1. Introduction
This manual provides essential information for the safe and efficient operation of your SANSUI AU-D707 Preamplifier. Please read this manual thoroughly before using the unit and retain it for future reference. The AU-D707 is a high-fidelity integrated amplifier designed to deliver exceptional audio performance.
Image showing the front panel of the SANSUI AU-D707 Preamplifier, featuring various control knobs and input selectors.
2. Setup and Connections
Proper setup is crucial for optimal performance and safety.
2.1 Unpacking and Placement
- Carefully remove the amplifier from its packaging.
- Place the unit on a stable, level surface with adequate ventilation. Ensure there is sufficient space around the unit for heat dissipation.
- Avoid placing the amplifier near heat sources, in direct sunlight, or in areas with high humidity or dust.
2.2 Speaker Connections
Connect your speakers to the speaker terminals on the rear panel. Ensure correct polarity (positive to positive, negative to negative) for each channel. The AU-D707 supports speaker impedances between 4 and 16 ohms.
2.3 Audio Source Connections
Connect your audio sources (e.g., turntable, CD player, tuner, tape deck) to the corresponding input jacks on the rear panel.
- Phono-1 (MM/MC): For turntables. Select MM (Moving Magnet) or MC (Moving Coil) based on your cartridge type.
- Phono-2 (MM): For turntables with Moving Magnet cartridges.
- AUX: For general audio devices like CD players or digital audio players.
- Tuner: For radio tuners.
- Tape Play 1, 2: For connecting tape decks or other recording devices.
2.4 Power Connection
After all audio connections are made, connect the power cord to the amplifier and then to a suitable AC outlet. Ensure the power switch is in the OFF position before connecting to power.
3. Operating Instructions
Familiarize yourself with the controls for optimal listening experience.
3.1 Power On/Off
Press the POWER button on the front panel to turn the amplifier ON or OFF.
3.2 Input Selection
Use the INPUT SELECTOR knob to choose the desired audio source (Phono-1, Phono-2, AUX, Tuner, Tape Play 1, Tape Play 2).
3.3 Volume Control
Adjust the overall sound level using the large VOLUME knob. Start at a low volume and gradually increase to a comfortable listening level.
3.4 Tone Controls
- BASS: Adjusts the low-frequency response.
- TREBLE: Adjusts the high-frequency response.
- TONE SELECTOR: Allows selection of turnover frequencies for Bass (300Hz, 150Hz) and Treble (6kHz, 3kHz) controls, providing more precise tonal adjustments.
3.5 Subsonic Filter
Engage the SUBSONIC FILTER to cut off very low-frequency rumble (e.g., from warped records) that can cause speaker distortion without contributing to audible music.
3.6 Loudness
The LOUDNESS function boosts bass and treble frequencies at low volume levels to compensate for the human ear's reduced sensitivity to these frequencies.
3.7 Headphone Output
Connect headphones to the PHONES jack for private listening. Connecting headphones will typically mute the main speaker outputs.
4. Maintenance
Regular maintenance helps ensure the longevity and performance of your amplifier.
- Cleaning: Wipe the exterior of the unit with a soft, dry cloth. For stubborn dirt, use a slightly damp cloth and then dry thoroughly. Avoid abrasive cleaners or solvents.
- Ventilation: Ensure that the ventilation openings are not blocked by dust or other objects. Periodically clean dust from the vents using a soft brush or vacuum cleaner.
- Liquid Spills: Never allow liquids to enter the unit. In case of a spill, immediately disconnect power and consult a qualified service technician.
- Internal Components: As an older audio component, the AU-D707 may require periodic professional maintenance, such as replacement of aluminum electrolytic capacitors and relays, to maintain optimal performance. Do not attempt internal repairs yourself.
5. Troubleshooting
If you experience problems with your amplifier, refer to the following common issues before seeking professional service.
5.1 No Power
- Check if the power cord is securely plugged into both the amplifier and the wall outlet.
- Ensure the POWER button is pressed.
- Verify that the wall outlet is functional by plugging in another device.
5.2 No Sound
- Confirm that the correct input source is selected.
- Check all speaker connections for proper polarity and secure fit.
- Ensure the VOLUME knob is turned up.
- If headphones are connected, disconnect them to check speaker output.
- Verify that your audio source (e.g., CD player) is playing and its output is connected correctly.
5.3 Distorted Sound or Noise
- Check all cable connections for looseness or damage.
