The Lyngdorf SDA-2175 is a premium power amplifier engineered for uncompromised audio performance. It functions effectively as a controllable amplifier within Lyngdorf systems or as a power amplifier paired with traditional pre-amplifiers. Unlike conventional Class D amplifiers, the SDA-2175 employs an advanced output stage utilizing Pulse Width Modulation (PWM) combined with patented switch speed optimization technology. This innovation results in low natural distortion and notable performance improvements due to reduced feedback requirements. The device features a fully balanced signal path that extends from input to output, ensuring an exceptional signal-to-noise ratio, outclassing standard Class D amplifiers. Key design elements include a low-noise Holmgren toroidal transformer that implements feed-forward compensation to minimize output variations, rather than relying solely on error correction. This approach is derived from the design principles of the Millennium model. The output stage is constructed with high-quality components, including polypropylene capacitors and linear ferrite materials, aimed at achieving low, frequency-independent distortion, allowing for accurate reproduction of musical instruments and other sound sources. The term 'Semi Digital' reflects its design where an analog input drives a digital switching amplifier. The amplifier supports full signal balancing, improving noise and hum isolation, and maintaining high audio quality throughout. Additionally, the internal feedback loop is designed to be fully balanced. The construction favors DC coupling throughout, reducing discussions about capacitor quality, utilizing only the finest components such as ultra-low distortion Burr-Brown op-amps in the input stage, and high-grade polypropylene capacitors in the output reconstruction filter.
