Marantz 2245 manual 

Model 2245
Stereoohonic
Becdiver

rrrä-roArnt-" Model 2245
Stereoohonic
Recriiver
MARANTZ CO,, INC..P.O. BOX 99.SUN VALLEY CALIFORN IA.91352
A WHOLLY-OWNED SUBSIDIARY OF SUPERSCOPE INC., SUN VALLEY CALIFORNIA 91352

Elt,seE.üaürgüEr
We sound betler.
WARRANTY
Maranrz Company, lnc-, prosdly warrants your Maränlz prodüct io be free o{ manulacturins defects
in material and workmanship as lollows:
From date oI Purchase
Erectroniccomponenrsa'dReceive's iääH: :I:i:
+Channd Remote Control
Pluq-in Matrix Decodeß
Speakeß and Cabinets
PARTS . 3 veaß
LABOR - 3 years
PARTS ' 3 years
LABOR - 3 years
PARTS - 3 yeals
LABOR - 3 yeaß
PARTS - 5 years
LABOB - 5 y€aß
TO VALIDATE YOUB WARRANTY, YOU MUST FILL OUT AND IVIAIL THE WABRANTY BEG'
ISTRATION CARD TO MAFANTZ COMPANY, INC., P. O. BOX 99. SUN VALLEY, CALIFORNIA
91352. WITHIN TEN DAYS FOLLOWING THE DATE OF PURCHASE.
For Wanänty repair, send this Ploduct to Maran? Companv, lnc., 8'150 Vineland Avenue, Sun Vallev,
California 91?52, or to an AUTHORIZED Mamnlz Service Station. All shippinq charges must be prepaid,
lvläEntz will pay return shipping charges ro anv d6iqnated Point within the United States.
This Wärranty is void if the terial nümber has been altered or removed; if the Product is mddilied or
repair€d in any manner which Marantz believes mav aff€ci the reliabilitv of the product; iI the product
k not op€räted in aeoldance with the insttuction manual.
l/brantz shall have no liability whätsoever lor consequentiäl damages. The sole resPonsibilitv o{ Marantz
Comp.ny, Inc,, under this Wairanty shall be limited to the tePair oI the product, or teplacement thereoi
in rhe sole diicrerion ot [4arantz company, lnc.
EXCEPT TO THE EXTENT THAT APPLICABLE LAW PBECLUDES A DISCLAIMER OF WARRANTY,
THERE IS NO III/IPLIED WARRANTY OF IIIERCHANTABILITY OR FITNESS WITH RESPECT TO
THIS PRODUCT, NOR ARE THEBE ANY OTHEB WARBANTIES WHICH EXTENT BEYOND
THE PROVISIONS OF THIS WABRANTY.
81 50 Vineland. ,$tetue. Sun Valle./, Califltnio 91352
REGISTRATION FOR MARANTZ 3.YEAR GOLDEN
WABRANTY
lvlodel: Marantz IVlodel 2245
Serlal No-
Purchased From {Name)
,nitffi piiE#\$fl fd'$i $ifi fi$iFiII >
Date Wardnty Replv Cdrd l,4ailed
The above information becomes yo!r permanent re.ord ol
a valuable purchase. lt shouLd be promptly filied in at the
same time that vou fill ln and mai th€ waiianty reg stratlon
reply cärd to t\,4arantz. Thls information provides a !alüabie
lnsuränce record and must also be referred 1o should Vou
häve any correspondence wirh Maranlz.

