Specifications GSQ-5200 (Equalizer) (real-world typical data) Based on listings and service documentation: Type: 12-band stereo graphic equalizer Frequency range: ~16 Hz – 32 kHz Control range: ±12 dB Bands: 12 sliders per channel Signal-to-noise ratio: ~113 dB (high quality for its class) THD: ~0.003% Connections: RCA line in/out + tape loop Power: 220–240V AC Format: 43 cm hi-fi rack unit (standard full size) In simple terms: very good quality analog equalizer for its era GST-5200 (Tuner) Type: AM/FM stereo tuner Role: radio receiver for the system Typical features: Analog tuning scale / digital display (varies by version) Station memory presets (system dependent) Signal strength indicator Build: full-width hi-fi unit Era: ~1983–1987 (same family as GSQ-5200) Function: “radio source” of the system