Model 2245 Stereoohonic Becdiver
Model 2245 rrrä-roArnt-" Stereoohonic Recriiver MARANTZ CO,, INC..P.O. BOX 99.SUN VALLEY CALIFORN IA.91352 A WHOLLY-OWNED SUBSIDIARY OF SUPERSCOPE INC.
Elt,seE.üaürgüEr We sound betler. WARRANTY Maranrz Company, lnc-, prosdly warrants your Maränlz prodüct in material and workmanship as lollows: io be free o{ manulacturins defects From date oI Purchase Erectroniccomponenrsa'dReceive's iääH: :I:i: .
l\,4uting TABLE OF CONTENTS Circuit 12 Selector Switch Preparation for Use Rear Panel Connections Phono Tape ln Tape Out Auxiliary Ouadradial l\4ain ln and Pre Out Loundspeaker Systems 2 2 2 2 2 3 3 3 3 4 Anlenna Attenuator 5 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 S
A{- mffi s#ft rT'!f-}p$ F{3HüWffiMM ffi ffi ru ffi ffi For optimum performance and enjoyment from Vour l\,4odel 2245 Sleteo Receiver, please srudy Your lMarantz Model 2245 all solid state recelver incorporates the advanced circuitry for which l\4arantz is famous in the audio component lion are not complicated, but its flexibility ind!rstry.
Figure l. ßear Panel C0nnectiofl FacililiesEnd Ad,ustmeds C PREPARATION FOR USE REAR PANEL CONN ECTIONS All signal connections to the l\4odel 2245, wilh the c 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.
Figure 2. Loudsteaker System Connections AUXILIARY LOUDSPEAKEB SYSTEMS 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. 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.
(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.
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.
position. lJ Flvl or A[4 is selected, rotale the Gvro-Touch TUNING knob until the desired station is tuned. Adjust the volume control for comJortable I istening volume. The tuner section of the l\4odel 2245 is ectuipped wilh electronically triqqered circuits which automaticallv mute interstation noise and automatical ly swilch to lhe proper mode of operation for stereo and monophonic FI\4 broadcasts. ln addition, the STEREO indicator liqht äutomatica'ly indicates a stereo broadtast.
Figure MAgru fflruTR$t$ SELECTOB SWITCH The selector switch selects the program source for listening or recording. lf a tape recorder's playback output has been connected to the TAPE lN iacks on the rear panel, you can select tape listeninq by selector switch to the "TAPE" position {with rhe TAPE l\4oNlToB pushswitch ;n the C0ntrolsand Jacks unbalanced room acor-lstics or for any other tonal imbalance in proqram material.
equally simple arrangement using the front panel facililies involves connecting the line inputs to the dubbing OUT jack and the playback outputs to the dubbing lN jack. RECORDING COMMON RIGHT CHANNEL Fiqur€ 6. Stereophone nug DUBBING IN This jack has a built in switch which automatically disconnects the rear panel TAPE lN jacks when you insert a standard 3 conductor phone plug. lt is intended to receive the playback outputs of an external tape recorder.
then prepare the external recorder to beqin record ing before the main recorder is about 10 run out of tape. As soon as the external recorder is started, arnple time will be available to reload the mäin recorder in preparation for further recording. This process can be repeated indefinitely with both machines. At anv time during the recording ses sion, the recording can be monilored by depressing the TAPE I!4ONITOR pushswirch. To Copy from the external recorder to the main REN4E[.
o o D u u u o c) - c :(to :: Figure 8.
J Figure 9. Functional Block Diagram TECHNIEAL FUNCTIONAL DESCRIPTION DFSCRIPTION GENERAL FRONT END diagram of the [/]odei 2245 Receiver showing the main functional elements and input and output signal routing. Each Afl and Fß,4 front end has its own lF stages. For clarily, onlv the leJt audio channel is shown; the right audio channel is identical. The |\4ONO switch is common to both chännels. All audio controls are ganged, or con(entrically clulched, to lhplr coJnLelporls il the righl channel.
generated by a local oscillator. This mixer converts the carrier frequency to the 10.71\,4H2 intermediate frequency. Care{ul attention to its thermal and electrical characleristics has minimized drift, thus obviatinq the necessity for AFC. The 107[,4H2 converted siqnal is lhen fed to a phaselinear ceramic lF Jilter, followed by an lC limiter. lt is then, in t.rn, processed lhrouqh dn FIVI drqcrim;na_ 1or.
selectively to the desired source. TAPE SIGNALS With the exception o{ tape input, all high leve inputs are {ed directly to the s€lector switch. Tape input is routed through the front panel dubbing lN jack to a section of the TAPE MONIToR switch. The dubbinq lN jack is a three conductor stereo jack which has two built_in switches, one for each channel. Normally, these switches are closed, a!lowing the tape input signals from the TAPE lN jack on the rear panel to be fed to the TAPE IMONITOR switch.
conlrol at maximum, the over all voltage gain from any h iqh level input to the loudspeaker terminals is approximately 40d8. BALANCE CONTROL The balance control is a wide range control which oermits atLenudtion ol each channel to cutotf The chanqe of attenuation in edch channel as the control is turned away lrom center has been designed to maintain total apparent loudness from both channels.
TONE AI\4PLIFIER The TONE A[,4PL|FlER's circuitry uses a con tinuouslv variable R-C {eedback type configura tion. Figure 11 shows the frequency response curves for maximum boost and cut {or each control. The signal from the TONE A[4PLl FIER feeds the hillow filter circuil when the Hi FILTER or the LOW FILTER pushswilch is depressed. H|-LOW FILTERS Fiqure 12 shows the {requency response curves resulting {rom use of the two filters. OUTPUT STAGE AND PROTECTIVE CIR.
TECHNICAT SPECIFICATIONS AUDIO CIRCUITS: Rated continuous (RI\4S) power outpul per channel, both channels operating . ;imultaneously, 20 Hz to 2O,OOO Hz (lHF) 45 Watts at 4 and 8 ohms 25 Watts at 16 ohms l35 Watts at 8 ohms .. . . Comparable Total l\4usic Power High'level hum and noise (ref. 4OW at I ohms) Phäno hum and noise . Dynamic range {phono input to tape recordinq output) ... . . '1 . l.t\4.Distortian(SIVIPTE),atratedpower.-......
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Figure 15. Harmonic Distonion Figure 16.
Please Pack the Receiver as lllustrated. CAUTION Please DO NOT ship your receiver mounted accessory walnut cabinet. in its lnsure receiver for full value: Make sure that your correct return address is on shipping lable. Ship via a reputable carrier.(Do NOT UsE PARCEL POST)Be sure to obtain receipt from cafiier, SERVICE NOTES REPAIRS Only the most competent and qualified service technicians should be allowed to service the Marantz Model 2245 Receiver.
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The Sound of N4arantz the compelling warmth o{ a Stradivarius. It is a dancing flute, a haughty bassoon and the plaintlve call of a one French horn. The Sound of l\,4aranlz is the sound of beauty, and fularantz equipment is designed to bring you is the subtle ioy of its delight.
