Lyngdorf TacT SDAI-2175 amplifier

Lyngdorf SDAI 2175 is a compact, high performance semi digital integrated switch-mode amplifier utilizing some of the circuit topologies originally developed for the Lyngdorf Millennium amplifier. 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 and operation can be performed via a PC interface.

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.

 

Specifications

Balanced Input Connectors:  3 pin XLR, gold-plated.

Balanced Input Impedance:  10 k Ω   (AC-coupled)

Balanced Input CMRR:  40 dB (20 Hz - 20 kHz)

Unbalanced Input Connectors:  RCA (phono) jack, gold-plated

Unbalanced Input Impedance:  100 k Ω  (AC-coupled)

Tape Out Output Impedance:  75 Ω   (Gain 0  dB ref. active input)

Pre Out Output Impedance:  75 Ω   unbalanced; 100  balanced (Gain According to volume control setting. 88 dB = 0 dB with sensitivity 0 dB and rel. Volume 0 dB)

Max. Input Voltage:  ±12Vp AC, 0 - 20 V DC.

Input Sensitivity:  2 V (1V with high sens.) 200 W/8 Ω 

Voltage Gain:  26 dB

Output Connectors:  4 insulated binding posts, goldplated. (Will accept bare wire ends of up to 5 mm diameter)

Output Power (8 Ω ):   2 x 200 W (1KHz, 1% THD+N)

Output Power (4 Ω ):   2 x 375 W (1KHz, 1% THD+N)

Nominal Load Impedance:  4 Ω  - 8 Ω  (It is safe to operate the amplifier with no load)

Frequency Response:  0,3 Hz - 33 kHz (-3 dB points, 8 Ω  load)

Frequency Response:  -0 dB /+0,2 dB (20 Hz - 20 kHz, 8 Ω  load)

Frequency Response:  -0,2 dB / +0 dB (20 Hz - 20 kHz, 4 Ω  load)

Output Impedance:  0,035 Ω   (20 Hz - 1 kHz)

Output Impedance:  0,4 Ω  (20 kHz)

THD+N, (1 W/8 Ω ):   0,004% (A-wgt.)

THD+N, (1 W/4 Ω ):   0,006% (A-wgt.)

THD+N, (100 W/8 Ω:  0,01% (A-wgt.)

THD+N, (180 W/8 Ω:  0,07% (A-wgt.)

THD+N, (375 W/4 Ω:  0,07% (A-wgt.)

Signal-to-Noise Ratio:  113 dB (A-wgt. Ref. 200 W/8 Ω )

Channel separation:  84 dB (1 kHz, 200 W/8 Ω )

Peak output current:  –40 A

Output Common Mode Voltage:  35 V DC (Ref. Ground. The amplifier can not be used in bridged mono mode)

Output DC Voltage:  ±5 Mv

Output Short Circuit Current:  –40 A

Output DC Voltage:  –5 V at <0,1 Hz

Over Temperature:  All heat sinks and mains-transformer.

Mains Input Connector:  IEC 320 cold type (Mains lead supplied)

Mains Voltage Range:  100 - 120 V AC, 50/60 Hz (115 V version)

Mains Voltage Range:  200 - 240 V AC, 50/60 Hz (230 V version)

Internal Mains Fuse:  8 Amp (115 V version)

Internal Mains Fuse:  4 Amp (230 V version)

Power Consumption:  1,5 W (STANDBY mode)

Power Consumption:  35 W (OPERATE mode, no output)

Power Consumption:  116 W (2 x 37,5 W/4 Ω)

Power Consumption:  820 W (2 x 300 W/4 Ω)

Dimensions (W x H x D);  450 x 100 x 355 mm (17,72" x 3,94" x 13,98")

Weight:  13 kg (28,66 lb)