Philips EL 3581

The Philips EL3581 is a compact, AC‑powered dictation‑grade reel‑to‑reel recorder from around 1960, designed for office and telephone recording rather than hi‑fi music use.

Role and basic design

• Intended as a dictaphone/telephone recorder, not a domestic music deck, so it prioritizes portability and speech intelligibility over bandwidth and wow/flutter performance.​

• Uses 3‑inch open reels housed in a special Philips cartridge for very fast loading; the reels can be removed from the cartridge and played on other machines if needed.​

• Built as a small table‑model unit with an optional dedicated table, footswitch, and accessories for desk use.​​

Tape format and transport

• Track format: full‑track mono on one tape side (a 2‑track tape overall: one track per side, not stereo).

• Tape speed: approximately 4.75 cm/s (1⅞ ips), typical dictation speed; this is confirmed by comparative playback on another deck in user tests.​​

• Drive system: rim‑drive, not capstan‑drive. The tape speed is taken from the reel hub rather than a capstan/pinch‑roller, which simplifies mechanics but increases wow & flutter—hence period comments that wow/flutter is “very high.”​​

Electronics and acoustics

• Electronics: 2‑valve (tube) amplifier; all‑tube signal path with simple fixed‑level recording (no user record‑level control, just a preset gain).​​

• Power output: about 1 W into its transducer.​

• Bias: uses AC bias for recording, giving cleaner speech than simple DC‑bias dictation machines.​

• Microphone/speaker: supplied electrodynamic microphone with built‑in speaker and control switch; the mic acts both as input and as the playback loudspeaker, and also carries a start/stop/record switch in the shell.​​

• Outputs: DIN connector for feeding an external amplifier or headphones.

Power supply, size, and build

• Power: AC‑only, multi‑voltage primary: 110, 117, 127, 220, 245 V, 50/60 Hz; power consumption around 30 W.​

• No battery operation, despite the portable format.​​

• Cabinet: plastic case (not Bakelite) with metal chassis inside.​

• Dimensions: roughly 250–260 × 100–110 × 190–195 mm (about 10 × 4 × 7.5–7.7 in).

• Weight: approximately 3.5–3.7 kg.

Operational quirks and use

• Start/stop and record can be controlled either via the foot switch or the microphone’s top switch, which locks for continuous play/record.​

• Records on the opposite half of the tape compared to standard 2‑track music recorders, so tapes may play “backwards” on normal machines unless you can select the other track; conversely, tapes recorded on a conventional 2‑track machine will replay reversed on the EL3581.​​

• Because of rim‑drive and dictation speed, speed stability and bandwidth are modest, but users report “nice and clear” speech quality at low listening levels.​​

In short, EL3581 is best seen as a specialized, compact dictation recorder with clever cartridge loading and mic‑speaker integration, technically interesting but not suited to hi‑fi music recording by modern standards