| 摘要 |
The invention relates to a phantom-powered, balanced audio dynamics processor suitable for direct connection to conventional balanced output electrodynamic or capacitor microphones. The device provides dynamic range compression. The device includes a low-noise, low-power balanced analog variable gain amplifier (VGA) based on a long-tailed pair TR1 & TR2, and a microprocessor-controlled side chain for level detection, dynamics processing and linearization of gain control. In an embodiment, the microprocessor IC1 effects control of gain by varying the conductivity of FET TR3. The microprocessor also controls the user interface and display. The VGA and the microprocessor are arranged in a series totem-pole configuration which includes the indicator LEDs. In embodiments, the device is sufficiently small to fit within the shell of an XLR male to female adapter, a quarter inch jack plug, or within the body of the microphone itself. The form factor of the product and the fact that it requires no separate power supply or batteries, means that the benefits of compression (specifically improved audibility and intelligibility of the human voice) may be exploited where microphones are used (e.g. in public address systems in noisy environments such as railway stations or airports) but compression has hitherto been too inconvenient.
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