TABLE OF CONTENTS
Preparation for Use
Rear Panel Connections
Phono
Tape ln
Tape Out
Auxiliary
Ouadradial
l\4ain ln and Pre Out
Loundspeaker Systems
Anlenna Attenuator
Power Connections
Connection to AC Outlet
Convenience Outlet
Simplif ied Operating Procedure
Tuning lvleters
Tuning
l\4ono Switch
Tape lMonitor Switch
Loudness Switch
Low Filter Switch
Hi Filter Switch
l\4uting Switch and Level Control
lVIain Controls and Switches
Selector Switch
Balance Control
Volume Control
Bass l\4id and Treble Controls
lVIain-Spkr Remote Switch
Front PanelJacks
Dubbing Out
Dubbing ln
Stereophones
Some Suggestion on Using Tape Recorders
with Your Model 2245
Recording and Playback
Becording
Playback
lMaa<ing Two Recordings Sirnultaneously
Becording a Long'Duration Program
Copying and Editing
Convertinq Your Stereo System to
4 channel
Technical Description
General
Functional Description
Front End
lF Stages
Lim iter
FM Stereo Demoduläror
2
2
2
2
2
3
3
3
3
4
5
5
5
5
6
6
6
6
6
6
6
6
1
7
7
7
7
7
8
8
8
8
I
8
8
I
I
11
11
11
11
12
12
12
l\,4uting Circuit
Selector Switch
Tape Signals
Tape l\4onitor Switch
Phqno Signals
I\4ono Functions
Control Circuits
Balance Control
Volume Control
Tone Ampli{ier
Hi-Lirw Filter
Output Stage and Protective Circuits
Technical Specificataons
Typical Per{ormance Curve
Service Note
12
12
12
13
13
13
14
14
15
15
15
16
17
19
LIST OF ILTUSTRATIONS
1. Rear Panel Connection Facilities and
2.
3.
4.
5.
6.
7.
8.
10.
11.
12.
13.
14.
15.
16.
17.
Adiustments 2
Loudspeaker System Connectlons 3
Fl\4/A[\4 Antenna Conneclion 4
AIVI Ferrite-rod Antenna 5
Front Panel Controls and Jacks 1
Stereophone Plug I
Arrangement oJ Two Tape Becorder I
Connection Diagram 10
Functional Block Diagram 1'l
PhonoEqualizationCharacteristics 13
Tone Control Characteristics 14
Low and High Filter Characteristics 14
FlVi Characteristics 17
Stereo Separation 17
Harmonic Di$ortion 18
Frequency Response '18
Päckinq lnstructions 1S

F{3HüWffiMM
For optimum performance and enjoyment from
Vour l\,4odel 2245 Sleteo Receiver, please srudy
these instructions carefLllly. lnstallation and opera
lion are not complicated, but its flexibility and
fpatu'es deserve yoL/ beLomlrg ldnrllal wlth ils
controls and connections.
This manual is divided into two parts The first
covers installation and operation in simple,
non-technical lanqllage. The second describes the
2245 in mote detail with technical specifications,
Junctional explanations, and special application
discl]ssions.
For quick identification of the controls and
connections, references to them are printed in
boldface type, exacrly as thev appear on the fronl
and rear panels o{ Your Receiver-
ffi ffi ru ffi ffi A{- mffi s#ft I rT'!f-}p$
Your lMarantz Model 2245 all solid state recelver
incorporates the advanced circuitry for which
l\4arantz is famous in the audio component
ind!rstry.
Unparalleled technology and innovation made possi
ble this combination of three superb component
sections on a single chassis: Tuner, Preamplifier,
and Power Amplifier. lnternal connections be-
tween these cornponent sections ensure optirnum
per{orrnance from each section, and retain the full
flexibility o{ separate components- The extra-
ordinary flexibility o{ your l\,4odel 2245 permits
the connection of: two srereo pairs of loudspeak'
ers; headphones; a lurntab e or record changer; an
additional luner (such as SW or LW) and ä TV
solrnd source. Record, pLayback, and copying
capabilities are included {or a lape playback deck
or two recorders.
AFTER UNPACKING
It is advisäble to save all original packing material
to prevent damage should you wish to transport or
ship the Receiver (refer to Figure lT for packing
instructionsl.
Please inspect your l\,4odel 2245 catelully Io( aoY
signs of darnage in transit. lt has undergone
stringenl quäliry conTrol inspection dnd rests ptiot
to packing, and left the {actory in perfect
operating condition.
lf the unit is damaged, notify the carrier without
delay.
Onlv the consignee may institute a claim with the
carrier for damage during shipment. However, the
l\4arantz Company will cooperate {ully in such an
Save the damdged carlon as evidence jor inspeclion
by the carrier.

