NEW: TOPPING PRE900 DESKTOP PRE-AMP
NEW From TOPPING: Pre900 Pre-Amp
The TOPPING Pre900 is a fully-balanced desktop preamplifier designed for dedicated two-channel systems and flagship headphone stacks. Built around a four-channel differential architecture, the Pre900 combines precision relay volume control, three balanced combo inputs, independent power supplies, and a dedicated balanced output stage in a compact desktop chassis. Measured performance includes THD+N rated at 0.00005% at 1kHz A-weighted, THD below 0.00003% from 20Hz to 20kHz, and a 151dB signal-to-noise ratio and dynamic range, placing the focus on low-noise operation and accurate signal handling throughout the gain stage.
Fully-balanced architecture and relay attenuation
The Pre900 uses a true end-to-end differential signal path with separate amplification stages for each phase of the left and right channels. Physical channel isolation helps reduce electromagnetic interference and crosstalk as signals move from input to output. Crosstalk remains below -150dB, maintaining channel separation even during fine volume adjustments and preserving stereo image stability in balanced systems.
Volume adjustment is handled through a relay-switched resistor network with 1,000 steps of attenuation in 0.1dB increments. The relay-controlled design maintains channel matching 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 adapt to both high-sensitivity downstream equipment and systems requiring additional voltage gain.
Headroom and low-noise operation
With output swing up to 69Vpp and gain up to 19.9dB, the Pre900 provides substantial voltage headroom for demanding power amplifiers and balanced headphone systems. The available output range allows transient peaks to pass without prematurely reaching clipping limits, particularly in systems with lower-sensitivity amplification stages or wide dynamic range program material.
The actual noise floor is rated below 0.3μVrms at low gain, reducing residual circuit noise when paired with sensitive downstream equipment. THD remains below 0.00003% across the audible range from 20Hz to 20kHz, keeping harmonic distortion consistently low across varying frequencies and output conditions rather than only at a single measurement point.
Balanced connectivity and system integration
The Pre900 includes three stereo balanced combo inputs using Neutrik XLR and 6.35mm TRS combo sockets. The input configuration supports balanced DACs, studio interfaces, and professional audio equipment without requiring adapters or external switching hardware. A dedicated pair of XLR balanced outputs provides a direct signal path to power amplifiers or downstream balanced components.
TOPPING also includes 12V trigger input and output support for synchronized power control between connected devices. In integrated desktop systems, compatible upstream and downstream components can automatically power on and off together, reducing the need for manual sequencing.
Display and user controls
A 2.0-inch high-definition color display provides access to playback information, gain settings, channel balance adjustment, safe volume mode, FFT visualization, and VU meter display modes. Front-panel operation combines three touch buttons with a multifunction rotary control, while the included infrared remote allows full adjustment from a listening position.
The chassis design follows the same low-profile edge-line styling used throughout TOPPING’s 900 Series components, including the D900 DAC and A900 headphone amplifier. The matching dimensions and visual layout allow the Pre900 to function as part of a compact balanced desktop stack without unnecessary footprint.
