Philips N4450

The Philips N4450 (including variants like N4450/00, /15, /19, /43, or rebranded as Maestro 4450 in some markets) is a mid-1970s flagship consumer stereo reel-to-reel tape recorder/amplifier, produced approximately 1971–1977 (primarily manufactured in Austria by Philips Österreich). It was one of the most advanced models in Philips' N44xx solid-state hi-fi series, often promoted as a "home studio" unit with automatic reverse (auto-reverse) capability, full DIN 45500 hi-fi compliance, and a built-in stereo power amplifier. This made it a rare and desirable open-reel deck for serious home recording, music enthusiasts, and semi-professional use in the era when cassettes were rising but open-reel still dominated high-fidelity.

The standout features were auto-reverse (automatic direction change at tape end, both record and playback), 6-head configuration (dual sets for forward/reverse), three-motor drive, large 10.5-inch reel support, and integrated 20 W stereo amplification with speakers—allowing direct, high-quality listening without external gear.

Key Technical Specifications

• Recording/Playback System — 4-track (quarter-track), 2-channel stereo/mono compatible; auto-reverse (automatic switching at tape end in both record and playback modes; manual reverse also possible); records and plays stereo on tracks 1-4 forward and 3-2 reverse without manual flip; mono compatible; sound-on-sound/multiplay overdub facilities.

• 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 10.5 inches (26.5 cm) maximum diameter (NAB hubs; supports large professional reels for extended playtime).

• Frequency Response (approximate, within DIN tolerances; varies by tape/condition):At 7½ ips: 40 Hz – 20,000 Hz (some sources claim 35–25,000 Hz)
  At 3¾ ips: 40 Hz – 15,000–18,000 Hz
  At 1⅞ ips: 60 Hz – 8,000–11,000 Hz Excellent hi-fi extension at higher speeds.
  

• Wow & Flutter — 0.15% at 7½ ips (very low; benefits from three-motor and Hall-effect capstan servo).

• Signal-to-Noise Ratio — >50 dB (some sources >48–56 dB; strong for the era with low-noise tape).

• Total Harmonic Distortion — <1%.

• Heads — 6 heads (2 × playback, 2 × record, 2 × erase; long-life permalloy; dual sets for forward/reverse auto-reverse without head switching issues).

• Drive System — Three motors (1 × Hall-effect servo capstan motor + 2 × DC reel motors); constant hydraulic tape tension stabilizers; electronic or advanced mechanical tension control; fast wind/rewind (within ~300 seconds for full 10.5" reel); precise braking.

• Electronics — Fully transistorized; printed circuit board amplifier; relay-powered in some aspects.

• Amplification & Speakers — Built-in stereo power amplifier; dual internal loudspeakers; output power 20 watts total (or 2 × 10 W; room-filling capability).

• Inputs —Microphone: 0.2 mV / >2 kΩ (stereo pair or mono).
  Line/radio/tuner: 100 mV / 100 kΩ.
  Phono MM: 1.5 mV / 47 kΩ.
  Phono crystal: 100 mV / 1 MΩ.
  DIN-style connectors standard.
  

• Outputs —Line out: 1 V / 50 kΩ.
  Monitor: 1 V / 50 kΩ.
  Headphones.
  External speakers.
  DIN-style.
  

• Features —Twin illuminated VU meters (needle type; active for record/playback).
  Auto-reverse with manual override.
  Separate bass/treble tone controls.
  Input mixing.
  4-digit tape counter.
  Off-tape monitoring (before/after tape).
  Pause function.
  Optional cable remote control (N6719).
  Vertical or horizontal operation.
  Portable/tabletop design with lid/handle.
  

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

• Build & Dimensions — Tabletop case (often wood/teak finish); approx. 520 × 500 × 210 mm (20.5 × 19.7 × 8.3 inches); weight ≈20 kg (heavy due to motors, heads, amp, and large-reel capability).

• Manufacturing — Primarily Austria (Philips Österreich).

Performance & Legacy Context

The N4450 was Philips' "dream" consumer open-reel in the mid-1970s—celebrated for auto-reverse (rare and convenient at the time), 10.5" reel support (long play sessions), 6-head dual-direction setup (true bidirectional stereo without compromises), three-motor/Hall servo stability, and integrated 20 W stereo amp. It delivered outstanding clarity, dynamics, and wide bandwidth at 7½ ips, often rivaling pro decks for home use. The auto-reverse mechanism (with hydraulic tension and precise switching) was a highlight, though it added mechanical complexity.

Common issues today: Belt/idler goo (multiple belts—full kits required), dried electrolytic capacitors, transistor aging, dirty heads (6-head alignment critical), worn idler tires/clutches, capstan motor (Hall-effect) failures, and relay/logic issues. Restorations are challenging but rewarding—many collectors praise serviced examples for exceptional sound. Service/user manuals available (HiFi Engine, Elektrotanya, Retronik—full schematics, alignment, bias procedures).

Compared to siblings:

• N4422 — Similar flagship but no auto-reverse, smaller reels (7").

• N4418 — Three motors/heads but mechanical controls and no auto-reverse.

• N4450 — Pinnacle with auto-reverse, 10.5" reels, and premium execution.