Interfacing Ceramic Phono Cartridges to Magnetic Inputs

[Craig Maier]

Sometimes, you may encounter a situation wherein you need to connect a Ceramic (or Crystal or other Piezoelectric) phono cartridge to the Magnetic Phono Input on a Stereo Amplifier. This situation may arise out of the simple fact that you run out of inputs on your stereo receiver. I encountered this situation recently because I re-built my old RCA 45 RPM record player and had no inputs left on my receiver to connect it to, but had one extra Magnetic Phono Input to work with. Thus, I created a network to allow the two to play with each other properly, the schematic for which is attached to this thread. BTW - this circuit is more than a simple Voltage Divider (which is what it looks like). One must consider the complex impedance of the Ceramic Cartridge and the terminating impedance (R in parallel with a C) inside your receiver amplifier to analyze this network. This will produce a reasonable tonal balance approximating RIAA when used with an RIAA pre-amp.

keywords: Piezoelectric, Mag Input, Rochelle Salt