- Ensure speaker wires are not frayed or shorting.
- Reduce the volume to see if distortion decreases.
- If using a turntable, ensure the Phono MM/MC setting matches your cartridge.
- Try a different audio source to isolate the problem.
If the problem persists after checking these points, contact a qualified service technician.
6. Specifications
Detailed technical specifications for the SANSUI AU-D707 Preamplifier.
6.1 Power Amplifier Section
| Effective Output | 90W + 90W (10Hz-20kHz, THD 0.008%, 8Ω) 90W + 90W (1kHz, THD 0.003%, 8Ω) |
| Total Harmonic Distortion | 0.008% or less (10Hz-20kHz, at effective output, 8Ω) |
| Intermodulation Distortion (70Hz:7kHz=4:1) | 0.008% or less |
| Output Bandwidth | 3Hz-70kHz (IHF, both channels, 1kHz, 8Ω) |
| Damping Factor | 100 (IHF, both channels, 1kHz, 8Ω) |
| Frequency Response | DC-500kHz, +0 -3dB |
| Input Sensitivity/Impedance (1kHz) | 1V/47kΩ |
| SN Ratio | 125dB or more (IHF, A-network, short circuit) |
| Channel Separation (IHF, 1kHz) | 90dB or more |
| Rise Time | 0.5μsec |
| Slew Rate | ±200V/μsec |
6.2 Preamplifier Section
| Input Sensitivity/Impedance (1kHz) | Phono-1 MM: 2.5mV/47kΩ Phono-1 MC: 0.1mV/100Ω Phono-2 MM: 2.5mV/47kΩ AUX, Tuner, Tape Play 1,2 (PIN): 150mV/47kΩ |
| MC Compatible Impedance | 100Ω or less |
| Phono Maximum Allowable Input (1kHz) | Phono MM: 350mV (THD 0.01%) Phono MC: 30mV (THD 0.03%) |
| Output Voltage (1kHz) | Tape Rec 1,2 (PIN, at 47kΩ): 150mV Pre Out (at 47kΩ): 1V Max Pre Out (THD 0.05%, at 47kΩ): 4V |
| Output Impedance (1kHz) | Tape Rec 1,2: 600Ω or less |
| Total Harmonic Distortion | Phono MC (1kHz, 6V): 0.01% or less Phono MM (20Hz-20kHz, 6V): 0.005% or less AUX, Tuner, Tape Play 1,2 (20Hz-20kHz, 1V): 0.005% or less |
| Intermodulation Distortion (70Hz:7kHz=4:1) | AUX, Tuner, Tape Play 1,2 (1V): 0.005% or less |
| Frequency Response | RIAA Deviation (Phono 1,2, 20Hz-20kHz): ±0.2dB AUX, Tuner, Tape Play 1,2: 5Hz-100kHz, +0 -1dB |
| SN Ratio (IHF, A-network, short circuit) | Phono MC (input conversion): -154dBV Phono MM: 90dB or more AUX, Tuner, Tape Play 1,2: 100dB or more |
| Channel Separation (IHF, 1kHz) | Phono MC: 70dB or more Phono MM: 70dB or more AUX, Tuner, Tape Play 1,2: 80dB or more |
| Input Separation (input short, 1kHz) | Tuner↔Phono MM: 90dB or more Tape Play 1, 2↔Phono MM: 90dB or more Tuner↔Tape Play 1, 2: 90dB or more Tape Play 1↔Tape Play 2: 100dB or more |
| Tone Control | Bass: ±6dB (50Hz) Tone Selector (Turnover Frequency): 300Hz, 150Hz Treble: ±6dB (15kHz) Tone Selector (Turnover Frequency): 6kHz, 3kHz |
| Subsonic Filter | 16Hz (-3dB, 6dB/oct) |
| Loudness (at Volume -30dB) | +10dB (50Hz), +4dB (10kHz) |
| Headphone Output | 120mW (8Ω) |
6.3 General
| Load Impedance | 4-16Ω |
| Rated Power Consumption | 230W |
| External Dimensions (W x H x D) | 430 x 168 x 428mm |
| Weight | 20.1kg |
7. Warranty and Support
Specific warranty information for the SANSUI AU-D707 is not available in the provided product data. For details regarding warranty coverage, service, or technical support, please refer to the original purchase documentation or contact the retailer or manufacturer directly.
