The Helvia Zeus 4240CA installation power amplifier has four independent channels, each with a line transformer and a choice of operation at 70/100 V constant-voltage line or low impedance of 4–16 Ω. Each channel features a volume control, a rear-panel gain control, and LED VU meter and clip indicators. The HPF has a cutoff frequency of 400 Hz.

The balanced inputs and outputs connect via XLR, while the power outputs use Phoenix (Europlug) connectors. Each channel features power-on muting, a signal limiter, thermal protection, and current limiting. Cooling is provided by a fan whose speed is controlled according to the internal temperature.

• Type: Power amplifier
• Channels: 4
• Power: 240 W per channel at 100 V
• Low-impedance operation: 4–16 Ω
• Class: D
• HPF: 400 Hz, with selectable on/off operation
• Frequency response: 80–20,000 Hz or 400–20,000 Hz
• Damping factor: >300 at 100 Hz
• THD: <0.1% at 1 W and 1 m
• Inputs and outputs: Balanced, with XLR connectors
• Power outputs: Phoenix (Europlug) connectors
• Indicators: LED VU meter and clip indicators per channel
• Protection: Power-on muting, signal limiter, thermal protection, and current limiting per channel
• Cooling system: Fan with speed control based on internal temperature
• Mounting: 19″ rack, 2U
• Width: 484 mm
• Height: 88 mm
• Depth: 400 mm
• Weight: 17 kg