Kingdom Hall Amplifier - Electronic Services Product Improved Spec
This is the standard kingdom hall amplifier supplied as part of the "Quickly built" package. It has 6 balanced microphones,
two line in and record out. Two mosfet amplifiers are fitted, one for the 100V line speaker system and the other to drive
an induction loop.
The sub circuit board fitted vertically on the right is the frequency shifter to avoid feedback. Access points are provided
to add another sub circuit board which can be a full 1/3rd octave graphic equaliser, or a more practical 5 band equaliser
**Warning** As of writing this article (2008) and revising it (2012), the loop output does NOT meet IEC international
standards and is non-complient under the terms of the DDA (Disability Discrimination Act) unless your building has NO
metal in its construction at all. See here for further information. What this really means is
that anyone hard of hearing trying to use the loop will experience a poor quality or inaudible signal that varies in
loudness and tonal quality dependant on where they are seated. This of course is totally unacceptable but easily fixed
given a little planning.