• Amplifier design: Class AB High Bias
• Channels: 4
• Power (4Ω): 150W × 4
• Power (2Ω): 240W × 4
• Bridged power (4Ω): 480W × 2
  
• Minimum speaker load: 2Ω (4Ω bridged)
  
• Input sensitivity: 5V to 900mV
  
• Input impedance @ 1 kHz: 10 kΩ
  
• Frequency response (-0.5 dB): 5 Hz – 100 kHz
  
• THD: 0.0035%
  
• Working voltage: 10–16V
  
• Filters / active crossover: No
  
• Fuse: 2 × 50A
  
• Protection: Thermal and short circuit
  
• Dimensions: 360 × 215 × 54 mm
  
• Weight: 4.5 kg

• Class AB 4-channel amplifier designed around neutral / transparent sound
• Individually balanced channels for matched output
• Dual symmetrical power supply with shielded transformers and large capacitors
  
• No built-in filters / pass-throughs — designed to be paired with an external DSP
  
• 24-karat gold-plated terminals
  
• Extended frequency range (5 Hz – 100 kHz) for high-resolution playback capability

• DSP-based builds where crossovers/EQ are handled externally (because the amp has no onboard filters)
• SQ-focused installs wanting a neutral amp platform
• Running a full active front stage + rear fill, or bridging for higher power where appropriate (bridge mode stable to 4Ω)

We like amps like the 7A4 because it doesn’t try to do everything—no built-in crossovers, no processing layers, no extra “features” in the signal path. It’s made to be used with a proper DSP and good install practices, and the spec set (very wide bandwidth, low THD, strong SNR, stable low impedance) lines up with what people chasing clean SQ actually care about.