Using the SR554 Without AN SRS LOCK-IN

USING THE SR554 WITHOUT AN SRS LOCK-IN

The SR554 can be powered with an external power supply. Power is applied through the 9 pin connector as described below.

PIN	VOLTAGE	CURRENT
1	+20 V	100 mA
6	-20 V	100 mA
7,8	Ground

Both voltages are required. Pins 7 and 8 should be tied together and grounded. All other pins should be left open.

COMMON MODE REJECTION RATIO The SR554 has an extremely high CMRR at low frequencies (up to 160 dB below 10 Hz). It drops off at higher frequencies due to capacitive coupling between the primary and secondary windings and reduced signal gain. See the graph below for the relationship between CMRR and frequency.

RADIATED NOISE

The SR554 reduces radiated noise from the lock- in amplifier’s input by 40 dB (100x) over most frequencies (DC to 500 MHz). To minimize radiated noise, a thick (low impedance) wire should be connected from the ground plug to a quiet

ground point. If a ground is not available near the experiment, connect a wire to the lock-in using a lug under one of the chassis screws.

INPUT IMPEDANCE

The input impedance of the SR554 appears as a combination of 0.5 Ω and

0.5H (in series) in parallel with 1.6 µF and

several parasitic impedances. The transformer primary has a DC resistance of 0.2 Ω and a primary inductance of 0.5 H. The secondary has a DC resistance of 3 kΩ and a capacitance of about 160 pF. When the secondary impedance is converted over to the primary side of the transformer by the turns ratio (1:100), the

0.5Ω, 0.5 H and 1.6 µF values are obtained. The actual values of the magnitude and phase of the input impedance is shown in the graph below.

SR554 specifications

SRS Labs SR554 is an advanced audio processing solution that aims to enhance audio quality across various media platforms. Recognized for its innovative approach to sound enhancement, the SR554 incorporates a variety of technologies designed to create a richer, more immersive listening experience.

One of the standout features of the SRS Labs SR554 is its Superior Sound technology, which employs advanced algorithms to optimize audio output for different types of content. Whether users are listening to music, watching movies, or playing video games, the SR554 intelligently adjusts the audio output to suit the specific requirements of each medium. This adaptability is crucial in today’s diverse audio landscape, ensuring that users enjoy the best possible sound quality regardless of the source.

The SR554 also integrates SRS's renowned TruBass technology, which enhances low-frequency audio signals to produce deeper, more resonant bass without sacrificing clarity. This feature is particularly beneficial for genres such as hip-hop and electronic dance music, where bass plays a pivotal role in the overall impact of the audio experience. By creating a more balanced and full-bodied sound, the SR554 caters to audiophiles and casual listeners alike.

Additionally, the SR554 is equipped with SRS Virtual Surround technology, which simulates a multi-channel audio experience from standard two-channel setups. This feature provides users with an enveloping soundstage, making it ideal for home theater systems and gaming setups. By creating a perception of height, width, and depth in sound, the SR554 enhances the realism of audio playback, making users feel as though they are part of the action.

Compatibility is another key characteristic of the SR554. The solution supports a wide range of audio formats, ensuring that it can seamlessly integrate into various devices and platforms, from smartphones to high-end audio systems. This versatility allows users to experience enhanced audio quality no matter how or where they choose to consume their media.

In terms of user customization, the SR554 offers an array of adjustable settings, allowing users to tailor their audio experience according to their preferences. This tailored approach means that whether someone seeks a more vibrant sound or a subtle auditory atmosphere, the SR554 can be fine-tuned to meet those needs.

In summary, the SRS Labs SR554 stands out in the crowded audio enhancement market through its innovative technologies geared towards delivering superior sound, enhanced bass, and immersive audio experiences. Its adaptability, compatibility, and customization options make it a compelling choice for anyone seeking to elevate their audio experience across a wide range of media formats.