Mobile Fidelity Electronics UltraPhono Phono Stage at Vinyl Sound Toronto Canada

The UltraPhono is a reference-grade phono preamplifier from Mobile Fidelity Electronics (MoFi Electronics, USA), available at Vinyl Sound in Toronto, Canada. Its internal circuitry was developed with the assistance of Tim de Paravicini — the legendary British electronics engineer responsible for designing Mobile Fidelity Sound Lab's Gain2 Ultra Analog cutting system, the mastering chain used to cut MoFi's acclaimed Original Master Recording and UltraDisc One-Step vinyl releases. The UltraPhono brings that same wide-bandwidth transparency to home playback, with selectable gain from 40 dB to 66 dB accommodating both moving-magnet and moving-coil cartridges, adjustable loading from 75 ohms to 47 kilohms for precise cartridge matching, and a built-in Class A headphone amplifier delivering up to 8V RMS with a 31-step volume control. An external power supply isolates the sensitive analog circuitry from mains-borne noise, and switchable mono mode and a subsonic filter complete a feature set designed to serve serious vinyl playback at the highest level.

Tim de Paravicini Circuitry and Wide-Bandwidth Design

The defining characteristic of the UltraPhono is its lineage: Tim de Paravicini, whose work on the MoFi Gain2 Ultra Analog cutting lathe established the signal chain through which Mobile Fidelity's most celebrated vinyl pressings were created, contributed directly to the UltraPhono's internal circuit topology. The goal was to replicate at the playback stage the same wide-bandwidth transparency that MoFi's mastering engineers require when cutting lacquers — a standard that demands vanishingly low noise, accurate RIAA equalization, and the ability to resolve the full dynamic and tonal content buried in the groove without editorial coloration. THD measures below 0.006% in moving-magnet mode and below 0.055% in moving-coil mode, confirming that the UltraPhono's amplification stages introduce minimal harmonic distortion across the gain range. Four gain settings — 40 dB, 46 dB, 60 dB, and 66 dB — cover the output range of virtually every moving-magnet and moving-coil cartridge in current production, from high-output MM designs at 5mV and above to the lowest-output MC cartridges at 0.2mV and below.

Adjustable Loading, Subsonic Filter, Mono Mode, and External Power Supply

Cartridge loading is fully adjustable for moving-coil cartridges across six settings — 75, 100, 500, 1000, 10,000, and 47,000 ohms — allowing the UltraPhono to be tuned to the optimal termination impedance for any MC cartridge, which directly affects frequency response, channel balance, and the dynamic character of the cartridge's output. Moving-magnet cartridges are fixed at the industry-standard 47,000-ohm load with 100pF input capacitance. A switchable subsonic filter attenuates low-frequency rumble below the audio band — warp frequencies and turntable bearing noise — preventing woofer over-excursion and intermodulation distortion that subsonic energy causes in the downstream amplifier and loudspeakers. A mono mode switch sums the left and right channels electrically, enabling proper playback of mono LPs without the channel-difference noise and lateral groove noise that stereo playback of a mono record introduces. The external power supply separates the mains conversion stage from the phono and headphone amplifier circuits, eliminating the most significant source of noise ingress in phono stage design and providing a regulated, clean DC feed to the sensitive low-level gain stages inside the UltraPhono chassis.

Class A Headphone Amplifier

The UltraPhono incorporates a dedicated Class A headphone amplifier stage — a circuit topology in which the output devices conduct continuously throughout the full signal cycle rather than switching on and off, eliminating the crossover distortion that characterizes Class AB designs. With a maximum output of 8V RMS at 62 ohms and 1.5 watts per channel, the headphone amplifier drives demanding high-impedance headphones — including planar magnetic designs and 300-ohm dynamic transducers — to reference listening levels without clipping or compression. Volume is controlled in 31 discrete 2 dB steps across a 62 dB range for precise level setting, and a mute switch provides at least minus 90 dB of attenuation for silent source switching. Minimum recommended headphone impedance is 10 ohms, making the UltraPhono compatible with virtually all current headphone designs from sensitive in-ear monitors to full-size open-back reference headphones.

Key Features

• Tim de Paravicini Circuit Assistance: Internal circuitry developed with input from Tim de Paravicini, the engineer behind MoFi's Gain2 Ultra Analog cutting system, replicating the wide-bandwidth transparency of the MoFi mastering chain in a home phono stage.
• Four Selectable Gain Settings: 40 dB, 46 dB, 60 dB, and 66 dB cover the full output range of moving-magnet and moving-coil cartridges from high-output MM to ultra-low-output MC designs.
• Six MC Loading Options: Moving-coil cartridge loading adjustable across 75, 100, 500, 1000, 10,000, and 47,000 ohms for optimal cartridge termination and frequency response tuning.
• 47,000-Ohm MM Loading with 100pF Input Capacitance: Standard moving-magnet termination at the industry-accepted values for accurate frequency response and compatibility with all MM cartridges.
• Class A Headphone Amplifier: A dedicated Class A output stage delivers up to 8V RMS and 1.5 watts per channel into a 62-ohm load, driving high-impedance and planar magnetic headphones to reference levels without crossover distortion.
• 31-Step Volume Control: Discrete 2 dB per step attenuation across a 62 dB range provides precise, repeatable headphone level setting without channel imbalance at low volumes.
• Mute Switch with Minus 90 dB Attenuation: A deep mute function allows silent source switching and system changes without audible signal breakthrough.
• Switchable Subsonic Filter: Attenuates warp and rumble frequencies below the audio band to prevent woofer over-excursion and downstream intermodulation distortion.
• Mono Mode Switch: Electrically sums left and right channels for proper mono LP playback, eliminating channel-difference and lateral groove noise inherent in stereo playback of mono records.
• External Power Supply: A separate power supply chassis isolates mains conversion noise from the phono and headphone amplifier circuits for a lower noise floor and cleaner analog output.
• THD Below 0.006% MM / 0.055% MC: Low harmonic distortion figures across both cartridge modes confirm minimal coloration from the gain stages across the full operating range.
• Compatible with Headphones from 10 Ohms and Above: Wide impedance compatibility accommodates everything from sensitive in-ear monitors to full-size 300-ohm reference headphones.

