The principal use of your new 418 Limiter is to condition arbitrary complex audio signals (not just single tracks, although the 418 may be used with these, too) in such a way that they can be recorded on tape or optical film without overload, excessive noise, or distortion due to excessive high frequencies, In order to do this while introducing minimal artifacts into the signal, the 418 incorporates a highly refined program-controlled release time circuit, as well as a separate high-frequency limiter which can control the high frequencies present in the program on an instantaneous basis without distortion and without disturbing the basic program loudness. The release time and high-frequency limiter are both adjustable by the user in order to obtain the desired amount of high-frequency control, level control, compression, and density augmentation. The controls have been arranged to minimize the probability of audible side-effects of an undesirable nature regardless of their settings. Some uses of the 418 include: (1) mixing through while doing multitrack reductions in order to save time while doing radio commercials, demo sessions, and the like; (2) conditioning recorded program material so that it can be copied onto cassette or low-speed tape without excessive hiss and/or high-frequency distortion; (3) transferring from magnetic to optical film; (4) transferring from disc to 7.5 ips tape cartridge in broadcast stations; (5) recording production work through in broadcast production studios; and (6) transferring from tape to disc (with certain limitations — see OPERATING INSTRUCTIONS). Other applications will doubtless suggest themselves to the creative engineer. The 418 is not rigorously RFI/EMI shielded, and its output contains substantial amounts of fast overshoots. It is therefore specifically not recommended for driving broadcast transmitters. Orban Associates Division manufactures a line of devices, the OPTIMOD-FM and the OPTIMOD-AM, specifically designed for this purpose.