Country of Manufacture:Japan
Speeds: 1 7/8, 3 3/4
Max Reel Size("): 7"
Number of heads: 2
Head Composition: Permalloy
Head Configuration: Mono - Dual Track
# Motors: 1
Frequency Response:120 - 6kHz at 3 ¾ ips and 120 - 3kHz at 1ips
Wow and Flutter:7(DIN): less than 0.4%
Sound quality rating:5 / 10
Long-term reliability rating: 5 / 10
The RD-504 was an all-transistor, AC/battery twin track portable mono recorder with two speeds ( 3¾ and 1 7/8 ips) and a five inch reel capacity.
Features tone control switch (low/high), automatic level control, remote control (switch on mic), a
VU meter which doubled as battery indicator and an elliptical internal speaker.
The RD-504 came with a 5-inch reel of tape, take-up spool, dynamic microphone with remote start/stop switch, tape and a radio lead and had a recommended retail price of £27 6s (UK).
Record level: VU meter which doubles as battery indicator / Semiconductors: SB77, 3 x 2SB75, 2 x 2SB156 / Position indicator: 3 digit index counter / Heads: 1 combined record / playback and one erase / Motors: single / Audio output: 1 watt max, 800 mW undistorted / Dimensions: 12.4 × 9.6 × 4.1 inches (315 × 245 × 105 mm) / Weight: 4.4 lbs (2kg) / Batteries: 6 × 1.5V / 2 track mono