The Topping Pre900 also includes support for 12V trigger input and output for synchronized power control between connected devices. In integrated desktop systems, compatible upstream and downstream components can be automatically turned on and off together, reducing the need for manual sequencing.
Volume adjustment is accomplished via a relay-switched resistor network with 1000 steps of attenuation in 0.1 dB increments. The relay-controlled design maintains channel alignment during low-volume listening while allowing repeatable level adjustments without the tracking inconsistencies associated with traditional analog potentiometers. Three gain settings – low, medium and high – allow the Pre900 to accommodate both highly sensitive downstream equipment and systems that require additional voltage amplification.
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