Pioneer - RG-9 - RG dynamic processor Signal processor

This is one of Pioneer's unique products - the Pioneer RG-9 is an analog dynamic audio processor produced during the classic Hi-Fi era. It is designed to expand and control the dynamic range of audio signals, making music sound more lively and expressive without conventional compression.

Purpose
Dynamic range expander / processor
Enhances perceived dynamics by:
Raising low-level signals
Controlling high-level peaks
Intended to restore dynamics lost in recordings or playback chains

Signal Path

Line-level audio device
Installed between preamplifier and power amplifier (or via tape loop)
Compatible with standard Hi-Fi components

Key Functions
Dynamic Expansion Control
Adjustable expansion level
Attack / Release Control
Controls how fast the processor responds to signal changes

Gain Control
Maintains proper output level after processing
Bypass / Defeat Mode
Allows direct comparison with unprocessed signal

Technical Specifications (typical)
Frequency response: Approx. 20 Hz – 20 kHz
Total Harmonic Distortion (THD): ~0.05% at 1 kHz
Input level: Line level (approx. 300 mV nominal)
Output level: Line level (up to ~1 V)
Signal-to-noise ratio: High for analog Hi-Fi equipment of its era
Power supply: AC mains (region-specific voltage)


Physical Characteristics:
Dimensions: Approx. 420 mm (W) × 99 mm (H) × 336 mm (D)
Weight: Approx. 4.4 kg
Front panel: Aluminum shampagne colour with rotary knobs and indicator LEDs

Typical Use Cases
Vintage Hi-Fi systems
Improving dynamics of:
FM radio broadcasts
Vinyl records
Cassette tapes

Listening environments where recordings sound flat or compressed

Summary

The Pioneer RG-9 is a dynamic expander, not an equalizer or amplifier
Designed to enhance musical realism and punch fully analog, low-distortion Hi-Fi component
Best used subtly for natural sound improvement

NB! See photos for physical condition (there some small scratches and small damages from use or transportation. It has no impact on sound quality.