OPERATOR'S MANUAL
4-HEAD 3-MOTOR AUTOMATIC REVERSE SURROUND STEREO TAPE DECK
WARNING: To prevent fire or shock hazard, do not expose this appliance to rain or moisture.
ANUFACTURED & DISTRIBUTED BY AKAI ELECTRIC CO., LTD./AKAI TRADING CO., LTD./AKAI AMERICA LTD.
GX (GLASS & CRYSTAL FERRITE) HEAD
GX (GLASS & CRYSTAL FERRITE) HEAD Akai has equipped this model with its new and amazing Glass & Crystal Ferrite Recording and Playback Heads to bring you unequalled open rel high fidelity sound. With the Glass & Crystal Ferrite Head, superbly wider frequen-cies with clear highs can be recorded in all their true fidelity with how noise tape. In other words, with the GX Head, a high dynamic range and excellent signal-to-noise ratio are achieved. The secret of this success lies in the head materials, superior processing technique and the focused-field recording system. The core of this quality head is made of single crystal ferrite and is mounted and set in glass. The superior high range characteristics are contri-butable to the structure of the head gap which focuses the magnetic field into a sharp oblong radius. This focused field recording system minimizes high frequency loss, eliminating undue equalization and achieving a wider dynamic range.
4-CHANNEL SURROUND STEREO
4-CHANNEL SURROUND STEREO What is all the talk about 4-channel stereo and what are the advantages? 4-channel stereo is equally as great an achieve-ment as the advancement from monaural to 2-channel stereo. Just as 2-channel stereo sound reproduction meant the exodus of flat monaural sound, this epoch-making new system eliminates the inability to pick up and reproduce pure concert hall sound. New 4-channel stereo uses 4 signal paths or sound tracks in the program material and in playback approximates the complexity of the sound waves which reach the listener's ear when attending a live concert hall performance. For playback, 4 speakers are positioned to surround the speakers each delivering "sense of presence". With the 4 speakers each delivering separate sound, you are literally surrounded with a wall of sound. This 4-dimensional sound reproduction makes conventional stereo seem empty and
speakers each delivering separate sound, you are literally surrounded with a wall of sound. This 4-dimensional sound reproduction makes conventional stereo seem empty and insufficient. AKAI's "SURROUND STEREO" supplements conven-tional stereo's 2 front speakers with two additional rear speakers to form the "2-2 system". The listener is sur-rounded by two sets of speakers (left & right front and left & right rear). This arrangement does not mean, however, that simply adding two speakers to a 2-channel system is all that is necessary for 4-channel playback. At recording time, 4 microphones are used and sound is picked up from 4 separate places. Four separate recordings are made using 4 separate channels (four tracks in one direction). This 4-channel stereo tape feeds into 4 pre-amplifiers and 4 main amplifiers to activate a 4-speaker system. Thus, at playback time, sounds from separate channels are emitted from each speaker providing the listener with a feeling that he is istening to concert hall sound from the best seat in the auditorium.
anditorium. Model GX280D-SS Stereo Tape Deck is a compatible 4-channel/x-channel model. For 2-channel operation, only the front channels are utilized. For exciting 4-channel surround stereo playback, a 4-channel external power amplifier or two 2-channel ampli-fiers can be used to activate a 4-speaker system.
