SRS Labs SR560 manual Capacitive Coupling, Inductive Coupling

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APPENDIX B

ways which these noise sources work their way into an experiment.

Capacitive Coupling

A voltage on a nearby piece of apparatus (or operator) can couple to a detector via a stray capacitance. Although Cstray may be very small, the coupled in noise may still be larger than a weak experimental signal.

3)Install capacitive shielding by placing both the experiment and the detector in a metal box.

Capacitive Noise Coupling

To estimate the noise current through Cstray into the detector we have

I = Cstray dV = jwcstray Vnoise

dt

Where a reasonable approximation to Cstray can be made by treating it as parallel plate capacitor. Here, w is the radian frequency of the noise source (perhaps 2 ∗ π ∗ 60 Hz), Vnoise is the noise voltage source amplitude (perhaps 120 VAC). For an area of A =

(0.01 m)2 and a distance of d = 0.1 m, the ‘capacitor’ will have a value of 0.009 pF and the resulting noise current will be 400 pA. This meager current is about 4000 times larger than the most sensitive current scale that is available on the SR510 lock-in.

Cures for capacitive coupling of noise signals include:

1)Remove or turn off the interfering noise source.

2)Measure voltages with low impedance sources and measure currents with high impedance sources to reduce the effect

of istray.

Inductive Noise Coupling

Inductive Coupling

Here noise couples to the experiment via a magnetic field:

A changing current in a nearby circuit gives rise to a changing magnetic field which induces an emf in the loop connecting the detector to the experiment, (emf = dØB/dt). This is like a transformer, with the experiment-detector loop as the secondary winding.

Cures for inductively coupled noise include:

1)Remove or turn off the interfering noise source (difficult to do if the noise is a broadcast station).

2)Reduce the area of the pick-up loop by using twisted pairs or coaxial cables, or even twisting the 2 coaxial cables used in differential hookups.

3)Use magnetic shielding to prevent the magnetic field from inducing an emf (at high frequencies a simple metal enclosure is adequate).

4)Measure currents, not voltages, from high impedance experiments.

B-2

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Contents Model SR560 Page Table of Contents Appendix a PCB SR560 Revision F 9/89 SchematicsCalibration and Repair Appendix BIntroduction and Setup Instrument OverviewPreparation for USE Use in Biomedical Applications Accessories FurnishedRepackaging for Shipment Environmental ConditionsPage Specifications SR560 LOW-NOISE Preamplifier Specifications ChartSpecifications Front Panel Operating Summary PowerOperation and Controls SourceFilters Gain Gain ModeReset OutputBattery Charger AC Power InputAmplifier Power Output Rear Panel Operating SummaryBlanking Input Battery Care and UsageBattery Care RS-232 InterfaceAvoid Deep Discharge Differential LOW-NOISE Front END Configurable Filters and GainCircuit Description Output StagesBattery Charger and PRE-REGULATORS Overload DetectionMicroprocessor Power Regulators Rear Panel InterfacesBatteries and P.E.M Front PanelCalibration and Repair Offset AdjustmentFront END Replacement CalibrationSR560 Offset Adjustment Procedure Battery ReplacementFuse Replacement Noise Contours Input Voltage Noise Dynamic ReserveMaximum Calibration and Repair Remote Programming CommandsAppendix a IntroductionAppendix a Intrinsic Noise Sources Appendix BNoise Sources and Cures Non-Essential Noise SourcesCapacitive Coupling Inductive CouplingResistive Coupling or ‘Ground Loops’ MicrophonicsThermocouple Effect Appendix B SR560 Component Parts List Front Panel Parts ListMain Board Parts List 22U MIN 01U Axial 804 00225-548 Insl MTP5N05 SR560 Component Parts List SR560 Component Parts List PIN Mach SR566 Assy Adhes Tape Miscellaneous Parts List SR560 Component Parts List

SR560 specifications

SRS Labs SR560 is a cutting-edge audio enhancement technology that has gained recognition for its ability to deliver an immersive sound experience. Built upon years of research, the SR560 utilizes proprietary algorithms to achieve high-fidelity sound output while maintaining an incredibly dynamic range.

One of the most notable features of the SR560 is its adaptive audio processing, which adjusts sound dynamics based on the content being played. This means that whether one is listening to music, watching a movie, or playing video games, the sound quality is optimized in real-time to provide the best listening experience. The SR560 excels at enhancing dialogue clarity in films, ensuring that important audio elements are never lost amidst background sounds.

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SRS Labs has equipped the SR560 with advanced bass optimization technology. This feature enhances low-frequency sound, providing deep, rich bass without distortion. Whether it’s the thumping beats of music or the rumble of action-packed movies, the SR560 ensures that users can experience the full spectrum of audio without compromising on quality.

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In conclusion, the SRS Labs SR560 stands out as a versatile audio enhancement technology that caters to the needs of various audio consumers. By combining adaptive processing, multi-channel support, bass optimization, and customizable profiles, the SR560 ensures a rich and immersive audio experience. As the demand for high-quality sound continues to rise, the SR560 is poised to remain a significant player in the evolution of audio technology.