Philips N4504

he Philips N4504 (including variants like N4504/00 or rebranded as Maestro 4504 in some markets) is a mid-1970s consumer stereo reel-to-reel tape deck, produced approximately 1974–1978 (manufactured primarily in Austria by Philips Österreich). It was a mid-range model in Philips' N45xx solid-state hi-fi series, serving as the deck-only version (no built-in power amplifier or speakers) of models like the N4510/N4512. This allowed direct integration with external hi-fi amplifiers or Philips' MFB active speakers for full stereo reproduction.

The N4504 featured a three-motor chassis (shared with higher-end N44xx/N45xx contemporaries like N4416, N4418, N4520), providing superior tape handling and stability compared to single-motor designs. It was a 4-track (quarter-track) stereo deck with 3-head configuration (separate record, playback, and erase heads for off-tape monitoring), two speeds, and solid hi-fi performance suitable for serious home recording and playback.

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 — Two speeds:3¾ ips (9.5 cm/s)
  7½ ips (19 cm/s) (No 1⅞ ips; focused on higher-fidelity recording/playback.)
  

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

• Frequency Response (approximate, typical tolerances; varies by tape/condition):At 7½ ips: 40 Hz – 18,000 Hz (or up to 20,000 Hz in some claims)
  At 3¾ ips: 40 Hz – 15,000 Hz Respectable hi-fi extension for mid-range consumer stereo.
  

• Wow & Flutter — Approximately 0.15% at 7½ ips; <0.2% at 3¾ ips (excellent stability from three-motor drive).

• Signal-to-Noise Ratio — Around 50–55 dB (typical for transistor design with low-noise tape).

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

• Drive System — Three DC motors (1 × capstan + 2 × reel motors); belt drive to capstan/flywheel; idler tires/clutches; electronic or mechanical tension control; fast wind/rewind; precise braking.

• Electronics — Fully transistorized; printed circuit board amplifier (deck-only—no integrated power amp; line-level outputs for external amplification).

• Inputs —Microphone: low-level (~0.2 mV / >2 kΩ; stereo pair possible).
  Line/radio/tuner/phono: standard line level (~100–200 mV).
  DIN-style connectors standard.
  

• Outputs —Line out: ~1 V / 50 kΩ.
  Headphones (monitor).
  No built-in speakers or power amp (deck version).
  

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

• Power — AC mains (multi-voltage switchable, e.g., 110–240 V); consumption ~40–60 W.

• Build & Dimensions — Tabletop case (often wood/teak or silver finish); approx. 480 × 330 × 130 mm (18.9 × 13 × 5.1 inches); weight ≈10–12 kg.

• Manufacturing — Primarily Austria (Philips Österreich).

Performance & Legacy Context

The N4504 was appreciated as a reliable, high-quality deck for external hi-fi systems—offering three-motor stability (smoother transport and better wow/flutter control), 3-head monitoring (real-time off-tape listening), and strong performance at 7½ ips. As a pure deck (no built-in amp/speakers), it integrated seamlessly into existing setups, delivering clear stereo imaging, good dynamics, and low noise when aligned and serviced. It was a step up from single-motor models but below auto-reverse flagships like the N4450.

Common issues today: Belt/idler goo (multiple belts—main drive, counter, etc.—need full replacement kits), dried electrolytic capacitors, transistor aging, dirty heads (3-head alignment critical), worn idler tires/clutches, and mechanical adjustments. Restorations are common and effective—many enthusiasts report excellent post-service performance. Service/user manuals available (HiFi Engine, Elektrotanya—includes schematics and alignment).

Compared to siblings:

• N4502 — Very similar (often considered the same deck with minor regional differences).

• N4510/N4512 — Close relatives with slight variations (e.g., N4512 sometimes listed with belts prone to wear).

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