Philips EL3555

The Philips EL3555 (including variants like EL3555A /00, /54, or rebranded as Maestro 44 in some markets, or Norelco in export regions) is a mid-to-late 1960s consumer reel-to-reel tape recorder, produced approximately 1966–1969. It was part of Philips' EL35xx series and represented one of the last hybrid (tube + transistor) designs before Philips fully transitioned to solid-state in higher-end models like the N4408 series.

This was a four-track (quarter-track) stereo-capable machine: it supported mono recording on either forward or reverse tracks and stereo playback (with external amplification for full stereo separation), plus facilities for duoplay (multi-track overdubbing) and multiplay (bounce recording) when paired with an external preamp. It featured built-in speakers for self-contained mono/stereo monitoring, making it a versatile "family" or home hi-fi recorder for music, radio dubbing, and voice.

Key Technical Specifications

• Recording/Playback System — Four-track (quarter-track); mono recording (tracks 1 or 4 forward, 3 or 2 reverse); stereo playback via external amp; duoplay/multiplay overdub capabilities (requires companion preamp like EL378x for advanced bouncing).

• Tape Speeds — Three speeds:1⅞ ips (4.75 cm/s, often listed as "1 ips" in rounded marketing)
  3¾ ips (9.5 cm/s)
  7½ ips (19 cm/s) (The inclusion of 7½ ips made it more capable for music than slower-speed-only budget models.)
  

• Reel Size — Up to 7 inches (18 cm) maximum diameter (supports standard, LP, DP, and TP tapes).

• Frequency Response (approximate, within ~6 dB as per period reviews; varies by tape and condition):At 7½ ips: 40 Hz – 18,000 Hz
  At 3¾ ips: 60 Hz – 15,000 Hz
  At 1⅞ ips: 60 Hz – 10,000 Hz Respectable for a consumer hybrid deck—good extension at higher speeds for the era.
  

• Wow & Flutter — Around 0.2–0.3% at 7½ ips (smooth single-motor belt/idler drive; typical consumer figures, with some reports of tape overrun on fast wind if idlers worn).

• Signal-to-Noise Ratio — Approximately 45–50 dB (benefited from germanium transistor preamp stages reducing front-end noise compared to full-tube designs).

• Heads — 2 heads: combined record/playback (permalloy) + erase head; stereo configuration.

• Drive System — Single asynchronous motor; belt drive to capstan/flywheel (main belt prone to hardening); idler tires for transport; mechanical brakes; fast wind/rewind ~1,800 ft in ~3 minutes.

• Electronics — Hybrid: Germanium transistor preamplifier stages (for low-noise input) + vacuum tube output amplifiers (typically 2× ECL82 pentode-triode for power stages) + EM87 magic eye recording level indicator; printed circuit boards; no power transformer in some clever designs (uses motor windings).

• Amplification & Speakers — Built-in stereo-capable amplifiers; dual internal loudspeakers (e.g., 5×7" Philips types, one in cabinet + one in detachable lid); output power ~2.3 W per channel across 5.6 ohms; separate tone controls possible in variants.

• Inputs — Microphone (~0.25 mV / 2 kΩ); radio/line/record player/second recorder (~200 mV / 500 kΩ); mixing controls for multiple sources; DIN connectors typical (some export units had ¼" jacks).

• Outputs — Internal speakers; external speakers; headphones; high-level line out (~50 kΩ); DIN-style.

• Features —Track selector and direction switching.
  Recording level mixing controls.
  Magic eye (EM87) indicator.
  Pause, fast wind/rewind, auto-stop (limited modes).
  Tape counter.
  Portable/tabletop design with lid and handle.
  

• Power — AC mains (100–135 V or 200–250 V switchable; multi-voltage export models; 50/60 Hz adaptable); consumption ~75 W.

• Build & Dimensions — Tabletop case with detachable lid (speakers in lid/cabinet); approx. 445 × 349 × 216 mm (17.5 × 13.75 × 8.5 inches) or close (some list 440 × 215 × 340 mm); weight ~28 lb (12.7 kg).

• Manufacturing — Primarily Netherlands/Austria (Philips facilities); some regional assembly.

Performance & Legacy Context

The EL3555 was praised in 1967 reviews (e.g., Amateur Tape Recording) as good value at ~75 guineas, offering true stereo playback, three speeds including 7½ ips for better music fidelity, and hybrid electronics that combined tube "warmth" in output with transistor quietness upfront. It sounded surprisingly good through its built-in speakers or external hi-fi, making it popular for home/school use (e.g., recording plays or music). It bridged the gap from earlier EL35xx models (like EL3553: transistor, 2 speeds, mono-focused) and led toward the all-transistor N-series (e.g., N4408 successor in 1967, dropping tubes entirely).

Compared to predecessors:

• EL3553 (1965–68): Fully transistor, 2 speeds (1⅞ & 3¾ ips), mono record/stereo play via external, 7" reels—simpler/budget.

• EL3552 (1965–67): Hybrid/single transistor + tubes, single speed (3¾ ips), half-track mono, smaller reels—more basic. The EL3555 added stereo capability, three speeds, and better response, positioning it as a mid-tier "hi-fi" consumer deck.

Common issues today: Belt/idler deterioration (slipping, tape overrun on FF/REW), capacitor drying (especially electrolytics—frequent blowouts noted), tube aging (ECL82 output, EM87 eye), germanium transistor leakage, dirty heads, and mechanical lube points needing attention. Restorations (belts, recap, tube checks) often yield excellent results. Service manuals (German/English variants) available on HiFi Engine, Elektrotanya, or reel-reel.com; user manuals scarcer but Dutch/related docs help with duoplay/multiplay.