One phono stage for cartridges that behave very differently

The MoFi MasterPhono is an all-analog phono preamplifier designed with Peter Madnick for serious moving-magnet and moving-coil systems. Instead of forcing every cartridge through one input topology, it provides conventional voltage-mode inputs through RCA and XLR connections as well as a current-mode, or transimpedance, input for low-impedance moving-coil cartridges. That second approach presents a near-zero input impedance, allowing the cartridge's current output to determine the signal while reducing sensitivity to cable capacitance and radio-frequency interference.

Conventional voltage operation remains highly adjustable. Four gain settings—40, 50, 60 and 70 dB—cover a wide range of cartridge outputs. Ten impedance choices run from 15 ohms to 47 kilohms plus 150 pF, and a custom option permits a user-selected load through an RCA plug. That flexibility matters when comparing cartridges or optimizing a collection that includes more than one arm or turntable.

The dual-chassis layout keeps the power supply physically separate from the small phono signal. Fully discrete balanced circuitry, cascaded voltage regulation, passive RIAA equalization and DC coupling address noise and signal integrity at different stages of the circuit. MoFi specifies RIAA accuracy within ±0.05 dB and frequency response from 10 Hz to 50 kHz within ±0.20 dB.

The front-panel meters are functional rather than decorative. They can monitor signal or assist with cartridge-azimuth calibration. Remote control covers input selection, gain, mute, mono, meter functions and the subsonic filter, allowing meaningful changes from the listening position without hiding the important setup choices in an app.

Command Performance AV can determine whether voltage or current mode best suits a particular cartridge, establish gain and loading by measurement and listening, and integrate the MasterPhono with balanced or single-ended downstream electronics. That matching work is especially important when the source signal is measured in fractions of a millivolt.