Audio Database


This is a pre-main amplifier that is the highest grade model of Sansui's PB series and an upgraded version of AU 777 d.
Aiming for more faithful sound reproduction, it was developed by accumulating thorough hearing tests.

The main amplifier section uses a 2-stage differential amplifier circuit and a fully connected system with two power supplies (plus and minus) without an output capacitor. This makes NFB uniform from the ultra-high band to the ultra-low band and improves various characteristics.

The equalizer stage uses a 3-stage E-E NF type PNP silicon transistor with low noise, and achieves low noise, low distortion, wide dynamic range and high stability.

A direct-coupled circuit is used as much as possible for the amplifier circuit, and a Mylar capacitor is used as much as possible for the necessary part of the coupling capacitor. Electrolytic capacitors with large phase distortion in the high frequency range and poor transmission characteristics are eliminated.

The tone control part uses SANSUI's original triple tone control, and not only Bass and Treble but also Midrange can be adjusted.
It uses a tone selector that switches between two frequencies for both the defeat point and the rising / falling point, and a click-step method with 2 db steps for low and high tones and 1 db steps for middle tones for precise adjustment.

Can be used independently by separating the pre-main part.

Two tape decks can be used simultaneously and a TapetoTape reprint switch is mounted.
It also includes a stereo balance check circuit, level adjuster, NF low / high filter, tuner selector, microphone input jack, muting switch, program indicator, headphone jack and DIN connector.

The wood case was sold separately.

Model Rating
Type Pre-main amplifier
Power Amplifier Unit
Effective power 70W/70W (4 Ω)
80W/80W (8 Ω)
Music Power (IHF) 180W (4 Ω)
140W (8 Ω)
Total harmonic distortion factor 0.4%
Cross modulation distortion factor 0.4%
Power Band With (IHF) 10 Hz to 30 kHz
Frequency characteristic 5 Hz to 100 kHz
Stereo separation 50dB
Hum and noise 100dB
Input Sensitivity / Impedance 1V/40k Ω
Load impedance 4 Ω ~ 16 Ω
Damping factor 45 (8 Ω)
Preamplifier Section
Rated output 1V
Total harmonic distortion factor 0.1%
Frequency characteristic 15 Hz to 70 kHz
Hum and noise (IHF) Phono1, 2 : 80 dB
Tuner, Aux : 85 dB
Input sensitivity Phono1, 2 : 2 mV
Tuner, Aux, and Tape mon (Pin/Din) : 200 mv
Recorded output Tape rec(Pin):200mV
Tape rec(Din):30mV
Tone control Bass : + 12 dB ~ -8dB (20 Hz)
Midrange : ± 5 dB (1 kHz, 2 kHz)
Treble : + 12 dB ~ -8dB (20 kHz)
Tone selector Bass : Defeat, 200 Hz, 400 Hz
Midrange : Defeat, 1 kHz, 2 kHz
Treble : Defeat, 6 kHz, 3 kHz
Low filter -20dB(20Hz)
High filter -18dB(20kHz)
Muting -20dB
Power consumption 370W
External dimensions Width 461.5x Height 155x Depth 316 mm
Weight 17.5kg
Sold Separately Wood Case C-17 (¥ 3,900)