AES Convention Papers Forum

I am the first person to complain about people who pass off marketing presentations as scientific papers, but after nearly fifty years this one actually becomes interesting because of what was presented.  Bel Losmandy built a number of modules including discrete op-amps, equalizer circuits using his discrete op-amps, and by 1971 he was selling a mixing console kit that you could built using his modules.  The schematic for this (as shown on page 4) was freely available as part of one of Bel's voluminous applications notes, and a generation of engineers designed consoles based upon this basic topology which they learned from Bel.  It turns out it's not actually all that great; the impedance of the mix buss is kind of high so the noise from all those 10k summing resistors builds up, but it's not a bad design and it's a workable design that anyone can make from standard off the shelf parts.  It came about when the small studio revolution was happening and more people were learning how to design studio gear and it influenced many many console designs.