| 4-Track Recording/Playback System 4 |
|---|
| 4-Channel Surround Stereo Recording/Playback 4 |
| 2-Channel Stereo Recording/Playback 4 |
| Tape Loading 4 |
| Tape Selector Switch 4 |
| Tape Speed Selection 4 |
| Direct Function Change Control System 4 |
| Fast Forward & Rewind 4 |
| Automatic Stop & Shut-Off 4 |
| How To Use The Pause Button 5 |
| How To Use The Index Counter |
| Remote Control |
| Operating Instructions |
| Connections For Playback |
| Connections For Recording |
| 4-Channel Surround Stereo Playback 8 |
| 2-Channel Stereo Playback 8 |
| Automatic & Manual Reverse Playback |
| 4-Channel Stereo Recording 10 |
| 2-Channel Stereo Recording 10 |
| Sound-On-Sound Recording 12 |
| Sound Mixing 12 |
| Tape Erasing 12 |
| Tape Splicing & Editing 13 |
| Maintenance 13 |
| Heads Should Always Be Kept Clean 1 |
| Pinch Wheel & Capstan Cleaning 13 |
| Head Demagnetizing 1 |
| Voltage & Cycle Conversion |
| Technical Data |
| Standard Accessories 1 |
| Trouble Shooting Chart 1 |
Front CH left Rear CH left Front CH right
Side A
TAPE SELECTOR SWITCH
Depress Tape Selector Switch when using Akai S.R.T. (super range tape) or other make low noise tape. This feature brings out the maximum response of low noise tape and works to change the recording equalization according to the tape. Although the GX-2800-SS exhibits a good frequency response with regular tape, this is further extended with low noise tape.
This model operates on two tape speeds; i.e., 7-1/2 and 3-3/4 ips. Simply depress 7-1/2 or 3-3/4 Tape Speed Selector Switch according to desired speed. Recording time using an 1800 ft, tape : (2-channel stereo) 3 hrs. at 3-3/4 ips and 1-1/2 hrs. at 7-1/2 ips. (4-channel stereo) 1-1/2 hrs. at 3-3/4 ips. and 3/4 hrs. at 7-1/2 ips.
The GX-280D-SS employs a 4-track system which can be used for either 4-channel or 2-channel stereo recording and playback. Select system with the Stereo Selector on front panel.
4-CHANNEL STEREO RECORDING/PLAYBACK 2-CHANNEL STEREO RECORDING/PLAYBACK
2-CHANNEL STEREO RECORDING/PLAYBACK 2-channel stereo recording and playback requires the simultaneous use of two tracks. Set Stereo Selector to 2-CH position and use only front channel controls. The first stereo recording (playback) takes place on tracks 1 and 3 and the second on tracks 2 and 4 after the reels have been
TAPE LOADING
- TAPE LOADING Place a full reel of tape on the Supply Reel Table and an empty reel on the Take-Up Reel Table. Lock reel into place pulling tip of retainer on reel shaft outward and turning to left or right. Unwind about a 75 cm length of tape from the supply reel and then thread tape properly as shown by the dotted lines in the figure. Insert end of tape in slot of empty reel and wind tape around the reel hub two or three times. Continue winding tape onto take-up reel until all tape slock basen taken up
- around the reel hub two or three times. Continue winding tape onto take-up reel until all tape slack has been taken up.
DIRECT FUNCTION CHANGE CONTROL SYSTEM
FAST FORWARD & REWIND
To effect fast forward or rewind, depress Fast Forward or Rewind Button on control panel. Use Stop Button to stop fast forward or rewind operation.
AUTOMATIC STOP & SHUT-OFF
- PERATING INSTRUCTIONS Your machine requires constant voltage for optimum performance. The GX-280DSS is equipped with a Universal Voltage solector and Cycle Conversion switch. Voltage and Cycles are preset at the factory according to destination. However, you are requested to confirm setting before attempting operation and if necessary, readjust as indicated on page 14 of this manual. If your local power source is unknown, please ask your nearest electric company for correct voltage and cycles. As dirty heads and magnetized heads become the source of loss of sound, distortion, sound drop-out, and other recording and playback failures, the heads must be kept clean and demagnetized at all times. Do not place anything on top of your machine which will obstruct the ventilator.
HOW TO USE THE PAUSE BUTTON
HOW TO USE THE PAUSE BUTTON For momentarily suspending tape travel daring recording or playback, depress Pause Button. Pause control is especially useful for editing tapes. Simply depress when certain portions of the program are not desired. After being de-pressed, the Pause Button can be locked into position by turning in direction of arrow. • Pause control is also useful for artige teerding smoothly and • Pause Control is also useful for the start of the start of the recording input level while observing VU sheets. When an optimum level has been determined, simply telease Pause Button and begin recording.
