Audio Database

SA-71
Commentary

Pre-main amplifier with all-transistor configuration.

National's unique MFB system is adopted.

OTL system is adopted.

Built-in automatic stabilizer prevents transistor damage.

The MFB switch can be used for ordinary speakers.

Model Rating
Type Pre-main amplifier
Input terminal Aux, Tuner, Phono, Tape Mic
Input Impedance (1 kHz) Phono, Tape, Mic : 30k Ω
Aux, Tuner : 100k Ω
Output 50W(25W+25W)
Tone control CR Type ± 16 db
Rumble filter 70 Hz, -12dB/oct.
Scratch filter 6 kHz, -12dB/oct.
Loudness control Switch Switching, Continuously Variable Type
Load impedance 8 Ω ~ 16 Ω
Semiconductor used
Transistor : 2SB-173x8
2SB-345x2
2SA-249x2
2SB-178Bx2
2SD-178Bx2
2SB-309Ax4
Diode : OA-70x2
SW-1x2
SD-1x1
SV-1x4
Pwer 100 VAC, 50Hz/60Hz
External dimensions Width 390x Height 148x Depth 299 mm
Weight 13.8kg