Power amplifiers, when driven out of their linear range of operation, sound particularly bad, and can produce damage to themselves or the transducers to which they are connected. (formerly Application Note 102)ĭesign Note 03 - Signal Limiter for Power Amplifiers (95k) While several methods are available to the designer, the best combination of sound quality, control range, and control resolution can be obtained from two easily combined building blocks - a high performance, exponential-control, Voltage Controlled Amplifier (VCA), and a low-cost Digital-to-Analog Converter (DAC). What is often needed, however, are methods for varying the gain and other parameters of the analog circuitry, under digital control. In many cases, a fully analog signal path provides the least compromise to sonic integrity, and ultimately delivers the best sounding audio products at the lowest cost. Consider a THAT Analog Engine instead.ĭesign Note 02 - Digital Gain Control with Analog VCAs (153k) Note: The THAT2252 is no longer available. This application note offers insights into circuit designs based on these log-responding components. Both feed-back and feed-forward configurations are possible. The detector is used to sense signal level and control the gain of the VCA to produce compression or expansion.

Consider a THAT Analog Engine instead.ĭesign Note 01A - The Mathematics of Log-Based Dynamic Processors (64k)ĭynamic Processors (compressors, expanders, gates, etc.) may be easily constructed from THAT Corporation Voltage-Controlled Amplifiers (VCAs) and RMS-Level Detectors. This application note describes in detail the circuitry for two basic compressor / limiter designs using these devices. THAT Corporation's 2252 RMS Level Detector and 2180/2181 Series Voltage-Controlled Amplifiers (VCAs) are ideal basic building blocks for compressor / limiter designs. Some of the design issues which you will need to consider are addressed here.ĭesign Note 00A - Basic Compressor/Limiter Design (113k) To ensure your production doesn’t miss a beat, we have an alternative that is worth considering, our THAT2162 dual Blackmer VCA.

The design notes are provided in Adobe' s PDF format.Īnalog Devices recently discontinued their SSM2164 quad VCA. IC Products > Design Support > Design Notesĭesign Notes THAT Corporation design notes contain detailed information on how to use our products in specific real-world circuits.

Noise gates and compressors