inte
gra
tion
(LO
I) p
rote
cts
spea
kers
from
dam
agin
g a
sym
met
rical
wav
efor
ms,
DC
and
ultr
ason
ic
sig
nals
. LO
I circ
uits
use
dou
ble
inte
gra
ting
fi lte
rs in
the
amp
lifi e
r’s fe
edb
ack
circ
uitr
y to
pro
tect
loud
spea
kers
in
seve
ral d
iffer
ent w
ays.
Firs
t, th
ey c
ente
r as
ymm
etric
al a
udio
wav
efor
ms
that
cau
se o
ff-ce
nter
woo
fer
cone
mov
emen
t. O
ff-
cent
er c
one
mov
emen
t inc
reas
es lo
udsp
eake
r he
atin
g a
nd
dis
tort
ion
whi
le re
duc
ing
the
loud
spea
ker’s
pow
er h
and
ling
abili
ty. S
econ
d, L
OI fi
lter
s un
wan
ted
DC
and
sub
soni
c
freq
uenc
ies
usin
g a
third
-ord
er B
utte
rwor
th fi
lter
with
a 3
5-
Hz
corn
er fr
eque
ncy.
Thi
rd, L
OI fi
lter
s un
wan
ted
ultr
ason
ic
freq
uenc
ies
(RF)
that
can
cau
se tw
eete
r b
urno
ut u
sing
a
seco
nd-o
rder
Bes
sel fi
lter
with
a 5
0-kH
z co
rner
freq
uenc
y.
LOI d
oes
NO
T p
rote
ct lo
udsp
eake
rs fr
om la
rge
tran
sien
t
volta
ges
or
exce
ssiv
e p
ower
leve
ls fo
r p
rolo
nged
per
iod
s of
time.
For
info
rmat
ion
on te
chni
que
s to
pro
tect
loud
spea
kers
,
refe
r to
the
Cro
wn
Am
plifi
er
Ap
plic
atio
n G
uid
e, a
vaila
ble
onl
ine
at w
ww
.cro
wna
udio
.com
.
PIP
™ M
odul
es
PIP
(P
rog
ram
mab
le In
put
Pro
cess
or)
mod
ules
pro
vid
e fe
atur
es
that
can
be
add
ed to
cus
tom
ize
the
amp
lifi e
r. P
IP m
odul
es
plu
g in
to th
e co
nnec
tor
insi
de
the
bac
k p
anel
of t
he a
mp
lifi e
r.
Feat
ures
ran
ge
from
err
or-d
riven
com
pre
ssor
/lim
iters
to re
mot
e
cont
rol a
nd m
onito
ring
via
Sys
tem
Arc
hite
ct o
r IQ
wic
™.
Your
am
plifi
er
is a
PIP
2 a
mp
lifi e
r, w
hich
mea
ns it
can
take
adva
ntag
e of
the
man
y ad
vanc
ed fe
atur
es fo
und
in P
IP2
mod
ules
, as
wel
l as
all s
tand
ard
PIP
mod
ules
. Vis
it th
e C
row
n
web
site
at w
ww
.cro
wna
udio
.com
, or
cont
act C
row
n C
usto
mer
Ser
vice
, for
des
crip
tions
of a
vaila
ble
PIP
and
PIP
2 m
odul
es.
Ref
eren
ce a
rtic
les
on
Mac
ro-T
ech
ampl
ifi er
te
chno
logy
Go
to th
e C
row
n w
ebsi
te’s
Am
plifi
er
Tech
nica
l Inf
orm
atio
n
pag
e at
this
ad
dre
ss:
http
://w
ww
.cro
wna
udio
.com
/am
p_
htm
/am
pinf
o.ht
m.
Und
er th
e he
adin
g “
Oth
er C
row
n
Am
plifi
er
Tech
nolo
gie
s” c
heck
out
thes
e ar
ticle
s:
• IO
C D
isto
rtio
n D
etec
tor
• U
nder
stan
din
g D
amp
ing
Fac
tor
• G
roun
ded
Brid
ge
Top
olog
y
• O
DE
P (
Out
put
Dev
ice
Em
ulat
or
Pro
tect
ion)
.
In th
e 19
90s,
nea
rly 9
out
of 1
0 m
ajor
tour
ing
com
pani
es c
hose
M
acro
-Tec
h am
plifi
ers
to p
ower
thei
r so
und
syst
ems.