C
PHONO
I he phono jdcks are intended lor use with
magnetrc phono cartridges requiring a standard
47,000-ohm resistive load. lf hum is heard when
playing records, it is usually evidence ol improper
grounding or shrelding ot the record prayer or its
connections. Try reversing the polarity oJ the
turntable's power plug. lf this is ineffective,
connect a separate ground wire from the tLrrntable
or record changer frame to the CHASSIS
GROUND binding posts of the lModet 2245. tf the
tone arm is mounted on a wood panel or is
otherwise insulated from the turntable frame,
connect the lone arm mounting base to the
grounding wire with d short wrrp. ll thc t!1,o pars
o{ signal wires in the arm have a single overall
shield, trv grounding lhe shield instedd ol the drrr
Figure l. ßear Panel C0nnectiofl FacililiesEnd Ad,ustmeds
itself. Keep the two PHONO connecting cables and
the grounding wires close togelher to minimire
"ground loops."
TAPE IN
The pair o{ TAPE lN jacks serve two purposes:
1. Wilh the selector slvitch irJ'TAPE'bosition,
signals can be played from a tape recorder
set for playback mode of operation. This
permits playinq the tape sou rce stere
ophonically or monophonically as indicat-
ed by position of MONO pushswitch.
2. With the selector switch in any other
position, and while your tape recorder is
recording, you can monitor the resulting
tape quality bv depressing the TAPE
MONITOB pushswitch. This presumes that
your recorder is equipped with separate
record and playback heads and separate
record and playback electronics.
TAPE OUT
Connectinq these iacks to the line or "tadio"
inputs of a tape recorder permits recording from
the program source indicated by the selector
switch. The signals available at this pair of jacks are
not affected by the balance. volume, treble, mid,
bass, LOW FILTER, Hi FILTER. or LOUDNESS
and lvlONO pushswitches on the front panel.
PREPARATION FOR USE
REAR PANEL CONN ECTIONS
All signal connections to the l\4odel 2245, wilh the
exception of the Fl\4 antenna and loudspeakers,
$ould be made with shielded audio cables. Figure
1 shows the location of input and output jacks on
the rear panel. These jacks are for "permanent"
connections. Front panel jacks and their use will be
discussed ldtpr. The rear panel siqndl connections
are arranged in slereo pairs. To avoid confusion,
connect one cable at a time between the 2245 and
the other components of your system. ln this way,
you wili avoid cros+connecting channels or con
fusinq siqnal sources with destinations.
c

AUXILIARY
High level AUX input iacks are for miscellaneous
sources such as extra tape players with self
contained playback preampl if iers, phono cartridges
wilh RIAA equalized high-level output, additional
t!ners and/or receivers, TV sound outputs, and
other external components.
OUADBADIAL
ln anticipation of rhe coming o{ 4 channel stereo
broadcastinq, your l\lodel 2245 is equipped with an
ourpur OUADRADIAL jack. The signal available at
this jack is the unequalized, buffered output of the
Fl\,4 discriminator. lts level, frequency response
characteristic and output impedance are ideal to
drive anv 4 channel adaptor. This jack can also be
used as a simple white noise generator for {re
quency response check of loudspeakers or ampli
fiers, with the lvlodel 2245 in FI\4 mode and tuned
off from any FM signal.
MAIN lN and PRE OUT
Connections Jrom the l!4odel 2245 preamplifier
outputs to the power amplifier inputs are per
+ormed externally. Special jumper plugs normally
interconnect these lvlAlN lN and PRE OUT iacks
Removing these two special jumper plugs allows
you 10 use vour 2245 as an independent basic
stereo amplifier and/or an independent stereo
control center, Be sure to replace the iumper plugs
between the MAIN lN and PRE OUT jacks for
normal operalion.
3
Figure 2. Loudsteaker System Connections
LOUDSPEAKEB SYSTEMS
The SPEAKEB SYSTEIMS terminals on the rear
panel will accommodate Iwo stereo paars of
loudspeaker systems of rated impedance between 4
ohms and 16 ohms. When using only one stereo
pair o{ loudspeakers, connect them to the MAIN
terminals. The REII4OTE {erminals are for a second
stereo pair of loudspeakers.
Selection of loudspeaker systems is made wilh the
lvlAlN-SPKR-REMOTE pushswitches on lhe front
panel.
Use caution when connecting your lvlodel 2245 to
a loudspeaker with bualt in power supply such as
an electro-static loudspeaker, Tl,e "common"
conneclion terminal of such a speaker may be
capacitivelv qrounded through its power supply.
Vlake sure the GROUND terminals of the Model
2245 are connected to the "common" terminals of
such loudspeaker system.
Ordinarv #18 qauge, 2 conduclor lamp cord
("zipcord"i may be used for normal distances (to
about 25 Jeet) belween your 2245 Receiver and
your loudspeakers. For longer lengths, +16 gauge,
or heavier wire should be used to ensure optimum
speaker performance.
When connecting a slereo pair of loudspeakers, it is
important to ensure correct relative phasinq
(polarity). When usinq identical loudspeakers,
simply code one wire of each pair at both ends
with a knot, tape. etc.
J

