Magnetic Phono Preamp
This is the magnetic phono preamp I built into my DIY preamplifier years and years ago.
The original design used th UA741 op-amp. This re-design uses the NE5532 Op-amp and expands the circuit to accomodate both MC and MM cartidges with RIAA equalization. In spice testing the output is -0.5db at 20hz and 20khz, and almost totally flat through the rest.
A unique design feature is the output level control that lets you adjust for different cartridges and match levels with the rest of your gear. The maximum output is about 2 volts peak to peak, so start with the level control at mid point.
You can use any supply voltage from 9 to 24 volts. The current draw is only a few milliamps so you could even use a battery.
Of course you need to build two of these for stereo.
Now, fair warning… this is not a production circuit. The original design worked perfectly. But, you may have to do some tinkering to get this update working properly… but that’s what DIY is all about… right?
Any and all feedback on this design would be appreciated. Thank you.