17
• 19
71: G
eral
d S
tanl
ey in
vent
s G
roun
ded
Brid
ge
top
olog
y.
• 19
74: G
eral
d in
vent
s Ju
nctio
n Te
mp
erat
ure
Sim
ulat
ion
(JTS
).
• 19
75: M
-600
was
the
fi rst
am
p to
use
Gro
und
ed B
ridg
e. S
A-2
and
PS
A-2
fi rs
t use
d J
TS.
• 19
84: M
T-10
00 w
as th
e fi r
st c
omb
inat
ion
of G
roun
ded
Brid
ge
and
JTS
, and
Cro
wn’
s fi r
st a
mp
inte
nded
for
the
MI a
nd
Tour
ing
Sou
nd m
arke
ts.
• 19
85: M
T-12
00 w
as a
hig
her
pow
er v
ersi
on o
f MT-
1000
. MT-
600
also
was
rel
ease
d. M
T-12
00LX
and
MT-
600L
X h
ad a
fanc
y
extr
uded
fron
t pan
el a
nd m
ore
dis
pla
ys.
• 19
86: M
A-1
0K p
rovi
des
10,
000
wat
ts o
f pow
er. T
he fi
rst M
A-
10K
ap
plic
atio
n is
to p
ower
465
sp
eake
rs a
t the
Ind
iana
pol
is
500
Mot
or S
pee
dw
ay.
• 19
87: M
A-1
200
and
MA
-600
(w
ith P
IP p
anel
s).
• 19
91: M
A-3
600V
Z fe
atur
ing
Var
iab
le Im
ped
ance
(V
Z)
bi-l
evel
pow
er s
upp
ly s
witc
hing
. VZ
tech
nolo
gy
was
fi rs
t pro
toty
ped
in a
n M
A-1
200.
The
fi rs
t bi-l
evel
am
ps
wer
e M
RI u
nits
cus
tom
-
mad
e fo
r P
icke
r.
• 19
92: M
A-5
000V
Z a
lso
feat
ures
Var
iab
le Im
ped
ance
.
MA
-360
0VZ
and
MA
-500
0VZ
qui
ckly
bec
ome
the
tour
ing
stan
dar
ds.
MA
-24x
6 an
d M
A-3
6x12
for
bi-a
mp
ing
are
intr
oduc
ed.
• 19
99: M
A-6
02, 1
202,
240
2 an
d M
A-5
002V
Z.
Cro
wn
Am
plif
iers
Tim
e Li
ne
VZ
th
eory
for
elec
tro
nic
s-sa
vvy
read
ers
VZ
offe
rs a
sim
ple
way
to a
pp
ly C
lass
-H o
per
atio
n to
a
Gro
und
ed B
ridg
e ci
rcui
t. C
lass
H c
hang
es th
e p
ower
su
pp
ly v
olta
ge
from
a lo
wer
leve
l to
a hi
ghe
r le
vel
whe
n la
rger
out
put
sw
ing
s ar
e re
qui
red
. Cla
ss H
als
o m
odul
ates
the
hig
her
pow
er-s
upp
ly v
olta
ge
by
the
inp
ut
sig
nal.
This
allo
ws
the
pow
er s
upp
ly to
trac
k th
e au
dio
in
put
and
pro
vid
e ju
st e
noug
h vo
ltag
e fo
r op
timum
op
erat
ion
of th
e ou
tput
dev
ices
.
The
Gro
und
ed B
ridg
e ha
s a
par
ticul
arly
sim
ple
sup
ply
ne
eded
for
Cla
ss H
in th
at o
nly
one
sup
ply
nee
ds
to b
e ra
il sw
itche
d, w
here
as a
com
mon
hal
f-b
ridg
e (t
otem
-p
ole)
out
put
sta
ge
need
s tw
o su
ch s
witc
hed
sup
plie
s p
er c
hann
el. T
he b
i-lev
el (
VZ
) su
pp
ly is
furt
her
eleg
ant
in th
at th
e p
ower
sup
ply
is a
lway
s fu
lly u
tiliz
ed in
bot
h hi
gh-
and
low
-vol
tag
e co
nfi g
urat
ions
. No
seg
men
ts o
f th
e p
ower
sup
ply
are
was
ted
.
