Marantz 4270 - Marantz 4270 Power Amplifier; Marantz 4270 Audio Trouble Analysis

FRONT PANEL FE lURES
MODE SWITCH
MONO
When
the MODE Switch is in the MONO position,
all input signals are summed. Speakers are driven
as
shown in Figure 5.
Use the MONO position for A) phasing speakers
and B) playing a monaural source such as TV
audio, AM radio or monaural records through
all four channels.
2 CH
When
the MODE Switch is in the 2 CH position,
left-front and left-rear inputs are summed. Right-
front and right-rear inputs are summed. Speak-
ers are driven as
shown in Figure 6.
Use
the 2 CH position for playing regular stereo
records without synthesizing rear channels.
DISCRETE
When the MODE Switch is in the DISCRETE
position, each input signal goes to its respective
output channel. Speakers are driven as shown
in Figure 7.
Use
the DISCRETE position for A) playing dis-
crete 4-channel sources such as 0 -8 cartridges or
CD-4 records, and B) playing 2-channel stereo
programs through front speakers only .
VARI-MATRIX
When the MODE Switch is in the VARI-MATRIX
position, rear input signals are internally discon-
nected. Left-front and right-front inputs feed
left-front and right-front speakers, as in the DIS-
CRETE MODE. Rear channel signals are "syn-
thesized" or derived from the left-front and right-
front input signals. The characteristics of the
LEFT FRONT RIGHT FRONT
SPEAKER SPEAKER
<, ",~'
"
..... '"
'"
,
\ LF + RF+ "~(''''LF + RF + I
\ LR + RR '" -. LR + RR '
\ '
,
\ I
'
\ ' \ ,
,,' \I
I
"
\
/\
:\
I ,
, \
I LF + RF + ..... "'LF + RF +'
I LR + RR '> ~ LR + RR \
I ... ........ \
~,. ....................
... .....
," """
LEFT REAR RIGHT REAR
SPEAKER SPEAKER
,NPUT SI GNAL OESIGNA. TlONS ;
lFo<lEfT fRONT . Rf-RIOHT fRONT
LA-lEn REAR . RR-RIGHT REAR
Figure 5. Mono Mode Sound Dispersion
rear channel signals are varied by the DIMENSION
control. Speakers are driven as shown in Figure 8.
LEFT FRONT
SPEA
KER
,,"
....................... ". ,.
<, ,""" I
" LF + LR ..... " RF.+ RR I
, .,." <, I
\
, I
'
\ I \ ,I
, I \I
"
"
I
1\
,
I \ ,
I ,
I \
I ..... '" ,
I
,>" . \
, LF + LR ",'" ..... RF + RR \
'" "",'" ...................
.-
LEFT REAR RIGHT REAR
SPEAKER SPEAKER
INPUT SI GN A L D ESIQN A,n ON S :
IF -L EFT fRONT , RF - R IGH T FRONT
LA-LEFT R fA R. RR"RI GHT REAR
Figure 6. 2- channel Mode Sound Dispersion
,
I
I
. I
I
I
\ I
\I
1\
I ,
\
,
\
RR "
\
LEFT REAR RIGHT REAR
SPEAKER SPEAKER
LEFT FRONT RIGHT FRONT
SPEAKER SPEAKER
\
\
\
\
,
\
\
'
,,'
I'
I \
I
I
I
I LR
I
IHf"VT SIQNAl DESIGNATIOHS :
Lf-lEfT FRONT , AF-RIGHT FRONT
l R- l EFT REAR, Aft-RIGHT REAR
Figure 7. Discrete Mode Sound Dispersion
LEFT FRONT
SPEAKER
.. ","
'"
'"
\ '...... "'" I
\ LF .. ~(", RF I
\ '" ~/
\ I
, I
\ , \ I
, I \I
't 1\
" I
1\\
I \
,'DERIVED '" DERIVED\
I FROM LF ... ,>~ FROM LF \
I AN DR E"'''' ......... ANDRF \
"."/' <;
. ... .....
.-" ...
LEFT REAR RIGHT REAR
SPEAKER SPEAKER
INPlIT SIGNAL DESIGNATIOJlIS :
V-LEFT FRONT , RF-RIGHT fRONT
lA-lEfT AEAA , nA-HIGHT REAR
Figure 8. Vari·Matrix Mode Sound Dispersion
7