Zapco - ST-4B - Class AB, 4-Ch Power 2Ω: 4 x 90W, 4Ω: 4 x 65W

• Model: ST-4B
• Channels: 4 (full-range, Class AB)
• Power Output:
 • 90 W × 4 @ 2 Ω
 • 65 W × 4 @ 4 Ω
 • Bridged: 180 W × 2 @ 4 Ω
• Total Harmonic Distortion (THD): < 0.1% at rated power
• Signal-to-Noise Ratio: > 100 dB
• Frequency Response: 20 Hz – 50,000 Hz
• Input Sensitivity: 0.2 V – 6 V (adjustable)
• Protection Features: Over-current, over-temperature, DC offset, short circuit
• Construction: Compact, thermally efficient design with integrated heatsinks
• Dimensions: Approx. 160 × 115 × 45 mm
• Use Case: Ideal for driving multiple speakers or as a mid/high channel in multi-amp systems