Am
p ro
om a
t Soo
Youn
g R
o C
hurc
h in
Pus
an, S
outh
Kor
ea.
18
A p
age
from
Aud
io E
ngin
eerin
g S
ocie
ty P
repr
int 9
59 (
N-1
),
“Wha
t Wat
t in
Am
plifi
er T
estin
g” b
y G
eral
d S
tanl
ey a
nd
Rob
ert M
cLau
ghlin
.
An
early
ske
tch
of a
Mic
ro-T
ech
sche
mat
ic b
y Ji
m W
ordi
nger
.
19
Rig
ht: P
roto
type
test
dat
a fr
om 1
984
and
1986
.
Har
man
Pro
Gro
up P
resi
dent
Bla
ke A
ugsb
urge
r (le
ft) a
nd
Cro
wn
Pre
side
nt M
ark
Gra
ham
(rig
ht)
disp
lay
Ger
ald’
s la
test
pa
tent
pla
ques
in a
rec
ent C
row
n as
sem
bly
mee
ting.
A m
id-1
960s
sho
t of G
eral
d S
tanl
ey.
20
The
Mac
ro-T
ech
Ser
ies
cont
inue
s
to b
uild
on
Cro
wn’
s le
gen
dar
y
rep
utat
ion
as th
e in
dus
try
refe
renc
e
for
soni
c p
urity
, pow
er a
nd d
urab
ility
. Unm
atch
ed
in th
e m
arke
tpla
ce, M
acro
-Tec
h p
rovi
des
the
exce
llenc
e an
d re
liab
ility
that
ind
ustr
y
pro
fess
iona
ls s
take
thei
r re
put
atio
ns o
n tim
e af
ter
time.
And
with
goo
d re
ason
. Cro
wn
amp
lifi e
rs a
re
des
igne
d to
take
the
heav
y us
e of
pro
fess
iona
l
soun
d re
info
rcem
ent d
ay in
and
day
out
with
out
failu
re —
or
colo
ring
the
soun
d. W
hen
it co
mes
to d
eliv
erin
g th
e p
ures
t sig
nal t
rans
fer
pos
sib
le,
noth
ing
els
e b
eats
a M
acro
-Tec
h.
Sup
erio
r E
ngin
eerin
g F
or S
uper
ior
Per
form
ance
Our
am
plifi
ers
are
eng
inee
red
with
the
phi
loso
phy
of p
rod
ucin
g th
e ve
ry b
est s
ound
pos
sib
le u
nder
bot
h no
rmal
and
ext
rem
e
oper
atio
n co
nditi
ons.
To
achi
eve
this
, our
eng
inee
rs e
xam
ined
all
the
fact
ors
in a
mp
lifi e
r
des
ign
and
op
erat
ion.
The
resu
lt is
a n
umb
er o
f
pat
ente
d C
row
n ci
rcui
t des
igns
that
allo
w th
e
Mac
ro-T
ech
Ser
ies
to a
chie
ve s
onic
pur
ity a
nd
relia
bili
ty th
at C
row
n is
kno
wn
for
arou
nd th
e
wor
ld. T
his
des
ign
phi
loso
phy
, com
bin
ed w
ith
Cro
wn’
s co
mm
itmen
t to
exce
llenc
e in
des
ign,
man
ufac
turin
g a
nd s
ervi
ce, i
s w
hat m
akes
Mac
ro-T
ech
the
choi
ce fo
r p
rofe
ssio
nal s
ound
rein
forc
emen
t.
Ver
satil
e, E
arth
-Sha
king
Pow
erN
o ot
her
amp
lifi e
r ca
n g
ive
you
as m
uch
vers
atili
ty in
del
iver
ing
ear
th-s
haki
ng p
ower
as
Mac
ro-T
ech.
Thr
oug
h th
e p
aten
ted
Gro
und
ed-
Brid
ge
circ
uitr
y an
d M
ulti-
Mod
e (A
, AB
+ B
)
circ
uitr
y, e
ach
Mac
ro-T
ech
can
driv
e hi
gh
outp
ut
leve
ls in
to m
assi
ve lo
ads
whi
le a
chie
ving
the
low
est d
isto
rtio
n an
d g
reat
est r
elia
bili
ty.
