Sansui AU-9900 - Pre Loved Classic AU series with custom timber surround

The pre-main amplifier achieves improved audio performance and operability through the adoption of a unique chassis structure.

The AU-9900 features a partitioned internal layout, with the preamplifier and tone control sections positioned at the front panel, while the power amplifier and power supply components—such as the heat sinks and power transistors—are located at the rear. This design integrates each functional block within a single pre-main amplifier while maintaining electrical independence, effectively reducing mutual interference.

Input terminals for source components are mounted on the front right side panel, while speaker output terminals are located on the left side panel. This arrangement allows signal flow to be amplified smoothly along the shortest possible path. In addition, the close proximity of the input terminals, selector switch, and equalizer amplifier minimizes the need for shielded wiring and prevents high-frequency degradation caused by stray capacitance.

The power amplifier section employs a fully direct-coupled pure complementary OCL configuration, with a differential amplifier circuit at the input stage. The output stage uses a parallel push-pull design, delivering ample power with low distortion.

The equalizer section input circuit consists of two stages—a flat amplifier and an equalizer amplifier—both utilizing differential amplifier circuits with dual transistors. RIAA equalization is achieved using a CR + negative feedback configuration that independently performs high-pass and low-pass filtering, resulting in more accurate RIAA response and improved phase characteristics.

Please note: Collection from our Murarrie showroom or freight at buyer's expense. We do not offer free shipping on traded equipment.

Contact The Audio Tailor today to arrange an audition.