~ R Model 4270 Stereo 2 +Quadradial 4 Receiver MARANTZ CO., INC.·P.O. BOX 99·SUN VALLEY, CALIFORNIA·91352 A WHOLLY ·OWNED SUBSIDIARY OF SUPERSCOPE INC.
WAR A All parts of MARAN TZ product s ar e f ully guaranteed fo r a pe riod of THREE YEAR S from date of purchase, ex cept for tubes wh ich are gua ranteed for NINETY DAYS fr o m date of purchase, and ex cept for speaker p roducts. Speaker product s are guarant eed .
• • • TABLE OF CONTENTS Connecting the 4270 Source Devices Remote Speakers Speaker Phasing Speaker Placement Front Panel Features Mode Switch Dimension SQ Decoder Balance Controls Selector Switch Bass, Mid and Treble Controls Monitor Switch for Tape 1!Tape 2 Monitor Switch for Tape/Source Main and Remote Spkr Switches Power Switch Front and Rear Phones Jacks Loudness Hi Filter Switch Tuning Meter Tuning FM Muting Switch Volume Dolby Switch Record Level (L) (R) Play Cal.
GENERAL DESCRIPTION FOREWORD Your Marantz Model 4270 is a high-quality Stereo 2 + Quadradial 4 Receiver developed by Marantz, a name famous for quality in the audio com ponent industry. The Model 4270 incorporates Marantz' exclusive Vari-Matrix circuit which sim ulates 4-channel sound from normal 2-channel stereo programs, and is capable of reproducing 4-channel sound from any matrix-encoded source.
Figure 1. CONNECTING THE 4270 The 4270 can be used as a stereo or 4-channel Receiver. When using the 4270 as a stereo unit, the POWER MODE Switch on the rear panel should be placed in the 70Wx2 mode. The instructions contained in this manual are to be followed for both stereo or 4-channel operation; however, for stereo operation, the front channels alone will apply. 1. Using a balanced and shielded 300 Ohm cable, connect an FM antenna to the 4270 as shown in Figure 11. 2. Using No.
REAR SPEAKER Sy STEM R{PEAT WIRING AS FOR FRONT sPEA KER SYSTEM LEFT Figure 2. Loudspeaker System Connections 5. Using shielded audio cables with phono plugs, connect a discrete 4-channel tape recorder to the 4270 as follows: RIGHT-REAR INPUT or LINE IN DISCRETE 4-CHANNEL TAPE RECORDER 6. Pull the AM ferrite-rod antenna out as shown in Figure 12.
11. If phono is selected, put on a stereo record. If FM is selected, tune to a stereo broadcast. 12. Increase the VOLUME control to a comfort able listening level. 4-channel Discrete 4-channel playback devices (0-8 cartridge player, 4-channel reel-to -reel player, CD-4 discrete disc demodulator, etc.) may be connected to the CD-4/AUX, TAPE MONITOR 1 or TAPE MONI TOR 2 input jacks .
SPEAKER PHASING To assure the best 4-channel or Stereo separation and frequency response, the following tests will verify that all four speakers are correctly phased. 1. After the speakers are connected to the 4270, place all four speakers in the center of the room. 2. Set MODE Switch at MONO. Play a record (or radio or tape) with strong bass tones, at a low volume level. Center the FRONT L-R and REAR L-R BALANCE controls. Set FRONT-REAR BALANCE control at extreme FRONT position. 3.
LF RF LF RF RF RR LR LF RR RF RF RF RR LR LF RF RR LR LF RF LR RR RR Figure 4.
FRONT PANEL FE lURES rear channel signals are varied by the DIMENSION control. Speakers are driven as shown in Figure 8. LEFT FRONT SPEAKER 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. ....................... " ..... " ,""" .,.
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or to monitor the tape on a three-head recorder during recording, place the MONITOR (TAPE/ SOURCE) pushswitch in the "TAPE" (in) posi tion. During recording, the MODE Switch should be in the DISCRETE, VARI-MATRIX or SO DE CODER positions. This applies the source signal unchanged, directly to the tape outputs. ' LOUDNESS When listening at low levels, set this switch "in".
FM MUTING SWITCH PLAY CAL. (L) (R) When tuning to FM broadcasts with the FM MUT ING Switch in its "in" position, the muting circuit will eliminate inter-station noise. To prevent muting of very weak stations along with the noise, the muting function may be turned off by releasing the FM MUTING pushswitch to the "out" position. These knobs adjust the playback outputs from a tape deck to the proper Dolby level.
