Turn-On Modes

The SI-245 draws more current than a preamplifier’s switched AC outlet can safe- ly supply. Also, your preamplifier may "thump" at dangerous volumes if the amplifier is already on when the preamp turns on. It is usually best to turn the amplifier on only when it is needed. The Turn-On Mode selector switch gives you three options for turning the SI-245 on and off.

Constant - The auto turn-on circuitry is off. The front panel master power switch operates the amplifier. In is "On", out is "Off".

Audio Sense - The master switch on the front panel must be in the "On" position. The amplifier is off when there is no audio signal present at either the left or the right input, but the sensing circuitry is on. The turn-on sensing circuitry looks for a tiny amount of audio signal present at any of the audio inputs. If it detects a sig- nal, the amplifier is turned on. Once the audio signal stops, the sensing circuit waits three minutes, then turns the amplifier off.

3-30 Volt AC/DC Opto-Isolated Voltage Trigger - The master switch on the front panel must be in the "On" position. The amplifier is off when there is no 3-30V AC or DC volt- age detected at the trigger input. Once the sensing circuitry detects a voltage and a line- level audio signal is detected at the input, the amplifier is turned on. Once the voltage stops, the sensing circuit instantly turns the amplifier off. Voltage triggers can be supplied by Niles automated switchers, some video projectors, some surround sound processors, or something as simple as a 16 volt AC wall adapter (Niles XF00008) plugged into the switched outlet of your stereo receiver. DO NOT USE A DC WALL ADAPTER. The long discharge time of the DC adapter’s filter capacitor will delay the turn-off of the amplifier.

If you are using a wall adapter or external power supply to provide the trigger, it doesn't have to be very large (a minimum current capability of 2.5 milliamps for a 3 volt trigger increasing up to a minimum of 38 milliamps for a 30 volt trigger).

INSTALLATION CONSIDERATIONS

SI-245 specifications

Niles Audio SI-245 is a powerful and versatile amplifier specifically designed for custom audio installations, catering to both residential and commercial environments. Known for its impressive performance and reliability, the SI-245 enhances the listening experience by delivering high-quality sound across multiple channels. With a maximum output of 240 watts per channel at 4 ohms, it effectively drives a variety of speaker types while maintaining clarity and detail at all volume levels.

One of the standout features of the Niles SI-245 is its robust construction. Built with high-grade components, it ensures durability and longevity, making it an excellent choice for long-term installations. The amplifier is designed to provide consistent performance under load, which is crucial for maintaining audio fidelity in larger spaces or during extended play sessions.

The SI-245 integrates advanced technologies that contribute to its exceptional sound quality. It employs efficient Class AB amplification, which combines the advantages of both Class A and Class B topologies, resulting in lower distortion and improved thermal performance. This design allows the amplifier to operate cooler, reducing the risk of overheating during heavy use.

Another notable characteristic of the SI-245 is its sophisticated circuitry and signal processing capabilities. The amplifier features two channels, enabling it to support stereo configurations or multi-room setups with ease. The independent volume controls for each channel provide flexibility in adjusting sound levels according to personal preferences or room acoustics, ensuring an optimal listening experience no matter the environment.

The Niles SI-245 also includes various connectivity options, enhancing its compatibility with different audio sources. It features RCA inputs for line-level signals and binding post outputs that accommodate a wide array of speaker connections. Additionally, it comes with a 12V trigger input for seamless integration with other components in the audio system, allowing for easy automation and control.

Overall, the Niles Audio SI-245 amplifier is a reliable solution for those seeking high-performance audio amplification. With its powerful output, advanced technologies, and user-friendly design, it is an ideal choice for audiophiles and custom installation professionals alike who value both quality and convenience in their audio endeavors. Its blend of durability, versatility, and superior sound quality solidifies its place in the competitive landscape of audio amplifiers.