The
Gro
und
ed B
ridg
e ut
ilize
s ou
tput
tran
sist
ors
in a
ver
y ef
fi cie
nt fo
ur-q
uad
rant
brid
ge
whi
ch
is im
mun
e to
dyn
amic
cro
ssov
er d
isto
rtio
n.
With
this
brid
ge
des
ign,
the
tran
sist
ors
shar
e
the
sam
e vo
ltag
e, c
urre
nt a
nd lo
ad s
o on
ly o
ne
pow
er s
upp
ly is
req
uire
d p
er c
hann
el. T
his
resu
lts in
an
effi c
ient
use
of b
oth
pow
er s
upp
ly
circ
uitr
y an
d c
hass
is s
pac
e. R
apid
, uni
form
heat
dis
sip
atio
n is
pro
mot
ed b
y ou
r tr
ansi
stor
mou
ntin
g a
nd h
eat d
iffus
er d
esig
ns. S
mal
ler,
mor
e co
mp
act c
hass
is c
an b
e us
ed w
hich
pro
vid
e a
very
hig
h ou
tput
pow
er to
siz
e an
d
wei
ght
rat
io.
Mac
ro-T
ech
Soni
c Pu
rity
Mac
ro-T
echn
olog
y —
a c
ombi
natio
n of
tech
nolo
gica
l adv
ance
s th
at e
nhan
ce
the
qual
ity o
f liv
e an
d re
cord
ed s
ound
, and
Cro
wn’
s co
mm
itmen
t to
prod
uct
exce
llenc
e in
rea
chin
g in
nova
tive
leve
ls o
f per
form
ance
and
rel
iabi
lity.
Sho
wn
on th
e ne
xt th
ree
pag
es is
a re
pro
duc
tion
of th
e or
igin
al M
acro
-Tec
h b
roch
ure.
21
OD
EP
™ (
Out
put D
evic
e E
mul
ator
Pro
tect
ion)
OD
EP,
Cro
wn’
s so
phi
stic
ated
pro
tect
ion
circ
uitr
y, is
a r
adic
al
dep
artu
re fr
om o
ther
am
plifi
er
pro
tect
ion
met
hod
s.
Cro
wn
dev
elop
ed O
DE
P to
sol
ve tw
o lo
ng-s
tand
ing
pro
ble
ms
in
amp
lifi e
r d
esig
n: to
pre
vent
am
plifi
er
shut
dow
n d
urin
g d
eman
din
g
oper
atio
n, a
nd to
incr
ease
the
effi c
ienc
y of
out
put
circ
uitr
y. T
o d
o
this
, Cro
wn
initi
ated
a p
rog
ram
whi
ch te
sts
ever
y ou
tput
tran
sist
or
to d
eter
min
e its
SO
A (
safe
op
erat
ing
are
a). O
DE
P c
ircui
try
insi
de
the
amp
lifi e
r th
en s
imul
ates
the
oper
atio
n of
the
outp
ut tr
ansi
stor
s
and
com
par
es it
to th
eir
SO
A. I
n th
e un
likel
y ev
ent t
hat m
ore
pow
er is
req
uire
d th
an th
e tr
ansi
stor
s ar
e ca
pab
le o
f del
iver
ing
und
er c
urre
nt c
ond
ition
s, O
DE
P im
med
iate
ly li
mits
thei
r d
rive
leve
l unt
il it
falls
with
in th
eir
SO
A. T
his
limiti
ng is
pro
por
tiona
l and
is k
ept t
o an
ab
solu
te m
inim
um. T
his
leve
l of p
rote
ctio
n en
able
s
Cro
wn
to in
crea
se o
utp
ut e
ffi ci
ency
whi
le a
t the
sam
e tim
e g
reat
ly
incr
easi
ng a
mp
lifi e
r re
liab
ility
. You
get
max
imum
pow
er w
ith
max
imum
pro
tect
ion.
Unl
ike
othe
r am
plifi
er
pro
tect
ion
sche
mes
that
shu
t dow
n th
e
amp
lifi e
r, C
row
n’s
OD
EP
mak
es c
erta
in th
e sh
ow g
oes
on.
