PDF schematic of a low pass filter built around the 5532 dual op-amp, intended to feed an audio power amplifier, 126 KB in size; the name suggests it was shared alongside a video tutorial. Such a filter is commonly used ahead of a subwoofer amplifier to remove higher frequencies. Technicians can check the op-amp supply rails, the filter component values and signal path when diagnosing distortion or silence. The name states no board revision, so verify values against the actual build.
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The standard format for schematics, block diagrams, power-sequence charts and service manuals.