Op-amp Based Preamp for Moving Magnet (MM) and Low Output Moving Coil (LOMC) Phono Cartridges
This project is a departure from that of my normal sort. It is based around an operational amplifier (op-amp)… Yup I’ve transgressed to the dark side. Actually I have nothing against integrated circuits (IC) or solid state devices and in fact use a number of solid state components in my designs. This project is for a relatively simple high performance phono preamplifier that can handle both moving magnet (MM) and low output moving coil (LOMC) cartridges. The basis for the project was a temporary need to have a LOMC preamp in addition to the valve (vacuum tube) ones I have to study low noise performance. Without trying to start any arguments, I have found that it is a lot easier to make a low noise high gain solid state circuit than it is to do the same for valve circuit of similar capabilities. The circuit I came up with is pretty much like many common op-amp based phono preamplifier circuits.
DIY OPA2134 RIAA Phono Preamplifier (MM / MC) - [Link]