IOC
® (
Inpu
t Out
put C
ompa
rato
r)Th
e IO
C is
a s
ophi
stic
ated
bui
lt-in
dis
tort
ion
met
er th
at
com
par
es th
e w
ave-
form
of t
he in
put
sig
nal t
o th
e w
avef
orm
of
the
outp
ut s
igna
l. In
the
rare
inst
ance
that
it d
etec
ts a
var
iatio
n
of 0
.05
per
cent
or
mor
e, it
fl as
hes
the
IOC
ind
icat
or o
f the
offe
ndin
g c
hann
el.
The
IOC
ind
icat
ors
help
you
trou
ble
shoo
t the
sou
rce
of d
isto
rtio
n
by
show
ing
you
whe
re it
’s n
ot —
you
r C
row
n am
plifi
er.
P.I.P
. Com
patib
ility
All
Mac
ro-T
echs
are
P.I.
P® (
Pro
gra
mm
able
Inp
ut
Pro
cess
or)
com
pat
ible
. The
se c
ircui
t car
d m
odul
es
plu
g in
to a
P.I.
P. c
onne
ctor
on
the
rear
pan
el o
f the
amp
lifi e
r. C
row
n’s
P.I.P
. mod
ules
ena
ble
you
to ta
ilor
each
am
plifi
er
to s
pec
ifi c
app
licat
ions
as
wel
l as
plu
g
into
futu
re te
chno
log
y as
it’s
dev
elop
ed. I
nsta
llatio
n
of a
n IQ
-P.I.
P. p
erm
its e
ach
Mac
ro-T
ech
to in
terf
ace
with
our
inno
vativ
e IQ
Sys
tem
™ fo
r co
mp
lete
am
plifi
er
mon
itorin
g a
nd c
ontro
l. S
ome
curr
ent P
.I.P.
mod
ules
incl
ude
a so
phi
stic
ated
pro
gra
mm
able
cro
ssov
er
and
eq
ualiz
er, r
emot
able
mic
/line
prio
rity
mix
ers
and
calib
rate
d s
ensi
ng m
odul
es.
Am
plifi
er S
tatu
s A
t A G
lanc
eTh
e M
acro
-Tec
h S
erie
s fro
nt p
anel
giv
es y
ou v
ital
oper
atin
g in
form
atio
n w
ith a
min
imum
of e
ffort
. Tw
o
dua
l-fun
ctio
n IO
C/S
igna
l Pre
senc
e in
dic
ator
s m
onito
r
the
tran
sfer
func
tion
of e
ach
chan
nel.
Gre
en in
dic
ator
light
s ill
umin
ate
to s
how
sig
nal p
rese
nce
and
fl as
h
brig
htly
if d
isto
rtio
n eq
uals
or
exce
eds
0.05
per
cent
.
An
amb
er E
nab
le in
dic
ator
, pow
ered
by
a sm
all,
sep
arat
e p
ower
sup
ply
, ver
ifi es
op
erat
ion
of th
e
amp
lifi e
r’s lo
w s
igna
l circ
uits
, DC
pro
tect
ion
and
onb
oard
dig
ital c
omp
uter
.
A p
air
of a
mb
er O
DE
P in
dic
ator
s sh
ow th
e re
serv
e
ener
gy
stat
us a
nd in
dic
ate
whe
n un
favo
rab
le
oper
atin
g c
ond
ition
s ar
e se
nsed
and
lim
iting
is
beg
inni
ng to
take
pla
ce.
22
Lege
ndar
yW
hile
man
y m
anuf
actu
rers
hav
e co
me
and
gon
e,
Cro
wn
has
cont
inue
d to
pro
sper
. For
ove
r 40
yea
rs,
the
owne
rshi
p o
f our
com
pan
y ha
s re
mai
ned
unch
ang
ed —
a c
laim
we
alon
e ca
n m
ake.
And
thro
ugh
thes
e m
any
year
s, o
ur c
omm
itmen
t to
the
ind
ustr
y an
d c
usto
mer
s ha
s st
ayed
true
. Our
trad
ition
for
uneq
uale
d e
xcel
lenc
e ha
s b
een
refl e
cted
tim
e an
d a
gai
n in
acc
olad
es fr
om o
ur
pee
rs, i
nclu
din
g th
e re
cent
ran
king
by
Pro
Sou
nd
New
s as
num
ber
one
in to
urin
g s
ound
. Fur
ther
,
of th
e to
p te
n to
urin
g g
roup
s at
any
giv
en ti
me,
a
maj
ority
are
usi
ng C
row
n eq
uip
men
t.
