You Can DIY: A New Op-Amp for Phono Preamps - Part 2 - Development and Measurements
Brian Lowe (Belleson) developed a unique custom-designed transconductance amplifier (Bel Amp) with fully differential (balanced) low-noise JFET inputs and current output. it offers 50dB of current gain prior to any voltage excursion, virtually eliminating distortion caused by voltage-dependent node capacitance exhibited by more conventional approaches. This is the second article detailing the op-amp design, containing simulations and measurements.