HOW TO USE THE INDEX COUNTER
Novel GUSE THE INDEX COUNTER Model GX-280D-SS is equipped with a handy 4-digit Index Counter for easy indexing. This provides an easy reference for quickly locating positions on the tape. For resetting, simply depress Reset Button.
REMOTE CONTROL
All operating functions of the GX-280D-SS can be remote controlled with Akai Remote Control unit RC-16 (optional accessory). Plug into socket provided on rear panel.
either horizontally or vertically. * If the sound sources are so far away from the microphones that the recording level controls must be turned up to maximum, some hum or noise will inevitably be recorded. A test recording is recom-mended before attempting a final recording. * Use good quality tapes. New tape gives best results. * As tapes which have not been used for a period of time may have become sticky, run once before using. * Always store tapes in a cool, dry place. Should there be a problem with your machine, write down the model and serial numbers and all pertinent data reparding warranty coverage as well as a clear description of the existing trouble and contact your nearest authorized Akai Service Station or the Service Department of Akai Electric Company, Tokyo, Japan.
- PLAYBACK. If a 4-enamine snews amplifier each to the front and rear channel jacks respectively. Please read OFERATING INSTRUCTIONS carefully prior to operation. I rand a prevecorded tape following the instructions on page 4.
2-CHANNEL STEREO PLAYBACK
.
- Load a pre-recorded tape following the instructions on page 4. Connect power cord and turn on Power Switch (A). Set Stereo Selector (B) to 2-CH position. Select tape speed with Tape Speed Selector Switch (C). Set Monitor Switch (D) to TAPE position. Depress Forward Button (E) to begin playback. Adjust external amplifier controls. To stop tape travel during playback depress Stop Button (F). Depress Reverse Button (G) for playback of reverse side or invert reels.
AUTOMATIC & MANUAL REVERSE PLAYBACK
AUTOMATIC & MANUAL REVERSE PLAYBACK For automatic reverse playback, affix about a 2.5 cm (1") long piece of sensing foil to the outside of the tape at desired reversing point. If continuous reverse between two points is desired, affix another piece of sensing tape to the inside of the tape at desired reversing point. As the foil passes the sensing pole(s) reverse is effected. Model GX-280D-SS is also equipped with a Manual Reverse Button for manual reverse playback. To effect manual reverse, depress Manual Reverse Button or control panel.
4-CHANNEL AUTOMATIC REWIND/SHUT-OFF
the power of the unit. 4-CHANNEL AUTOMATIC REWIND/ CONTINUOUS PLAYBACK Apply sensing foil to the outside of the tape for normal playback to rewind and inside for rewind to repeat at desired repeating point, and confirm that Shut-Off Button is at OUT position. When the tape reaches the place at which sensing foil is affixed, it will automatically rewind to starting position (point at which sensing tape is applied) and playback will continue. The tape will be played and rewound over and over until the unit is manually turned off.
2-CHANNEL AUTOMATIC REVERSE PLAYBACK/SHUT-OFF Apply a piece of sensing foil to the outside of the tape at desired reversing point and depress Shut-Off Button. When the tape reaches the place at which sensing foil is affixed, reverse playback is effected. At the end of reverse playback,
power of the unit. 2-CHANNEL AUTOMATIC CONTINUOUS PLAYBACK Apply sensing foil to the outside of the tape for normal to reverse playback and inside for reverse to normal playback at desired reversing points, and confirm that the Shui-Off Button is at OUT position. When the tape reaches the place at which the sensing foil is affixed, reverse playback will be effected. At the end of reverse playback (point at which sensing foil is applied) playback will continue in the opto directions.
4-CHANNEL STEREO RECORDING
- CONNET GENERAL STREETER PORTAIN SUPPORT CONNET GENERAL AND A STREETER STREE
- .
