Automatic Analog Preamp Gain Control Using Digital Command
Automatic Gain Control (AGC) is a common tool for field recording, but it usually requires specific hardware such as voltage controlled amplifiers. In this paper, we address the problem of designing an AGC when none of this hardware is present, using an ubiquitous digitally controlled high end analog preamp. To do this, we have to overcome two problems: fixed gain steps and variable delay of the gain command. In order to propose an efficient solution, we will first study the effects of each of those two problems. Finally, a very simple digitally controlled automatic gain, but of high quality will be proposed, using only 10MIPS of processing power from our high end USB sound card.
Click to purchase paper or login as an AES member. If your company or school subscribes to the E-Library then switch to the institutional version. If you are not an AES member and would like to subscribe to the E-Library then Join the AES!
This paper costs $20 for non-members and is free for AES members and E-Library subscribers.
The Engineering Briefs at this Convention were selected on the basis of a submitted synopsis, ensuring that they are of interest to AES members, and are not overly commercial. These briefs have been reproduced from the authors' advance manuscripts, without editing, corrections, or consideration by the Review Board. The AES takes no responsibility for their contents. Paper copies are not available, but any member can freely access these briefs. Members are encouraged to provide comments that enhance their usefulness.