The Audio Throtle is the first of several modules we are making for the API 500 series (TM) rack. Its purpose to to serve as both a transparent line amp as well as a pad for use after a mic preamplifier. It is designed so that you can use a lower gain preamp with a low output microphone such as a ribbon microphone, but still achieve proper levels. This allows you to retain the sonic characteristics of the mic preamp without any added noise. The pad feature also allows you keep preamp that has a hotter output from overdriving the input stage of the next device in line. The Audio Throttle is equipped with a custom Grayhill switch that allows repeatable gain settings, both for the pad and for the line amp sections.
Below is the image of the prototype Audio Throttle, which in this photo is loaded with a Forssell Technologies 993 discrete op amp. This will be an upgrade option for the Audio Throttle, and can be installed at any time.