Phonostages — MoFi Electronics STUDIOPHONO

The StudioPhono is a compact solid-state phono preamplifier that accepts both MM and MC pickups from MoFi Electronics. It was designed by Tim de Paravicini, the engineer who created the Gain2 Ultra Analog cutting system used by Mobile Fidelity Sound Lab at its mastering studio in Sebastopol, California. MoFi builds the unit in the USA at its Michigan facility, and the brand lists it at USD 349. It is the more affordable of MoFi's phono stages, below the UltraPhono.

Key specs that matter

The user can pick 40, 46, 60 or 66 dB of gain, which covers low and high output cartridges. Moving magnet loading is fixed at 47,000 ohms, while moving coil loading can be set to 75, 100, 500, 1,000, 10,000 or 47,000 ohms. Input capacitance is 100 pF. At the rear sit a pair of RCA inputs, a pair of RCA outputs and a grounding post for the turntable earth lead. MoFi quotes total harmonic distortion below 0.01% for the moving magnet path and below 0.012% for moving coil. The case measures about 98 x 32 x 181 mm and weighs about 0.51 kg, so it fits on a shelf beside the turntable.

Engineering and use context

MoFi says the aim was to bring the wide bandwidth that its own mastering engineers work with into a home analogue system. Gain and loading are changed with small toggle switches on the underside of the case, so no tools are needed when a cartridge is swapped. Two push buttons on the front engage the filters. The mono filter is intended for vintage mono LPs, and the subsonic filter deals with warped records and with vibrational feedback that builds up at higher volume. Power comes from an external balanced supply of universal type, which MoFi says is there to minimise noise. A yellow indicator light and the MoFi logo sit above the two filter buttons on the fascia.

Pairing

The six-step coil loading lets the stage be matched to the load a cartridge maker specifies, from very low impedance coils up to the standard setting that also suits high output moving coil designs. The two highest gain settings are there for low output coil designs, and the two lowest for moving magnet types. Output is a line-level signal for any integrated amplifier or preamplifier input without its own phono circuit.

Alternatives

The MoFi UltraPhono adds a Class A headphone amplifier and a 6 dB better signal to noise ratio to the same gain and loading options.