- * Load tape following instructions on page 4. Connect power cord and turn on Power Switch (A). Set Stereo Selector (B) to 4-CH position. Select tape speed with Tape Speed Selector Switch (C). Wich Reset Button (D), set Index Counter to "0000". This Index Counter furnishes a quick reference for locating positions on the tape. Set Monitor Switch (E) to SOURCE position. Adjust and balance Recording Level Controls (front and rear channel left and right) (F) while observing corresponding VU Meters. Normal recording level should not exceed "0" VU. When an optimum level has been determined, while holding Record Safety Button (G) at depressed position, depress Forward Button to begin recording. To stop tape travel during recording, depress Stop Button (H)
- 2-CHANNEL STEREO RECORDING Connect device 3-channel program source to the appropriate inputs of the GX-380D-8S as shown in CONNECTIONS FOR RECORDING DERATING INSTRUCTIONS carefully prior to operation. J Load tape following instructions on page 4.
- Connet oper cord and turn on Power Switch (A). Set Stereo Selector (B) to 2-CH position. Select tape speed with Tape Speed Selector Switch (C). With Reset Button (D), set Index Counter to "0000".
- This Index Counter furnishes a quick reference for locating positions on the tape. Set Monitor Switch (E) to SOURCE position. Adjust and balance Recording Level Controls (front channel left and right) (F) while observing corresponding VU Meters. Normal recording level should not exceed "0" VU. When an optimum level has been determined, while holding Record Safety Button (G) at depressed position, depress Forward Button to begin recording. To stop tape travel during recording, depress Stop Button (H). Invert reels for recording on reverse side.
- Button (H). Invert reels for recording on reverse side.
NOTES FOR YOUR CONVENIENCE
- OTES FOR YOUR CONVENIENCE When using Line Input Jacks for connection with the external source, the input level is adjusted with the Line Recording Level Controls. When using Din Jacks for connection with an external amplifier, or the Microphone Jacks the input level is adjusted with the Microphone Recording Level Con-
- adjusted with the Microphone Recording Level Con-trols. Microphones must not be placed on top of or too close to the recorder. Preferably, the microphones should be placed on a separate table to prevent vibrations of the recorder motor from reaching them. For best results, a distance of at least 2 meters should be maintained between microphones. The use of the Monitor Switch during recording enables correct adjustment of the sound source input level as well as comparison of the sound source input level as well as comparison of the sound source and the recording. For monitoring sound source depress Monitor Switch to IN position, and for monitoring recording depress to OUT position. To momentarily suspend reel movement during record-ing, use the Pause Button.
- For monitoring sound, use steree headphones of 8 Ω impedance. Connect headphone plag to the Headphone Jacks on front panel. The Din Jacks are used for inter-connecting the GX-2800-SS with an external amplifier. This system enables easy recording or playback through an external amplifier as the complex connection or disconnection of several separate plugs is not necessary. The GX-2800-SS is also equipped with a Din Jack Input Selector Switch. When recording from an external amplifier, if the output level of the amplifier is high, set Selector Switch to HGH position. Tor easy check of input level when using Din/Din connection cord, after connection has been made, turn input level to maximum. If VU indicator movement is limited, set switch to LOW position. If indicator moves excessively, set Selector Switch to HIGH In case the indicator shows no movement at either position, use opposite ends of the Din cord.
.
SOUND-ON-SOUND RECORDING
- st Recording Confirm that there are no connections to the Input Jacks. Set Stereo Selector to 4-CH position.
- Set Stereo Selector to 4-CH position. Plug in microphone to rear channel left Microphone Jack. Depress Monitor Switch to SOURCE position. Adjust rear channel left Microphone Recording Level Control while observing corresponding VU Meter. Depress Reset Button and set Index Counter to "0000".
