Praesideo product line provides four types of power amplifier equipment. Different types of amplifiers have different number of channels: 1, 2, 4, or 8. The overall rated power of all amplifiers is 500 W. Power amplifier can be set to 100 V, 70 V and 50 V output Settings. They have the function of ground short circuit and short circuit detection, and generate the pilot tone for monitoring. Annotated model suffix (-eu, -cn... ) represents the local version of these amplifiers. The amplifiers are identical except for certification, power lines and origin. The basic functional power amplifier receives input signals through the network bus. In addition, they have two auxiliary audio inputs (lbb4428/00-cn has four) that can be used for local audio. Their 8-way control inputs are freely programmed for multiple system operations and can be assigned different priorities. Each control input can monitor the connected circuit to determine whether there is an open circuit and a short circuit. Control output can be freely programmed for operations related to failures and calls. 2 x 16 character display and rotate button to realize local state query. When the audio monitoring mode is activated, the display displays the VU meter reading. You can also use headphones to listen for audio. These amplifiers have self-monitoring capabilities and can continuously report their status to the network controller. They support separate branches and redundant loop wiring. In addition, these amplifiers also have a switching function for switching standby power amplifiers. The amplifier has a built-in switching relay. These amplifiers also have 48 VDC backup power inputs. Digital audio processing function can handle three parameter equalization and two shelf equalization on each channel, as well as configurable audio delay function. Controls and lamp, 2 x 16 characters status LCD display, knob/button controls, power switch, PRS ‑ xPxxx interconnection, the ac power input, the voltage selector backup battery input, two systems network, two lines of mic/line input (LBB 4428/00 has four road input), you can choose to 100 V, 70 V or 50 V output (each channel), fixed 50 V output, eight-way, programmable control inputs Control output (for each amplifier channel) • headphone output • standby amplifier connection (for each amplifier channel)