Distributed Audio Power Amp
The Bryston D250Z is a modular multi-channel audio power amplifier delivering 250-watts-per-channel output into 4 ohms. While each of the eight channels can operate completely independently, with its own input, output and level control, each channel is also assigned to one of four zones.
Each zone is comprised of two adjacent channels, and each zone can be remotely muted independently of the other zones. Each channel can select from its own discrete input (RCA or phono jack) or from a common stereo input (stereo bus inputs, also RCA or phono jacks). The inputs are single ended with a gain of 29 dB. There are rear-panel level controls for each channel. Each zone can be muted independently.
The power-up sequence of the 250Z can be controlled from a 4 to 12v (AC or DC) control voltage. The 250Z uses ‘soft start’ power control circuitry to eliminate high inrush currents when A/C power is applied.
Thermal Shutdown and Clipping Protection
The D250Z uses a convection cooling system to keep the amplifier from overheating. Unrestricted airflow across its heat sinks is a must. For this reason do not install anything directly above it.
Thermal shutdown circuitry prevents damage due to overheating. Should thermal shutdown occur, both stereo channels in the affected zone will mute and the channel LEDs will turn red. When the channels have cooled to a safe operating condition the channels will return to normal operation. Persistent thermal shutdown indicates steps need to be taken to increase airflow across the channels heat sink.
Clipping is another safety feature which occurs when the channel output level no longer can follow the level increase at the input (overdriven input condition). When a 250Z channel is driven into clipping, the channel LED will change from green to red then back to green when the level is reduced (will appear to be intermittent or flashing red). Momentary clipping can be tolerated, but it indicates that maximum undistorted power has been surpassed and potential speaker damage may result if overload conditions persist. Any amplifier that is constantly operated into clipping indicates a more powerful amplifier is needed for that application.
Remote power Turn On
When an external 12v control signal is applied between the 2 'In' pins on the connector, the amplifier will power up. When the 250Z has powered up, the incoming 12v is handed to the 'Out' terminals to turn on other equipment.
When in the 'Local' position, the amplifier power-up sequence is initiated by the front panel power switch only. When in the 'External' position, and with the front panel power switch 'Off,' the amplifier will power up when a control voltage of between 4 and 12 volts (AC or DC) is present across the pair of 'In' pins of the Remote Power Turn-On Connector. | 
