The Bang & Olufsen Synchrobox 4001 is a rare and highly collectible vintage accessory designed to synchronize audio playback with slide projectors. Developed in the 1960s, this unit represents an early and innovative solution for creating fully synchronized audiovisual presentations.
Using a signal detection system, the Synchrobox identifies synchronization tones recorded on tape and automatically triggers a connected slide projector. This allows seamless transitions between slides, perfectly timed with the audio.
Ideal for collectors, restorers, and vintage Bang & Olufsen enthusiasts, the Synchrobox 4001 is both a functional device and a unique piece of B&O history.
Original Bang & Olufsen vintage accessory
Synchronizes tape audio with slide projection
Automatic slide change trigger via audio signal
Built with transistor-based electronics (5 transistors)
Compact and durable metal housing
Manual test button and sensitivity adjustment
Designed for use with Beocord tape recorders
The B&O Synchrobox 4001 detects specific tones recorded on a tape. When a tone is detected, the unit sends an electrical impulse to a connected slide projector, advancing the slide automatically.
This system was widely used for:
Educational presentations
Business demonstrations
Audio-guided photo slideshows
The Bang & Olufsen Synchrobox 4001 is a rare example of early multimedia technology. It reflects B&O’s forward-thinking design and engineering, long before digital synchronization existed.
Perfect for:
Bang & Olufsen collectors
Vintage audio enthusiasts
Restoration projects
Display or functional use
Used condition
Model: Synchrobox 4001
Manufacturer: Bang & Olufsen (Denmark)
Type: Audio-trigger synchronization unit
Transistors: 5
Power Supply: 4.5V DC (3 × 1.5V batteries)
Input: Audio signal from tape recorder
Output: Trigger signal for slide projector
Controls:
On/Off switch
Sensitivity adjustment
Test button
Cabinet: Metal
Dimensions: 167 × 41 × 84 mm
Collectible items
Collectible items
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