CIRCUIT DESCRIPTION

adjustment is provided by this stage. U405B, half of an AD7528 dual 8-bit DAC is used to provide a ±5 volt offset voltage at the non-inverting input of U402. The front panel offset control also sums at this junction, and provides an offset voltage of ±5 V that is buffered by U407D.

Following amplifier U402 is the other half of the 8-bit DAC U405A, which along with op- amp U404 forms a digital gain vernier. This vernier is used in calibration to compensate for gain variances that occur with configuration changes such as input coupling and filter settings. This DAC also provides the front panel "uncal" gain vernier function.

The sixth and final gain stage consists of U403 and output buffer U406, configured for a gain of 5 and with input attenuator U409 to select overall gains of 1, 2, or 5. The LM6321, (U406) provides the output drive capability for both the 600Ω and 50Ω outputs.

OVERLOAD DETECTION

The overload detector constantly monitors the front-end output, filter 1 output, U402 (after the second filter) output, and final stage output for excessive signal levels. Comparator U408 compares both positive and negative signal excursions against a 5 volt reference and lights the front panel overload indicator if any levels are excessive.

MICROPROCESSOR

The system processor U503 is a CMOS Z80 processor running at 4 MHz. The system clock consists of Schmitt trigger U506A and an R-C network. The oscillator is designed so that latch U508A can shut down the clock oscillator completely, thereby disabling all digital circuits in the amplifier so that no digital noise will be present. The processor and clock only run when a front

panel key is pressed and instrument settings are to be changed, or while there is activity on the RS-232 port.

The SR560 uses a 16 K x 8 CMOS EPROM, (U504) containing system firmware and calibration bytes, along with a 2 K x 8 CMOS RAM, (U505) which is battery backed-up at all times to retain instrument settings.

U507 generates port strobes for system IO, and U510 provides a buffered data bus. The buffered data bus is active only during IO instructions to keep digital noise in the amplifier to a minimum while the processor is running.

U601 through U606 are control latches providing the 48 DC control lines that configure all of the instrument's hardware. U607 is an input buffer and takes data from the front panel and RS-232, as well as providing a processor input indicating line operation and address from SW601 for ganged RS-232 operation. SW601 additionally controls power to the front panel LED’s through positions 3 and 4.

BATTERY CHARGER AND PRE-REGULATORS

The 17 volt AC line transformer provides unregulated power for both amplifier operation and battery charging. Diode bridge D706 and filter capacitors C706 and C707 generate unregulated DC that is pre- regulated to ±12 VDC by U706 and U707 to take the place of the batteries when the instrument is operating on AC line power. Relay U705 switches the amplifier from battery to pre-regulated AC whenever the AC line cord is plugged in.

Diode bridge D710 and C709 and C710 provide unregulated DC to charge the batteries. U701 and U702 operates as "AC" regulators, limiting peak battery charging voltage. As there are two positive batteries and one negative battery, U701 is a LM350

14

Page 17 Page 19
Page 18
Image 18
SRS Labs SR560 manual Overload Detection, Microprocessor, Battery Charger and PRE-REGULATORS
Page 17 Page 19

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.

Another key characteristic of the SR560 is its support for multi-channel audio. With the rise of surround sound systems, the SR560 is designed to integrate seamlessly with 5.1 and 7.1 speaker setups. This ensures that users can enjoy a true surround sound experience, where each audio channel is processed independently to create a lifelike auditory environment. The SR560’s processing capabilities allow it to convert standard stereo audio into multi-channel output, enriching the listening experience for any audio format.

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.

Furthermore, the SR560 showcases state-of-the-art sound management features that provide users with customizable audio profiles. This allows users to tailor their audio experience according to personal preferences, whether they prefer a more balanced sound, enhanced bass, or boosted treble frequencies. The intuitive interface ensures that adjustments can be made effortlessly.

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.
Top Page Image Contents