Self on Audio, 2nd Edition

1

Advanced preamplifier design

A no-compromise circuit with noise gating

This was my first preamplifier design, conceived in the first year that I worked in the audio industry. The two gain-control solution to the dynamic-range problem was inspired by industry practice at the time – notably Radford and Cambridge Audio. I thought the rumble-gate concept was rather clever, but I seem to have been in a minority of one, as it was never even mentioned in the correspondence that followed. The level monitoring circuitry was perhaps a bit over the top, and I have to admit that I never once saw the ‘CLIP’ LEDs come on in real use. The clip-detect circuit proved extremely useful in other applications however, and I have been using it ever since. There is ...