C
(Note: Close inspection of ständard zipcord will
'pvaal \orp lorr o'codinq o'1 lhp r1'ulatron,4,q,,
rioqF o' g'oovp on ono pouo. onp o ll'F wrrp" näy
be "silver" while the other is bare copper.) Coded
wires help insure identical connections for each
channel,
For each channe. the coded wire can be connecred
between the "commoi" termjnal of your
loudspeaker and the GROUND terminal of the
amplifier channel. The remaining uncoded wire is
then connected between the remaininq Loudspeaker
and amplifier lerminals. This insures correct
polarity or phasing o{ identical loudspeakers.
l{ there is any doubt about phasing o{ loudspeaker
pairs, or if they are not identical loudspeakers, a
simple listeninq test can verify correct phasing.
With program signals fed to both channels, and
with the MONO pushswitch depressed, the sound
should appear to originale at a point midway
between the loudspeakers, with the balance control
centered. As the balance contro is turned away
from the center position, the sound source shou d
appear to move toward one of the Loudspeakers.
Room acoustics can somelimes make this test
ambiquous or confusing. lf so, lemporari y rnove
the loudspeakers as c ose toqether as possible. Then
set the controls for balanced IMONO operätion and
listen to program material with strong bass pass
ages. Reverse the wires to one of the loudspeakers
and listen to the same passage again- lf there is
.ofic"obly less b"\s w l I' c 'Fvp 'ad , orn"cr:on.
change the connections back to the original ar
ranqement. lf there is noticeably more bass, leave
the wires connected in reverse,
These phasinq procedures should be used with each
stereo pair of Loudspeakers, whether IMAIN or
REMOTE. lf both pairs of loudspeakers are used in
the sanre listening area, ensLrre that the [4AlN
peir is also "in phase" with the REMOTE pair.
CAUTION:
NEVER DIRECTLY CONNECT THE LOUD
SPEAKER TERIV]INALS OF ONE CHANNEL
IN PARALLEL WITH THOSE OF ANY
OTHER. ANY RESULTING DAMAGE IS
NOT COVER ED UNDE R WARRANTY.
FM ANTENNA
The best F [/] reception is obtained with a
Log-Periodic type antenna, moLnted on a qood
quality rolor system. For fringe areäs, I\4arantz
recommends a Log Periodic antenna with six or
more elements designed expresslV Jor FM
reception. For minimum local noise and multipath
picl<Lrp by the lead in wires, Lrse a balanced änd
shielded 300ohm cable. (An unshielded lead-in
wire can act as än omnidirectional antenna, and
can cancel the directional benefits of your
ä1'pr1a.) Lolv los.300.ol_Tl \' eld"d cdb'p ' or\,sls
of two inner conductors plus an ouler shield and
insulating jacket. This type of shielded cabe
effectively prevents the lead-in from contributifg
multipath distortion.
For rural areas, it is recommended that a loca
dealer be consulted about antenna installation and
lightning arrestor protection- I\,4aster antenna
system are not recommefded {or use with your
Model 2245; such systems are usually designed
expressly {or television reception and frectuently
suppress FM siqnals before distribution. ln
addition, rnaster antenna systems often severely
limit good qLrality FIVI reception.
Where ouldoor antennas are prohibited or
inconvenient, use a simple form of 300-ohm, TV
"rabbit ear" antenna or the simple ribbon type
{olded dipole anterrna supplied with the lvlodel
2245. Aarh are practical änd will qive satisfactory
results in primarv siqnal areas. Your [,4odel 2245
Receiver will accept either a 75 ohm or 300 ohm
antenna. (See diagram Figure 3.) The 300ohm
inrenna cable should be connecled to the two
terminals marked FIM on the ANTENNA terminal.
When using 75 ohm coaxial antenna cable, connect
its sh;eld to the "G" (GROUND) terminal, and its
inner or center conductor to either of the FM
üü
Fiqure 3. Fl',4/A[4 Antenna Connection