- "0000".While holding Record Safety Button at depressed position, depress Forward Button to begin first record-
- ond Recording Confirm that the Monitor Switch is at SOURCE position and set Sound-On-Sound Switch at rear of unit to ON positon. Set Stereo Selector to 2-CH position.
- Meter. 15. While holding Record Safety Button at depressed
- While holding Record Safety Button at depressed position, depress Forward Button to begin second recording i.e., A-B-C. As the second recording A-B-C is being made, the first recording A-B-C is monitored through headphones. The two recordings will be completely merged on front channel tracks.... A-A'-B-B'-C-C'. For playback, rewind tape to starting point, depress Monitor Switch to TAPE position and set both recorder and external amplifier to front channel playback mode.
- Connect power cord and turn on Power Switch. Set Stereo Selector to 2-CH or 4-CH position as desired. Select tape speed with Tape Speed Selector Switch. With Reset Button, set Index Counter to "0000". This Index Counter furnishes a quick reference for locating positions on the tape. Pulg in microphone(s) to Microphone Jack(s) and connect line output of external source to Line Input of the GX-280D-SS. Set Monitor Switch to SOURCE position. Adjust and balance microphone input level with Microphone Recording Level Control and line input level with Line Input Level Control and line input level with Line Input Level Control while observing corresponding VU Meters. Normal recording level. When an optimum level has been determined, while holding Record Safety Button at depressed position, depress Forward Button to begin recording. To stop tape travel during recording, depress Stop Buttons Se AUTOMATIC STOP & SUIT-OFF. If recording is made in 2-channel, invert reels for recording on reverse side. * Insuc connections smultaneous. * Tor Jayback, operate the Stereo Selector according to channels used in making recording.
TAPE ERASING
TAPE ERASING Any signals previously recorded on the tape will auto-matically be erased as a new recording takes place. For erasing only, load a tape and set recorder to recording mode. Model GA:280D-28 is equipped with separate 2-channel and 4-channel erase heads. For full track erase, set Stereo Selector to 4-CH position and for 2-channel erase, set to 2-CH position. No plugs should be connected to the input jacks and input volume should be kept at minimum.
TAPE SPLICING & EDITING
Cut tage diagonally with an overlap so that the ends are lined up. Cover aligned ends with splicing tage. Press firmly exerting pressure to secure ends evenly. Trim off excees splicing tage cutting into recording tage very slightly to eliminate the possibility of a sticky splice. Tage splicing using scissors requires skillful work. Akai Tage Splicer Model A&3 is recommended for smooth and easy tage
HEADS SHOULD ALWAYS BE KEPT CLEAN
KEPT CLEAN For quality performance, it is imperative that the head block be key clean at all times. Dust and magnetic particles tend to deposit on the heads after probaged use of the unit, deteriorating sound quality and sensitivity. The GX Heads do not normally require cleaning. However, if old tapes or tapes which have been spliced are used, head cleaning is recommended. Clean by rubbing the entire head surface (do not scratch) with a cotton swab stick soaked in Akai cleaning fluid (from HC-500 Head Cleaning Kit) or alcobol
PINCH WHEEL & CAPSTAN CLEANING
HEAD DEMAGNETIZING
HEAD DEMAGNETIZING Normally, the steel pole pieces which form part of the recording and playback heads become slightly magnetized. The effect of magnetization is that it causes considerable dropout or introduces noise into your recordings. It is, therefore, recommended that head demagnetizing be per-formed periodically. This can be accomplished with a bulk head demagnetizer by bringing it close to the heads and making several circular motions over all head surface areas as well as the head housing. • Be use to cut off the power of the unit pior to demagnetizer to on our semestized toos in the vicinity of the head. • Do not use magnetized toos in the vicinity of the head. • Other the program of the demagnetizer doise to VU Meters.
