Sansui AU-7700 Stereo Amplifier
Operating Instructions
Introduction
We are grateful for your choice of the Sansui AU-7700 stereo amplifier. Before you begin to operate it, please read this booklet of operating instructions carefully. You will then be able to connect and operate it correctly, and enjoy its superb performance for years.
Functional Features
- Terminals for connecting up to two pairs of speakers.
- Circuits for handling two tape decks provided, facilitating tape copying (dubbing).
- Terminals for connecting up to two turntables.
- Selectable input impedance for the PHONO-1 circuit (30kΩ, 50kΩ, or 100kΩ) to match the cartridge's load resistance.
- Versatile tone control for bass, midrange, and treble, with selectable turnover frequencies.
- High and low filter switches to eliminate unpleasant noise.
Important Precautions
- Do not obstruct the ventilation openings of the cabinet.
- Avoid placing the set in extremely hot, dusty, or near heating appliances.
- Insert pin jack covers into unused pin jacks to prevent dust accumulation.
- Ensure the shelf board is thick and strong if placing the set on a shelf.
Heat Radiated by the Set
Transistors are sensitive to heat. The enclosure is designed for good heat dissipation. Avoid placing objects on ventilation openings or using the set in a closed box for extended periods, as this can lead to breakdown. Ensure good air circulation around the set. Removing the enclosure or bottom plate for ventilation is dangerous and undesirable for electrical performance.
AC Outlets
The rear panel has three AC outlets: one 'SWITCHED' outlet controlled by the front-panel POWER switch, and two 'UNSWITCHED' outlets. The SWITCHED outlet has a 100-watt capacity, while the UNSWITCHED outlets have a combined capacity of 250 watts. Do not connect equipment exceeding these capacities, as it is dangerous. Check the equipment's specification chart or the unit itself for its power consumption rating.
Rear-Panel Connections
Diagram illustrating connections for Tape Player/Deck, Speaker Systems A & B, Turntables 1 & 2, Tuner, and AUX terminals. It also shows the AC outlet and PRE/MAIN SEPARATE switch.
Connection of Speaker Systems
Connect speaker systems to the SPEAKERS SYSTEM-A or -B terminals. Ensure correct left/right and positive/negative connections. For two pairs of speakers, each should have an impedance of more than 8 ohms when using the A+B setting. Using systems with lower impedance can cause breakdown or reduce composite speaker impedance.
Connecting Headphones
Connect stereo headphones to the PHONES jack on the front panel. Sound from speakers will also be heard unless the SPEAKERS switch is set to OFF. To listen privately, turn the SPEAKERS switch to OFF.
If Speaker Systems are Out of Phase
Reverse-phasing can cause sound dropouts and damage stereo perspective. Correct by ensuring correct polarity of speaker cables. This can be checked by setting the MODE switch to MONO; the sound should appear to come from a point midway between the speakers.
Basic Operating Procedures
- POWER: Raise the lever switch to ON to turn the set on; push down to OFF to turn it off. Reduce volume before operating switches.
- SELECTING SPEAKER SYSTEMS: Use the SPEAKERS switch (OFF, A, B, A+B) to select speaker output.
- SELECTING PROGRAM SOURCE: Use the SELECTOR switch to choose between PHONO-1, PHONO-2, TUNER, AUX-1, AUX-2, or TAPE DECK inputs.
- TAPE PLAYBACK AND RECORDING: Use the TAPE PLAY switch for playback or monitoring recordings. For dubbing tapes, use the COPY 1-2 or COPY 2-1 positions.
- STEREO VS. MONO: Use the MODE switch to select NORMAL (stereo), REVERSE (stereo with reversed channels), or MONO.
- ADJUSTMENT OF VOLUME: Use the VOLUME control for overall volume. Use the MUTING switch to temporarily reduce volume by -15dB or -30dB.
Left & Right Balance Adjustments
Use the BALANCE control (outer ring of the VOLUME control) to adjust the volume difference between left and right speakers. For precise stereo balance, push down the MODE switch and adjust the BALANCE control.
Controlling Sound to Your Taste
Tonal Quality
Push the TONE & FILTER switch to the "TONE & FILTER" position. Adjust the BASS, MIDRANGE, and TREBLE controls for desired tonal balance. Use the BASS and TREBLE Tone Selectors to adjust the frequency range affected by the respective controls.
Set the TONE & FILTER switch to "DEFEAT" for a flat response, bypassing tone controls. Set to "FILTER ONLY" to use filters without tone controls. "DEFEAT" completely separates the tone control and filter circuits.
LOUDNESS Switch
Use the LOUDNESS switch (LOW BOOST or HIGH & LOW BOOST) to accentuate lows and highs at low listening volumes, compensating for the ear's reduced sensitivity.
Eliminating Noise
Set the TONE & FILTER switch to "FILTER ONLY" or "TONE & FILTER". Use the LOW FILTER switch (60Hz or 20Hz) to cut low-frequency noise like hum. Use the HIGH FILTER switch (7kHz or 12kHz) to cut high-frequency noise like record scratches or hiss.
Playing Records and Listening to Radio Broadcasts
Turn the SELECTOR switch to PHONO-1/2 for records or TUNER for radio. Adjust other controls as needed. The PHONO-1 PICKUP LOAD SWITCH adjusts input impedance to match the cartridge for optimal high-frequency response.
Tape Playback and Recording
Set the TAPE PLAY switch to the appropriate deck for playback or recording. For dubbing tapes, use the COPY 1-2 or COPY 2-1 positions. The AUX terminals can be used for playback from a third tape deck.
Copying a Recorded Tape
Instructions are provided for dubbing tapes between TAPE DECK-1 and TAPE DECK-2. The TAPE PLAY switch settings for dubbing and monitoring are detailed in a table. A third tape deck can be connected to AUX terminals for playback.
Conditions Mistaken for Breakdowns
This section provides a troubleshooting guide for common issues related to TUNER, TURNTABLE, TAPE DECK, and GENERAL operation. It lists symptoms, probable causes, and recommended actions.
Simple Maintenance Hints
- Connection Cords: Ensure firm connections and use shielded cords where appropriate. Keep cords as short as possible.
- Short-Circuit Pin Plugs: These are used to short PHONO-2 jacks when not in use. Reposition them for PHONO-1 if using that input, or store them safely if both are used. Do not insert into output jacks.
- PRE/MAIN SEPARATE Switch: Keep in the "CONNECTED" position unless using external preamplifiers or power amplifiers. Turn the set's POWER switch OFF before sliding the switch.
Before Sending the Set Out for Servicing
Confirm connections and operating procedures first. Check power, tape play switch, selector switch, and volume control. Inspect all connection cords and speaker connections. If issues persist, contact a dealer or authorized service station.
About the Voltage Adjustment
The set is adjusted for the local voltage. If moving to a different region, adjust the Voltage Selector Plug on the rear panel and potentially replace the power fuse accordingly (6A for 100-117V, 3A for 220-240V).
Should the Power Fuse Blow
If the Power Indicator does not light, the power fuse may have blown. Replace it with a new glass-tubed fuse of the correct rating. Never use a fuse of a different capacity or a piece of wire.
Specifications
Detailed specifications for the Sansui AU-7700, including power output, load impedance, frequency response, total harmonic distortion, channel separation, input sensitivity, dimensions, and weight.
List of Accessories
Includes Pin Jack Covers, Operating Instructions, and Operating Instructions Sheet.
International Warranty
Information regarding the international warranty applicable to Sansui products, including terms, exceptions, and conditions for service.
Authorized Service Stations
Lists of authorized Sansui service stations in the USA, Canada, and worldwide.
