Circuit Description

transmit port each cycle. The transmit port oper- ates at twice the frequency of the receive port. The DSP writes to the other channel of each DAC via a pair of parallel-to-serial registers (U504 and U505).

DAC OUTPUTS

Three of the DAC output channels provide Sine Out, X and Y. The fourth channel is multiplexed into eight slow outputs. Two of these are the front panel CH1 and CH2 outputs when the outputs are proportional to a trace. Four of these are the Aux D/A outputs. The last two are used to provide internal offset trims to the reference and sine discriminators.

The DSP generates sine waves using direct digital synthesis. At each 4 µs cycle, the DSP calculates the next sine output value based upon the desired reference frequency. This value is output via a DAC and converted to an analog output. This output is a sampled sine wave. To convert this to a smooth, low distortion analog sine wave, the output is filtered to remove frequency components above 100 kHz (U201-203). The filter output is scaled by DAC U206 and output by driver U207. U209 discriminates the zero crossings to provide a TTL square wave at the reference frequency. This is the TTL SYNC out as well as the feedback to the phase lock loop in external reference mode.

I/O INTERFACE TO CPU BOARD

The I/O interface provides the communication pathway between the DSP Logic Board and the main CPU Board. U610 and U613 are buffers for the address and data bus connections. Both buffer chips are enabled only when the CPU Board is writing to the DSP Logic Board. This helps isolate the activity on the CPU Board from affecting cir- cuitry on the DSP Logic Board. U608 and U609 are simple D-type latches used to hold configura- tion data for the DSP Logic Board. U606 is the main decoder PAL and generates all of the chip selects and strobes needed by the DSP Logic Board.

POWER

The bulk of the digital circuitry, the DSP and the timing PALs and the interface circuits are all pow- ered by +5V from the power supply board. The ±22V from the power supply is used to generate

±15V for the op amps. ±5.6V for analog switches and op amps is generated from the ±15V supplies. The reference and sine discriminators use separ- ate ±5V supplies regulated from the ±15V supplies as well.

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SRS Labs SR850 manual DAC Outputs, Interface to CPU Board
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SR850 specifications

The SRS Labs SR850 is a high-performance audio processor designed to enhance the listening experience across a variety of applications. With its advanced technologies, the SR850 delivers superior sound quality that is particularly noticeable in environments where audio clarity and fidelity are paramount. This device caters to audio professionals, audiophiles, and casual listeners who demand exceptional performance from their audio systems.

One of the standout features of the SR850 is its proprietary SRS 3D Audio technology. This innovative feature creates a more immersive soundstage, allowing users to experience audio as if they were in a live performance setting. By adding depth and dimension, it elevates the listening experience, making music, movies, and games far more engaging.

Additionally, the SR850 incorporates SRS dialog clarity technology, which enhances speech intelligibility in dialogues and vocals. This is particularly beneficial in film and television viewing, where dialogue can sometimes be drowned out by background music or sound effects. With dialog clarity, users can enjoy crystal-clear conversation tracks without adjusting volume levels continuously.

The device also supports various audio formats, ensuring compatibility with a broad range of media. It boasts inputs for both digital and analog sources, allowing connections to various devices such as TVs, laptops, gaming consoles, and more. The versatility of inputs makes the SR850 a convenient addition to any home entertainment system.

Another impressive characteristic of the SR850 is its compact and user-friendly design. The intuitive interface makes it easy for users to adjust settings to their preference, whether they are a novice or an audio expert. The device is equipped with programmable presets, enabling users to store their favorite sound profiles, making switching between settings quick and hassle-free.

Furthermore, the SR850 features advanced EQ capabilities, granting users the ability to tailor the audio output to their specific tastes. This personalized approach to sound adjustment enhances the overall experience, allowing users to get the most out of their audio content.

In summary, the SRS Labs SR850 is a sophisticated audio processor packed with features designed to significantly uplift sound quality and listening pleasure. With its cutting-edge technologies such as SRS 3D Audio and dialog clarity, an array of connectivity options, and customizable EQ settings, the SR850 stands out as an outstanding option for anyone looking to enhance their audio experience. Whether for professional use in sound engineering or personal enjoyment in home entertainment, the SR850 proves to be a valuable asset.
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