60 Hz
50Hz
VOLTAGE & CYCLE CONVERSION
COLTAGE & CYCLE CONVERSION CBC SA, and UL Standard models are not equipped with a Voltage Selector or Cycle Conversion Switch. Therefore, voltage and cycle conversion is not necessary. If your machine corresponds to any of these standards, please disregard all references to voltage and cycle adjustment unugbout this manual. WOITAGE WOITAGE OUTAGE OU
CYCLE Correct tape speed cannot be obtained if the Cycle Conversion Switch located on the rear panel of the GX-280D-SS is not properly positioned. Disconnect power cord and set to 50Hz or 60 Hz according to area power
STANDARD ACCESSORIES
| Connection Cord | 1 | set | ||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Demonstration Tape | . 1 | |||||||||||||||||||||||||||
| Empty Metallic Reel | . 1 | |||||||||||||||||||||||||||
| Sensing Tape | . 1 | |||||||||||||||||||||||||||
| Spare Fuse | • | 1 | set | |||||||||||||||||||||||||
| Operator's Manual | . 1 | |||||||||||||||||||||||||||
| * Spare fuses are not in ard models. | cl | u | de | 20 | w | it | h | ( | 21 | 3 | 3, | ( | CS | S, | ٩., | 1 | U | L, | , : | a 1 | 10 | 1 | L | A | 5 | it | and |
Track System ...... 4-track 4/2-channel compatible stereo
| Maximum Reel | |
|---|---|
| Capacity | 7" reel |
| Tape Speed | 7-1/2 and 3-3/4 ips (±0,59 |
| Wow & Flutter | Less than 0.10% RMS at |
| Less than 0.15% RMS at 3 | |
| Equalization | Correct equalization for |
| playback of tapes recorde | |
| to the NAB curve. | |
| Frequnecy Response . | (Using low noise tape) |
| 20 Hz to 25,000 Hz (±3 d | |
| at 7-1/2 ips | |
| 30 Hz to 20,000 Hz (±3 d | |
| at 3-3/4 ips | |
| (Using regular tape) | |
| 30 Hz to 23,000 Hz (±3 d | |
| at 7-1/2 ips | |
| 30 Hz to 19,000 Hz (±3 d | |
| at 3-3/4 ips | |
| Distortion | 0.8% (1,000 Hz "0" VU) |
| Signal-To-Noise | |
| Ratio | 55 dB |
| Erase Ratio | Better than 70 dB |
| Bias Frequency | 110 kHz |
| Heads | (4) GX recording and play |
| heads, full-track erase, | |
| 2-channel erase heads. | |
| Motors |
(3) One servo-motor for d
capstan drive and two 6-p |
Fast Forward & Rewind Time Within 90 seconds using a 1,200 ft. tape. Recording Capacity -2-channel stereo : 2 hrs. (1,200 ft. tape, 3-3/4 ips) 4-channel stereo : 1 hr. (1,200 ft. tape, 3-3/4 ips) Output Jacks Line (4): 1.23 V (*0" VU) 100 Ω; Required load impedance : more than 25kΩ Phone (2): 40 mV/8 Ω Input Jacks Microphone (4): 0.5 mV/10 kΩ Line (4): 0.1 V/150 kΩ Dn Jacks (2): 0.4 V(60 mV(Hgh) 10 mV (Low) Semi-Conductors 68 billion transistors, Fast Forward & Rewind Time ..... 10 mV (Low) Semi-Conductors .... 68 silicon transistors, 52 diodes Integrated Circuits .... 4 Integrated Circuits .... Power Supply ..... UL & LA models : 120 V, 60 H Power Consumption ... 140 W Dimensions ....................................
* For improvement purposes, specifications and design are subject to change without notice.
MANUFACTURED & DISTRIBUTED BY AKAI ELECTRIC CO., LTD. AKAI TRADING CO., LTD.
12-14, 2-chome, Higashi-Kojiya, Ohta-ku, Tokyo, Japan
AKAI AMERICA, LTD.
2139 E. Del Amo Blvd., Compton, Calif., 90220, U.S.A. TELEPHONE: (213) 537-3880 TELEX: 67-7494
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