Crown 712

The Crown 712 is a rare vintage open-reel tape recorder from Crown International (Elkhart, Indiana, USA), produced circa 1963–1964 as part of the early tube-based (valve) 700 series lineup. This transitional series bridged Crown's 1950s consumer-focused machines and the later solid-state professional 700/800 series (introduced mid-1966). The 712 was configured as a half-track stereo (½-track two-channel) deck, providing wider tracks for superior signal-to-noise ratio, dynamics, and headroom in stereo compared to quarter-track formats—making it suitable for high-fidelity home use, small studios, or semi-pro mono/stereo applications where maximum quality per track was prioritized.

This model (alongside siblings: 701 full-track mono, 702 half-track mono, 714/714C four-track stereo) is extremely scarce, with limited surviving examples noted in collector archives and occasional sales. It emphasized Crown's signature overbuilt American engineering: reliable three-motor transport, gentle tape handling via differential-magnetic braking, and warm tube sound with a characteristic slight high-end contour ("tape bloom") for rich, non-flat reproduction.

Key Technical Specifications 

• Tape Speeds: 3.75 ips, 7.5 ips, and 15 ips (three professional speeds for high-fidelity, extended play, or precise timing).

• Frequency Response: 20 Hz to 30 kHz (±2 dB at 15 ips; typical slight high-end bump/contour for enhanced warmth and "bloom" rather than strictly flat response).

• Signal-to-Noise Ratio: Approximately 51–56 dB (e.g., ~56 dB at 15 ips, ~54 dB at 7.5 ips, ~51 dB at 3.75 ips on premium tape; strong for tube-era stereo due to half-track width).

• Track Configuration: Half-track stereo (½-track two-channel record/playback; wider tracks optimize SNR and dynamics on ¼" tape for stereo mastering or hi-fi).

• Heads: 3-head design (erase, record, playback); permalloy composition with precision micro-gap and hyperbolic contour for stable alignment and clean transfer.

• Reel Sizes: Up to 10.5" NAB professional reels (standard for extended stereo recordings; adapters supported).

• Motors: 3-motor transport (hysteresis synchronous capstan drive with flywheel; separate plug-in reel motors; differential-magnetic braking for smooth, padless, gentle stops/starts).

• Timing Accuracy / Wow & Flutter: Speed accuracy ~99.8%; wow & flutter low (~0.1–0.2% range, excellent stability comparable to contemporaries like Ampex or Berlant Concertone).

• Other Features:All-tube electronics (high headroom, warm harmonic character typical of pre-solid-state Crown designs).
  NAB equalization (separate per-speed settings; CCIR optional in variants).
  Separate bass/treble boost controls on both record and playback.
  Inputs: Microphone and phono/line; outputs: Cathode follower.
  Controls: Forward/stop/play/record, thread/idle, rewind, bias lock, equalization (per speed), reel-size switch.
  DC valve filaments for reduced hum/noise.
  Automatic stop, fast rewind (~38–60 sec for typical reels).
  THD: Less than 1.5%.
  

• Weight: Around 40–50 lbs (rugged, overbuilt chassis for low resonance and long-term durability).

• Original Price: Likely $500–$800+ range (premium for early 1960s high-end stereo tube recorder; comparable to contemporaries).

Design and Build Overview

The Crown 712 utilized a robust 3-motor direct-drive transport for precise tension, minimal wow/flutter, and dependable stereo operation—core traits refined in later solid-state models. Tube amplification delivered dynamic, high-headroom performance with signature warmth (slight frequency contouring contributing to a "blooming" or "tape-like" sound). Braking was differential-magnetic for consistent, gentle action without mechanical pads.

Some design elements carried over from earlier "B Deck" predecessors (e.g., potential head alignment quirks in related assemblies, piano-key controls susceptible to long-term wear), but it advanced toward professional-grade capability. The half-track stereo format maximized audio quality for the era's stereo enthusiasts, suiting applications like home mastering or broadcast before quarter-track became dominant for consumer versatility.

Today, the 712 is an ultra-rare collectible, documented primarily through museum archives (e.g., Museum of Magnetic Sound Recording) and collector references. Restoration typically requires electrolytic recapping, tube replacement/sourcing, motor bearing service, head relapping/alignment, and control cleaning (piano keys often fail over decades). It represents a key chapter in Crown's evolution from tube to solid-state tape production (ended ~1977).