Country of Manufacture:Japan
Speeds: 1 7/8, 3 3/4
Max Reel Size("): 3"
Number of heads: 2
Head Composition: Permalloy
Head Configuration: Mono - Full Track
Frequency Response:3¾ ips: 90Hz - 9.5kHz
Wow and Flutter:less than 0.3% at 3¾ ips
Signal-to-Noise Ratio:better than 40dB
Sound quality rating:5 / 10
Long-term reliability rating: 5 / 10
The 905-A was a solid-state, battery-operated portable half-track mono machine. It had two speeds (3¾ & 1 7/8ips) and a maximum reel size of 3¼”. As the name suggests, the main feature of this unit was its automatic voice-activated recording. In addition, recording was controlled by Sony’s new AVC (automatic volume control) and hence the unit did not feature any record level control or indicator.
Power supply was from either 4 “AA” Nickel/Cadmium batteries
or mains power unit. Away from home-base, it was a self-contained 4lb
portable unit with in-built monitor speaker, back at home it could be
plugged into its own ‘docking-station’ power supply and amplifier/speaker
unit for ‘hi-fi’ reproduction. The base-unit also incorporated a battery-charger
for the “AA” Nickel-Cadmium cells.
Inputs: microphone / Outputs: monitor headset / Dimensions: recorder: 8¾ x 6½ x 2¾” (220 x 165 x 68 mm) speaker / amplifier: 8¾ x 6½ x 4″ (220 x 165 x 98 mm) / Weight: recorder: 4¼ lbs 2.7 kg) speaker / amplifier: 3¾ (1.7 kg) / half-track mono