Lyngdorf Audio SDAI 2175 owner manual Introduction

Introduction

Lyngdorf SDAI 2175 is a compact, high-performance analog integrated switch-mode amplifier utilizing some of the circuit topologies originally developed for the Lyngdorf Millennium and M2150 amplifiers. Due to the switch-mode topology, with an efficiency of up to 85%, the SDAI 2175 will provide its output power with minimal heat dissipation. A massive power supply with a 650VA toroid transformer and more than 40000uF capacitors ensures that the SDAI 2175 can deliver the current to drive even the most demanding loudspeakers.

The SDAI 2175 has 2 gold-plated XLR connectors accepting balanced input signals and 6 stereo inputs with 2 gold-plated RCA connectors for unbalanced signals. The SDAI 2175 has a stereo tape out of the selected line level input signal and pre out of the selected input signal after the volume control as either balanced signal from the gold-plated XLR connectors or unbalanced from the gold-plated RCA connectors.

The volume control is implemented as a high precision digital controlled analog attenuation in 0.1 dB steps over a 100 dB range. Input selection is performed via precision relays with double gold plated construction of the contact set. These kind of relays are normally only used in expensive measurement equipment for high linearity and low losses.

All controls can be operated from the front panel via the logical user interface or by use of the remote control. Or as an option the setup can be performed via a PC interface and the Lyngdorf SDAI2175 can be controlled from other Lyngdorf products capable of broadcasting control codes.

The input signal is fed to the volume control circuit via an AC coupled true instrumentation type input amplifier. Except for this AC coupling, the SDAI 2175 is fully DC coupled with no bypass capacitors or DC servos to degrade the performance. The protection circuitry in the SDAI 2175 shuts down the unit in case of over-temperature, DC voltage on the outputs and too high output current. The amplifier will resume normal operation when the fault condition is no longer present.

A trigger output on a 3.5mm jack connector allows the SDAI 2175 to control one or more SDA2175’s power condition.

- 6 -