Figure 4. AM Ferrite-rod Antenna
ANTENNA ATTENUATOR
The ANTENNA ATTENUATOR can be switched
into or out of the anlenna circuit. Use the
ANTENNA ATTENUATOR switch in the "lN"
position only when overloading is apparent from
reception of one station at several points of the
dial and is affecting reception of a desired station.
Overloading may also cause severe distortion which
will not disappear with proper antenna orientation.
(NOIE: With thE ANTENNA ATTENUATOR
switch "1N", the FI\4 sensitivity and the number of
stations that can be received are greatly reduced.)
AM ANTENNA
Your Receiver is equipped with an Al\4 {errit+rod
antenna,
BEFORE USING THE I\4ODEL 2245, PULL THE
ANTENNA OUT AS SHOWN IN F IGU RE 4,
The {erriterod antenna will give you satistactory
results Io primary signal areas. However, an
outdoor dntennd \rvill piovide better receptiol.
Two single wires are required to make an AlVl
outdoor antenna, First, connect one end of a single
wire to the AlVl antenna terminal on the rear panel,
and the other end at a very high posilion oLltdoors
(the higher the better), or swing it from the
window of your room. Next, connecr the other
single wire between the "G" (GROUND) terminal
of your Model 2245 and an authenticäted earth
ground (such as a metal waterpipe).
5
POWER CONN ECTIONS
The i!4odel 2245 is equipped with a universal
power lransformer to permit operation at any
standard AC line voltage and at frequencies oJ 50
Hz to 60 Hz. For operation at line voltaqes other
than indacaled on the rear panel nameplate, ha/e a
qualified technician perJorm the simpie wiring
changes necessarY.
CONNECTION TO AC OUTLET
With the front panel power pushswitch "oot," plug
the line cord into an electrical outlet supplyinq the
proper voltaqe. CAUTION: DO NOT PLUG YOUR
MODEL 2245 INTO A DC OUTLET. SINCE
SEBIOUS DAIVIAGE WILL OCCUR.
CONVENIENCE OUTLET
One UNSWITCHED and one SWITCHED AC
oUTLET are provided on the rear panel for
powering associated components of your system
(tape recorder, record player, etc.),
SIMPLIFIED OPERATING PROCEDURE
When operating the fi,4odel 2245 Stereo Receiver
for the first time. follow these sirnple directions-
Later, full advantage can be laken of its versatility
with the remaining cgntrols and pushswitches.
Slep L Connecr r1p F l\,4 dltenrd lo rhe dpproori
ate terminals on the rear Panel.
Step 2. Connect the speakers to the MAIN speaker
terminals.
Step 3. Check that all pushswitches are in the
"out" position. Pushswitches in lhe "in" position
should be depressed for releasing to the "out"
position.
Step 4. Turn the volume control all the way to the
le{t (counter clockwisei and set the balance control
in mid posirion (poinler to dot ät 12 o'clocki
Step 5. Rotate treble. mid, and bass controls to
the i2 o'clock posilion {each pair of pointers to
dot).
Step 6. Set N4AIN Speäker pushswitch "in," and
REMOTE "o!t" (assuminq your loudspeakers are
connected to the NIAIN amplifier terminals)
Step 7. Turn on system power by depressing the
power switch.
Step 8. Select the desired program source by
serting the selector switch to the appropriate
J
)