JBL SA550 Classic

• Advanced integrated amplifier in classic design
  
• Bluetooth input with Hi-res AptX®Adaptive technology
  
• Walnut veneer side panels to match JBL Classic and Studio Monitor loudspeakers
  
• 3 digital inputs with Coax and Toslink connectors
  
• High-resolution DAC with ESS ES9038K2M DAC chip
  
• 4 analog inputs including MM phono stage
  
• Class G amplifier topology for ultra-low distortion
  
• Output power 90 W per channel into 8O, 150 W into 4O
  

The JBL SA550 Classic is inspired by the classic 1960s JBL SA600 amplifier, with retro styling and walnut veneer side panels externally matching JBL Classic and Studio Monitor loudspeakers. Internally, the JBL SA550 is a music system for the modern era with an advanced amplifier topology with high output power, inventive efficiency, and fine noise control for captivating musicality and effortless performance. Connect your smartphone or tablet to the SA550 via Bluetooth and enjoy instant high-performance music from all your daily music services and libraries. The JBL SA550 Classic features the latest Bluetooth AptX®Adaptive technology for Hi-Res audio via Bluetooth and low latency to ensure audio is synced with video.

The advanced amplifier topology in the JBL SA550 Classic is called Class G. Class G uses multiple power supplies, while all other amplifiers use only one. The first power supply provides the amplifier with sufficient power to deliver 10 watts per channel, which is not much... but this small amplifier includes a large heatsink that keeps the amplifier stable up to 90 watts per channel. This allows the first 10 watts to be delivered in a topology known as Class A, which is usually not very efficient. The advantage is that no output stage components need to be switched on and off into the music signal, as is usually the case with Class AB or Class D amplifiers. The result is vanishingly low noise and the purest sound, preserving all micro-dynamics and detail.

Of course, 10 watts is not much, so the SA550 can deliver much more. It can deliver a maximum continuous output of 150 watts per channel by using a second power supply with a much higher voltage, and this is where the amplification in the SA550 is incredibly inventive. If this second power supply were simply switched on when needed, unpleasant distortion would occur, including harmonics – very unpleasant. Therefore, the SA550 has a series of high-speed "lifters" that gradually raise the power delivered to the amplifier, follow the music signal, and maintain a 5-volt headroom. In this way, the advantages of Class G amplification can be utilized while eliminating the disadvantages and effortlessly powering any loudspeaker system.