R ARPA E FEATURES PHONO JACKS These two jacks are intended for use with magnetic cartridges requiring a standard 47,000 Ohm resistive load. If a hum is heard when playing a record, try reversing the polarity of the turntable power plug. If this is ineffective, connect a separate ground wire from the turn table or record changer to the CHASSIS GROUI\ID binding post of the 4270. CD-4/AUX JACKS These jacks are for connection of any 4-channel high level equipment source.
antenna will provide better reception. Two single wires are required to make an AM outdoor antenna. First, connect one end of a single wire to the AM ANTENNA terminal on the rear panel, and the other end at a very high position outdoors. Next, connect the other single wire between the "G" terminal and an earth ground (such as a water pipe). (Refer to Figure 11.
Terminals work as shown in Figure 13. 1) Press terminal in 2) Insert speaker wire 3) Release terminal TAPE RECORDING Instructions for connecting a recorder and playing back a tape are given in "SOURCE DEVICES", page 4. CONNECTION TO AC OUTLET With the front panel POWER pushswitch "OUT", plug the line cord into an electrical outlet supply ing the proper voltage. CAUTION: DO NOT PLUG YOUR MODEL 4270 INTO A DC OUTLET, AS SERIOUS DAMAGE WI LL OCCUR.
BASIC DOLBY PROCESS The Dolby system increases the level of low-level, mid- and high-frequency signals during recording and reduces the level of these signals by an identical amount during playback. As a result, the playback signal is identical to the original source signal, but the level of background noise generated by the tape recorder is greatly reduced. A Dolbyized FM broadcast has already been subjected to the first phase of the no ise reduction process before it is transmitted.
Since the calibration is extremely stable and should not have to be repeated (except to period ically check it), we suggest that you mark the settings of your recorder's output level controls with a felt-tipped pen. Doing so will enable you to easily reset the controls if they are inadvertantly moved. PROCEDURE FOR RECORD CALIBRATION Before proceeding with the record calibration, be certain that the playback adjustments have been performed .
Mark the calibration positions on the recorder's record and playback level controls to avoid the necessity of re-calibrating after making a non Dolby recording. be obtained by putting the DOLBY Switch in the "DOLBY FM" position. The rear panel DOLBY FM PRESET LEVEL controls are fac tory-adjusted. Do not change the position of these controls. IMPORTANT: It will be necessary to re-calibrate the Dolby levels when a change in tape speed has been made or when a different brand or type of tape is used.
r-- - - - - - - - - - - , r- - - - - - - .--- - - - - - - - - - - - - - -- - l FM IF·STAGE ANTENNA BALUN FM DETECTOR FM LIMITER FERRITE ROD ANTENNA SQ DECODER SOCKET (SQA·1l ,r-'---'---, FRONT L EMlnER FOLLOWER O~--'---..., PHONO CD·4/ AUX TAPE MONITOR I IN MODE SWITCH TAPE MONITOR 2 IN L IN r-'--_..., I L•OUT ~ SELECTOR SWITCH REAR L R TAPE MONITOR I IN O ~ ~ ~ O CD·4/AUX ~ DOLBY ~ ~ i@- - METER L C1Rcurr ' . J.
TECHNICAL DESCRIPTION GENERAL Figure 14 is a block diagram of the model 4270 Stereo 2 + Quadradial 4 Receiver showing main functional elements and input and output signal routing. PHONO INPUT jacks are provided for the front pair of channels. FUNCTIONAL DESCRIPTION FRONT END FM antenna signals are applied through a balun transformer to the antenna coil which drives a field-effect transistor RF amplifier.
The Sound of Maran IS tne I t is C i:J 7 irnpellmq warmth nf riancmq 'lute nd ttl i;l (I Str idivariu 11ClUgllt:y bassoon plaintive call of Ion French horn . The Sound of Marantz is the sound of beautv , and Marantz equipment IS deslgneel to brrnq you tile subtle JOY of IL delight Wonderful adventures III sound awau you when you discover that the Sound of Marantz is the sound of music CIt ItS very best. sa is a DOLBY trademark of Columbia Br oadcast in g Sys tem . Inc.
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