Our
tech
nica
l sup
por
t sta
ff is
une
qua
led
for
frie
ndly
, kno
wle
dg
eab
le s
ervi
ce a
nd a
re w
ithin
a
pho
ne c
all’s
rea
ch. T
hey’
re w
ell v
erse
d w
ith a
ll
asp
ects
of C
row
n am
plifi
ers
and
offe
r a
leve
l of
sup
por
t uns
urp
asse
d in
the
ind
ustr
y.
To e
nsur
e w
e ac
hiev
e ou
r st
and
ard
for
pro
vid
ing
the
very
bes
t pro
duc
t pos
sib
le, w
e m
anuf
actu
re
our
own
circ
uit b
oard
s, fo
rm o
ur o
wn
shee
t
met
al, a
nd m
achi
ne a
nd p
aint
our
ow
n p
arts
. It’s
a co
nsta
nt s
triv
ing
for
exce
llenc
e th
at re
fl ect
s
the
hig
h le
vel o
f prid
e ou
r em
plo
yees
hol
d. O
ur
asse
mb
lers
are
ski
lled
cra
ftsm
en w
ho h
ave
wor
ked
for
us fo
r m
any
year
s, a
nd w
e sa
y w
ithou
t
rese
rvat
ion
or d
oub
t tha
t our
eng
inee
rs a
re th
e
bes
t. It’
s no
won
der
that
our
am
plifi
ers
are
, too
.
23
Top
left
to r
ight
: Mac
ro R
efer
ence
, M
icro
-Tec
h, a
nd M
acro
-Tec
h br
ochu
res.
Rig
ht: M
acro
-Tec
h br
ochu
re a
nd a
C
row
n ne
wsl
ette
r ar
ticle
abo
ut th
e M
acro
-Tec
h 50
00V
Z.
We
hop
e yo
u’ve
enj
oyed
this
jour
ney
into
the
exci
ting
pas
t
of th
e C
row
n M
icro
-Tec
h an
d
Mac
ro-T
ech
Ser
ies
— a
mp
lifi e
rs
that
are
wor
ld re
now
ned
for
thei
r
tech
nica
l inn
ovat
ions
, rel
iab
ility
and
sup
erb
sou
nd.
TRAD
EMAR
KS N
OTIC
E: C
row
n, C
row
n Au
dio,
IQ, I
OC, I
Q Sy
stem
, Mac
ro-T
ech,
ODE
P, P
.I.P.
, and
VZ
are
regi
ster
ed tr
adem
arks
; Gro
unde
d Br
idge
, PIP
, and
PIP
2 ar
e tra
dem
arks
of C
row
n In
tern
atio
nal.
Syst
em A
rchi
tect
and
JBL
are
use
d fo
r inf
orm
atio
n on
ly a
nd a
re th
e pr
oper
ty o
f the
ir re
spec
tive
com
pani
es.
Crow
n Au
dio,
Inc.
rese
rves
the
right
to m
ake
chan
ges
in s
peci
ficat
ions
, sof
twar
e, o
r pro
duct
s w
ithou
t prio
r not
ice.
Cro
wn
Audi
o, In
c. a
lso
assu
mes
no
resp
onsi
bilit
y fo
r any
err
or in
type
or p
rint r
epro
duct
ion
of th
e fe
atur
es o
r spe
cific
atio
ns in
this
lite
ratu
re. T
he in
form
atio
n pr
ovid
ed h
ere
was
dee
med
acc
urat
e as
of t
he p
ublic
atio
n da
te. H
owev
er, u
pdat
es to
this
info
rmat
ion
may
hav
e oc
curr
ed. F
or th
e la
test
in p
rodu
ct in
form
atio
n, p
leas
e vi
sit t
he C
row
n w
ebsi
te a
t ww
w.c
row
naud
io.c
om.
Som
e m
odel
s m
ay b
e ex
porte
d un
der t
he n
ame
Amcr
on.
©20
08 b
y C
row
n A
udio
®, I
nc.,
1718
W. M
isha
wak
a R
d., E
lkha
rt, I
ndia
na 4
6517
-943
9 U
.S.A
. Tel
epho
ne: 5
74-2
94-8
000
1406
23-1
01/0
8
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