CD-4 kvadro demodulátor Dual CD 40

Here’s the English version of the technical specifications for the DUAL CD 40, a demodulator designed for playing quadraphonic LP records using the CD-4 system:
📻 General Information
Manufacturer: Dual, Gebr. Steidinger, St. Georgen/Schwarzwald, Germany
Production Years: 1974–1978
Device Type: CD-4 demodulator (Four-channel record demodulator)
Purpose: Converts signals from CD-4 quadraphonic LP records into four discrete audio channels
⚙️ Technical Specifications
Power Supply: AC – 110 V / 220 V
Dimensions: 200 × 108 × 335 mm
Weight: 2.7 kg
Transistors: 33
Integrated Circuits (ICs): 6
Output Type: For headphones or amplifier
Cabinet Material: Wood (walnut finish)
Features:
Mode switch: CD-4 quadraphonic / stereo
Built-in preamplifier with RIAA equalization
Connects between turntable (with magnetic cartridge) and quadraphonic amplifier
📈 Performance Parameters (Typical Values)
Frequency Response: 5 Hz – 20 kHz ± 0.5 dB
Signal-to-Noise Ratio: 100 dB
Dynamic Range: 95 dB
Channel Separation (1 kHz): 94 dB
Total Harmonic Distortion (1 kHz): 0.003%
Wow & Flutter: 0.001%
Output Voltage: 2 V
Power Consumption: 25 W
This demodulator was essential for decoding the high-frequency carrier signal used in the CD-4 system to separate the rear channels of quadraphonic sound. If you'd like, I can also help with connection diagrams or the historical background of the CD-4 format