ZAPCO Z-SP Super Power Series - Z-150.4 SP

The  Z-SP Super Power Series, which includes the Zapco  Z-150.4 SP 4-channel amplifier with 4x 275 Watt RMS at 2 Ohm,  became  developed from the need to equip vehicles competing in the new category "Street Challenge" or "Street Demo". This  is a big challenge for the components and generates more heat than audiophile listening because they are played at full power, all the time.
Among other things, a completely  new air cooling system in a chassis with internal fins and fans that dissipate heat from the chassis. The fans blow on the fins to push air downwards and the side vents create turbulence that pushes hot air out and cold air in along the entire length of the amplifier. A new aerospace-grade material was chosen to insulate the output transistors, allowing heat to be dissipated from the equipment much faster than standard insulators. 

The result: amplifiers that you can turn up to full volume and play all day long. With a few upgrades in the circuitry, the stages now also have high-pass, low-pass and band-pass crossovers, x10 range switches for precise selection of the crossover frequency, variable sub-sonic filter with band-pass, variable bass boost, variable gain, an additional RCA output and compatibility with a bass remote control.

On most amplifiers, all these preamp controls offer more versatility, but they also rob signal quality. On Zapco's Z-Series SP amplifiers  However, even with crossovers and bass boost, you get a signal-to-noise ratio of over 103 dB, a distortion factor of less than 0.1% and a channel separation of more than 60 dB. In addition, the SP amplifiers receive a 10% increase in performance due to increased thermal efficiency.

• Cooling fan with thermal speed control
• Insulator with 70% less thermal resistance than MICA for faster heat transfer
• Proprietary RCA connectors soldered directly to the circuit board with extra strong coating
• (Zapco design) with 6 ground contacts each for absolutely safe installation
• Symmetrical and differential inputs with one tenth of the normal resistance
• Bass Boost, which disappears from the circuit when set to 0
• Capacitors with lower internal resistance and lower inductance 
• Fine adjustment of the bias voltage in each channel
• An individual plaque with model and serial number makes this amplifier something special

• 4-channel Street Power competition amplifier
• Dual crossovers with wide frequency range and bandpass filtering
• Variable bass boost
• Variable subsonic filter
• ducted air fan cooling system
• Space-Age technology for cooler output devices
• Proprietary gold RCA panel mount connectors
• Remote control for amplification on the dashboard available

• Power @ 4Ω: 4 x 165 Watt RMS 
  
• Power @ 2Ω: 4 x 275 Watt RMS 
  
• Power @ 4Ω bridged: 2 x 550 Watt RMS
  
• THD @ rated power < 0.05%
  
• Signal-to-noise ratio > 104dB
  
• channel separation > 60dB
  
• Frequency response 10Hz to 30.000Hz ±1dB
  
• Input sensitivity .25v to 8v
  
• Dimensions in mm: 241(W) x 62(H) x 479(L)