Philips N4506

The Philips N4506 (including variants like N4506/00, /15, or nicknamed "Magno Control" in collector circles) is a mid-to-late 1970s flagship consumer stereo reel-to-reel tape recorder, produced approximately 1976–1980 (manufactured primarily in Austria by Philips Österreich). It was one of the highest-end models in Philips' N45xx solid-state hi-fi series, often positioned as a "home studio" or premium hi-fi deck with exceptional performance, wide frequency response, low noise, and advanced features like off-tape monitoring and three-motor drive. This model emphasized high-fidelity recording and playback, with DIN 45500 hi-fi compliance in mind (using low-noise tape), and included a built-in stereo preamp (some versions with full amplifier capabilities for direct speaker drive or external hi-fi integration).

It was a 4-track (quarter-track) stereo machine with true stereo recording and playback in both directions, 3-head configuration, and a focus on audio quality over gimmicks like auto-reverse (unlike the N4450).

Key Technical Specifications

• Recording/Playback System — 4-track (quarter-track), 2-channel stereo/mono compatible; records and plays stereo on tracks 1-4 forward and 3-2 reverse (manual tape flip required for second pair); mono compatible; sound-on-sound/multiplay overdub facilities; no auto-reverse.

• Tape Speeds — Three speeds:1⅞ ips (4.75 cm/s)
  3¾ ips (9.5 cm/s)
  7½ ips (19 cm/s)
  

• Reel Size — Up to 7 inches (18 cm) maximum diameter.

• Frequency Response (approximate, within ~3 dB tolerances; varies by tape/condition):At 7½ ips: 35 Hz – 25,000 Hz (some sources: up to 26 kHz)
  At 3¾ ips: 35 Hz – 19,000 Hz
  At 1⅞ ips: 35 Hz – 11,000 Hz Outstanding extension for a consumer deck—among the widest in Philips' lineup.
  

• Wow & Flutter — <0.1% at 7½ ips; <0.15% at 3¾ ips; <0.3% at 1⅞ ips (excellent from three-motor design).

• Signal-to-Noise Ratio — >56–60 dB (often cited as better than 60 dB at 7½ ips with low-noise tape; very strong for the era).

• Heads — 3 heads: separate record, playback, and erase (permalloy construction; enables real-time off-tape monitoring/A-B comparison).

• Drive System — Three motors (1 × capstan + 2 × reel motors); belt/idler drive to capstan; electronic or advanced mechanical tension control; fast wind/rewind (variable speed in some modes; <180 seconds for 540 m LP tape on 7" reel); precise braking.

• Electronics — Fully transistorized; printed circuit board amplifier; some versions include integrated preamp with mixing/attenuators for multiple inputs.

• Amplification & Speakers — Built-in stereo preamp (line-level outputs); some configurations allow direct drive to external speakers or Philips MFB systems (output ~few watts per channel for monitoring; not a full integrated amp like N4450).

• Inputs —Microphone: ~0.2 mV / >2 kΩ (stereo pair possible).
  Line/radio/phono/tuner/aux: ~100 mV / 100 kΩ.
  DIN-style connectors standard (often with RCA options in export variants).
  

• Outputs —Line out: ~1 V / 50 kΩ.
  Headphones (monitor).
  External speakers or amp.
  DIN-style.
  

• Features —Twin illuminated VU meters (needle type; active for record/playback).
  Mechanical or semi-electronic push-button transport controls.
  Separate tone controls (bass/treble).
  Input mixing/attenuators.
  4-digit tape counter.
  Off-tape monitoring (before/after tape).
  Pause function.
  Portable/tabletop design with lid/handle; vertical/horizontal orientation.
  

• Power — AC mains (220–240 V standard; multi-voltage variants); consumption ≈35–120 W.

• Build & Dimensions — Tabletop case (often wood/teak or black/silver finish); approx. 535–557 × 425–437 × 205–210 mm (21 × 16.7 × 8.1 inches); weight ≈10–14 kg (varies by configuration).

• Manufacturing — Primarily Austria (Philips Österreich).

Performance & Legacy Context

The N4506 was Philips' premium open-reel effort in the late 1970s—lauded for its exceptionally wide frequency response (up to 25–26 kHz at 7½ ips), very low wow/flutter from three motors, high S/N ratio (>60 dB in optimal conditions), and 3-head monitoring for accurate recording. It delivered superb stereo imaging, dynamics, and clarity, often compared favorably to contemporary high-end Japanese or Swiss decks. The built-in preamp and versatile inputs made it flexible for hi-fi integration, though it lacked auto-reverse or larger reels (unlike N4450).

Common issues today: Belt/idler goo (multiple belts—main drive, counter, etc.—need full replacement), dried electrolytic capacitors, transistor aging, dirty heads (3-head alignment critical), worn idler tires/clutches, and occasional power/logic faults. Restorations are popular and yield outstanding results—many collectors describe serviced units as "underrated gems" with excellent sound. Service/user manuals widely available (HiFi Engine, Elektrotanya, Internet Archive—full schematics, alignment, bias info).

Compared to siblings:

• N4502/N4504 — Similar deck-only models (often very close mechanically/electronically; N4506 sometimes seen as an upgraded or variant with wider response).

• N4520/N4522 — Later quartz-PLL flagships with 10.5" reels and even higher specs.

• N4418/N4422 — Earlier three-motor contemporaries with similar heads/speeds but less refined response.