You Can DIY: A New Op-Amp for Phono Preamps Part 1 - The Design
Brian Lowe (Belleson) developed a unique custom designed transconductance amplifier (Bel Amp) with fully differential (balanced) low noise JFET inputs and current output for phono preamps. This article details the requirements and parameter values, while exploring design options. A second article explains the discrete op-amp design, complete with simulations and measurements.