Philips Pro 36

The Philips Pro 36 (also known as Pro' 36, LDB0002 /01, or sometimes marketed as Pro 36 Vertical) is a late 1960s semi-professional stereo reel-to-reel tape recorder, produced approximately 1967–1972 (primarily manufactured in Austria by Philips Österreich). It was the mid-range model in Philips' professional tape recorder lineup at the time, positioned above the entry-level Pro 12 (cheaper, smaller) and below higher-end broadcast machines. The Pro 36 was designed for semi-professional applications such as small studios, educational institutions, churches, or advanced home use, offering professional features like three heads, three motors, separate record and playback amplifiers, and vertical operation (a distinctive tall, upright design that saved desk space).

It was a 2-track (half-track) stereo recorder (some configurations allowed 4-track playback of consumer tapes), with a focus on reliability, sound quality, and flexibility for multiplay/echo effects.

Key Technical Specifications

• Recording/Playback System — 2-track (half-track) stereo/mono compatible; records and plays stereo on tracks 1-2 forward (no reverse pair without manual flip); mono compatible; sound-on-sound/multiplay overdub facilities via separate heads/amplifiers; echo recording possible; no auto-reverse.

• Tape Speeds — Two professional speeds:7½ ips (19.05 cm/s)
  15 ips (38.1 cm/s) (No consumer speeds like 3¾ or 1⅞ ips; optimized for broadcast/studio fidelity.)
  

• Reel Size — Up to 10.5 inches (26.5 cm) NAB hubs (professional large reels for extended playtime; also supports 7" cine reels).

• Frequency Response (approximate, typical tolerances; varies by tape/condition):At 15 ips: 30 Hz – 18,000 Hz (±2 dB)
  At 7½ ips: 30 Hz – 15,000 Hz (±2 dB) Broadcast-grade extension for the era.
  

• Wow & Flutter —At 15 ips: <0.07%
  At 7½ ips: <0.1% Excellent stability from three-motor drive.
  

• Signal-to-Noise Ratio — Approximately 55–60 dB (strong for semi-pro transistor era).

• Heads — 3 heads: separate record, playback, and erase (permalloy; enables before/after monitoring, echo, multiplay).

• Drive System — Three motors (capstan + two reel motors); belt drive to capstan/flywheel; idler tires/clutches; mechanical brakes; fast wind/rewind; precise tension and braking.

• Electronics — Fully transistorized; printed circuit board amplifier; separate record and playback amplifiers (allows simultaneous record/playback monitoring, echo, and sound-on-sound).

• Amplification & Speakers — Built-in stereo amplifiers; internal loudspeaker(s) (control amp with speaker: ~500 mW–1 W); output power modest for monitoring.

• Inputs —2 × microphone: 1 mV, 50–200 Ω
  Line: 150 mV, 1.5 MΩ
  DIN-style connectors standard.
  

• Outputs —Line-out: 0.775 V, 10 kΩ
  Headphones: max. 1 V, 400 Ω
  DIN-style.
  

• Features —Twin separate level meters (one per channel; active for record/playback).
  Before/after tape monitoring.
  Echo/multiplay effects.
  Pilot tone head (in some configs for synchronization).
  Pause function.
  Vertical operation (tall upright design; saves desk space).
  Portable/semi-portable with metal case and handle.
  

• Power — AC mains (110–120 V / 220–240 V switchable); consumption ~80–100 W.

• Build & Dimensions — Metal case with handle (silver/metal finish); vertical design approx. 520 × 250 × 600 mm (20.5 × 9.8 × 23.6 inches tall); weight ~23–25 kg (robust semi-pro construction).

• Manufacturing — Primarily Austria (Philips Österreich).

Performance & Legacy Context

The Pro 36 was highly regarded in its time for offering professional features (three heads, three motors, separate amplifiers for monitoring/echo) at a more accessible price than Philips' full broadcast line (e.g., Pro 36 was roughly 1/3 the cost of the next model up). It excelled for semi-pro tasks (small studios, education, churches, or advanced home mastering) at 15 ips, delivering clear, balanced sound with excellent dynamics and low noise. The vertical design was innovative for space-saving in studios or home setups.

Compared to siblings:

• Pro 12 — Entry-level semi-pro: 2-track, 7½/15 ips, three heads/motors but smaller/cheaper.

• Pro 36 — Mid-range with vertical design, larger reels, and refinements.

• N44xx/N45xx consumer series — Later domestic hi-fi line (e.g., N4408/N4520) with more consumer features but less pro build.

• N4520/N4522 — Much later 1970s flagships (quartz PLL, 10.5" NAB focus, glass-ferrite heads).

Common issues today: Belt/idler degradation (goo/melting—kits needed), dried electrolytic capacitors, transistor aging, dirty heads (3-head alignment critical), worn idler tires/clutches, and mechanical wear on vertical transport. Restorations are common—many units revive well for vintage semi-pro sound. Service/user manuals available (HiFi Engine, Elektrotanya—schematics and alignment; some English versions exist).