Zapco - ST-64D SQ MINI - Class D, 4-Ch, optional HD-BT Power 2Ω: 4 x 75W, 4Ω: 4 x 50W

The Zapco ST-64D SQ MINI is a compact Class D 4-channel amplifier designed for sound quality enthusiasts who demand high fidelity in a small form factor. Delivering 75 watts RMS per channel at 2 ohms, it provides powerful and clean output ideal for full-range or active speaker setups. Featuring optional HD-BT Bluetooth streaming, flexible crossover control, and ultra-low distortion, the ST-64D SQ MINI brings Zapco’s renowned analog warmth and precision to modern compact installations.

• Model: ST-64D SQ MINI
• Type: Compact Class D 4-Channel Full-Range Amplifier
• Power Output (RMS):
 • 4 Ω Stereo: 4 × 50 W
 • 2 Ω Stereo: 4 × 75 W
 • 4 Ω Bridged: 2 × 150 W
• Amplifier Topology: High-efficiency full-range Class D design
• Frequency Response: 10 Hz – 30 kHz (±1 dB)
• Signal-to-Noise Ratio: > 95 dB
• THD + N: < 0.05% at rated power
• Input Sensitivity: 0.2 V – 8 V (variable)
• Input Type: High-level or RCA (auto-detect)
• Input Impedance: 10 kΩ (unbalanced RCA)
• Crossover Controls:
 • High-Pass Filter (HPF): 20 Hz – 4 kHz (12 dB/octave)
 • Low-Pass Filter (LPF): 50 Hz – 500 Hz (12 dB/octave)
 • Band-pass capable through filter combination
• Bass Boost: 0 – 12 dB @ 45 Hz (adjustable)
• Optional Module: HD-BT add-on for aptX HD high-resolution Bluetooth streaming
• Cooling System: Passive aluminum heatsink (fanless thermal design)
• Protection Circuits:
 • Thermal overload
 • Short circuit
 • DC offset
 • Over/under voltage
• Fuse Rating: 2 × 25 A
• Power Supply: Regulated MOSFET PWM
• Dimensions: 7.9″ (L) × 6.5″ (W) × 2.0″ (H)
• Weight: Approx. 4.6 lb (2.1 kg)
• Warranty: Standard manufacturer warranty