Crown SX-824

The Crown SX-824 (also listed as Crown SX824 or part of the Pro 800 series with SX electronics) is a high-end, solid-state open-reel tape recorder from Crown International (Elkhart, Indiana, USA), produced in the late 1960s to mid-1970s (peak availability around 1970–1977). It belongs to the flagship Pro 800 series (often called the 800 series or "Big Red Monster" for its robust build and occasional red accents in custom variants), where "SX" denotes the basic/simplified electronics package (fixed circuit boards, rear-panel bias adjust, 2-speed equalization, simplified circuitry) compared to the deluxe CX variants (e.g., CX-824 with plug-in modular boards, front bias/EQ, bass/treble, echo/sound-on-sound, full 3-speed EQ).

The "-824" indicates a 2-channel (stereo) configuration with ¼-track (quarter-track/four-track) stereo record/playback. This was a professional/semi-pro deck for audiophiles, broadcast, small studios, or mastering—prized for Crown's exceptional tape handling (no tension arms; torque-controlled reels), rugged overbuilt construction, gentle operation, and warm, dynamic "tape magic" sound (slight high-end contour/bloom for musicality rather than ultra-flat response). Collectors often call it a "holy grail" of vintage decks due to its reliability and sonics. Surviving units are rare, frequently restored (e.g., by specialists like Chuck Ziska), and sell for $3,000–$7,000+ in serviced condition, often in custom walnut cabinets or racks.

Key Technical Specifications 

• Tape Speeds: 3.75 ips and 7.5 ips (standard SX 2-speed equalization; some early/modified units or with optional pulley changes supported 15 ips, but SX-824 typically lacked full 3-speed EQ unlike CX models).

• Frequency Response (±2 dB typical): 30 Hz–20 kHz (or better) at 7.5 ips; 30 Hz–10 kHz at 3.75 ips (respectable for era; slight high-end contour for warmth/bloom on premium tape like Scotch 207/406).

• Signal-to-Noise Ratio: 55–60 dB (overall/record-play; strong for ¼-track stereo, aided by low-noise design).

• Wow & Flutter (RMS wideband): ~0.05–0.09% at 7.5 ips (excellent stability from massive flywheel, hysteresis capstan, and neoprene belt).

• Track Configuration: ¼-track stereo (four-track two-channel; bidirectional for extended play/overdubbing/reserve tracks; some variants like SX-824-P4C added 4-channel playback compatibility for multi-track tapes).

• Heads: 3-head design (erase, record, playback); precision micro-gap permalloy heads with hyperbolic contour, shock-mounted/removable for alignment; off-tape monitoring while recording.

• Reel Sizes: Up to 10.5" NAB professional (HAP adapters standard; supports 2400'+ reels).

• Motors: 3-motor transport (hysteresis synchronous capstan with large flywheel/belt; separate plug-in torque-controlled reel motors—no tension arms; electromagnetic DC braking for smooth ~3-sec stops).

• Timing Accuracy / Speed Stability: ~99.8% (minimal drift; fast wind/rewind ~60 sec for 2400').

• Other Features:SX basic electronics: Fixed boards (simpler than CX plug-ins); rear-panel bias adjust; record mode interlock; 2-speed equalization; mixing inputs (multiple mic/line per channel, unbalanced standard; balanced optional via accessories); dual VU meters; headphone monitoring; source/tape switching; auto-stop; mechanical pushbutton controls (forward/rewind/stop/operate; no full logic memory like 800 series in some descriptions).
  Inputs/Outputs: Mic/line (high impedance or optional balanced); line outputs up to 14V+ (600 ohm balanced/unbalanced).
  THD: <1% at 0 VU (1 kHz); high headroom/low distortion.
  Power: ~140–200W, 117 VAC 60 Hz (50 Hz available).
  

• Dimensions / Weight: ~19" W x 15" H x ~10" D (rack-mountable; detachable transport/electronics); ~48 lbs (sturdy aluminum chassis; some listings note 48–52 lbs).

• Original Price: ~$1,495 (premium pro positioning; comparable to SX-822 at similar pricing, with options pushing higher).

Design and Build Overview

The SX-824 used the Pro 800 transport (logic-controlled pushbuttons in full 800 series, though some brochures show mechanical for SX; no tension arms—torque motor control for precise/pantograph-like tension, straight-line threading for editing). Electromagnetic braking provided gentle, consistent operation. SX electronics were Crown's basic solid-state offering: fixed boards, simplified circuitry, rear bias adjust—reliable and serviceable but lacking CX deluxe features (e.g., front bias/EQ, echo, full 3-speed EQ, plug-in modularity).

Built overbuilt for longevity (aluminum chassis, field-replaceable motors/heads/belts), it prioritized professional reliability—broadcast/TV standard, audiophile mastering—with warm, blooming sound (dynamics/headroom from slight contouring). Compared to CX-824 (deluxe sibling: plug-in boards, front adjustments, echo, often 3-speed EQ, ~$1,995+), the SX-824 was the cost-effective workhorse (simpler but nearly identical core performance/transport).

Today, these are sought-after vintage pieces. Common restoration needs: electrolytic recapping (critical), bearings, relays, head relapping/alignment, belt/pinch roller renewal. Manuals cover Pro 800 series (SX/CX). Crown exited tape production ~1977 for amplifiers.