Phono Preamplifiers

Despite the name, MoFi's UltraPhono Pro is derived from the flagship MasterPhono [HFN Dec '23, pictured here], not the calculator-styled UltraPhono [HFN Mar '20]. The stripped-down UltraPhono Pro shares the MasterPhono's fully discrete, DC-coupled (servo controlled) input and output stage circuits but lacks the low impedance 'current input', the meters and remote control. It also leverages the same passive RIAA network, employing 1% tolerance polypropylene film/foil capacitors and 0.1% tolerance resistors. A similar, switching regulator-based PSU minimises hum fields while multiple, cascaded voltage regulation stages are deployed to further suppress noise. However, the UltraPhono Pro has a cost-effective single box construction instead of the split front supply/rear signal path design of the MasterPhono.

The UltraPhono Pro offers three gain selections (+40dB, +52dB and +65dB) instead of the MasterPhono's four (+40dB, +50dB, +60dB and +70dB) although the newcomer's practical +46dB to +71dB gain range is really no different from the flagship's +44dB to +74dB [see PM's Lab Report]. Both phono preamps have the same very extended frequency response and subsonic filter option, and offer very similar A-wtd S/N ratios, input overload margins and trends of distortion vs. frequency and output level. The MasterPhono has a lower output impedance but, otherwise, the similarities in their core design are betrayed by the numbers... PM