Technical Specifications

Frequently Asked Questions

What is the MoFi Electronics UltraPhono?

The UltraPhono is a reference-grade phono preamplifier from Mobile Fidelity Electronics, with internal circuitry developed in collaboration with Tim de Paravicini — the engineer behind MoFi's Gain2 Ultra Analog cutting system. It offers selectable gain from 40 dB to 66 dB for both MM and MC cartridges, six MC loading options from 75 to 47,000 ohms, a switchable subsonic filter, mono mode, an external power supply, and a built-in Class A headphone amplifier delivering 8V RMS and 1.5 watts per channel with a 31-step volume control. It is available at Vinyl Sound in Toronto, Canada.

How does the UltraPhono compare to the Musical Fidelity M6 Vinyl and the Parks Audio Budgie?

The UltraPhono holds meaningful advantages over both competitors. Against the Musical Fidelity M6 Vinyl, a dual-mono phono stage with fixed MM and MC gain stages and a separate power supply, the UltraPhono adds a built-in Class A headphone amplifier with 1.5 watts per channel — an entire second component's worth of functionality — plus Tim de Paravicini's circuit involvement and direct lineage to the MoFi mastering chain that cut the records the stage is designed to play. Against the Parks Audio Budgie, a tube-based MM-only phono stage without MC capability or headphone output, the UltraPhono offers full MM and MC compatibility across four gain settings, six MC loading options, mono mode, and subsonic filtering in a solid-state design with measured THD below 0.006% in MM mode. Neither competitor combines the Gain2 mastering heritage, Class A headphone amplification, full MM and MC flexibility, and an external power supply in a single chassis at the UltraPhono's specification level.

What does Tim de Paravicini's involvement mean for the UltraPhono?

Tim de Paravicini was one of the most respected analog electronics engineers of the modern era, responsible for designing amplifiers, tape machines, and cutting systems for clients including EAR Yoshino, Esoteric Audio Research, and Mobile Fidelity Sound Lab. His work on MoFi's Gain2 Ultra Analog cutting system established the mastering signal chain used to produce MoFi's Original Master Recording and UltraDisc One-Step vinyl pressings. His assistance with the UltraPhono's circuit topology means the stage is designed to the same wide-bandwidth, low-coloration standard that MoFi's mastering engineers require when cutting lacquers — a benchmark derived from professional mastering practice rather than consumer audio convention.

How do I choose the right gain setting on the UltraPhono for my cartridge?

The correct gain setting on the UltraPhono depends on the output voltage of the cartridge in use and the sensitivity of the connected integrated amplifier or preamplifier. Moving-magnet cartridges typically output between 3mV and 6mV and work best with the 40 dB or 46 dB settings, which bring the signal to a standard line-level output without over-driving the downstream component. High-output moving-coil cartridges outputting 1.5mV to 2.5mV also suit the 40 dB or 46 dB settings. Low-output MC cartridges outputting 0.2mV to 0.5mV require the 60 dB or 66 dB settings to reach the same line level. MoFi Electronics' cartridge loading guide, included with the UltraPhono, provides a reference table matching gain and loading settings to specific cartridge models.

Can the UltraPhono drive planar magnetic headphones?

Yes, the UltraPhono's Class A headphone amplifier delivers up to 8V RMS and 1.5 watts per channel, providing sufficient voltage swing and current output to drive most planar magnetic headphones to reference listening levels. Planar magnetic designs from Audeze, HiFiMAN, and Meze Audio — which typically present impedances between 20 and 100 ohms and require more current than high-impedance dynamic headphones — fall well within the UltraPhono's minimum 10-ohm impedance specification and output power capability. The 31-step volume control provides precise level setting without the channel imbalance that resistive volume controls exhibit at low attenuation levels.

What is the subsonic filter on the UltraPhono and when should I use it?

The subsonic filter on the UltraPhono attenuates very low frequency energy — typically below 20 Hz — that enters the phono signal chain as warp noise, turntable bearing rumble, and acoustic feedback. This infrasonic content is inaudible directly but causes the woofers of loudspeakers to move visibly and consumes amplifier headroom, raising the noise floor and introducing intermodulation distortion that masks musical detail in the audible band. The subsonic filter should be engaged when playing warped records, when using a turntable in a room with significant floor-borne vibration, or whenever visible woofer movement is observed during playback. For flat, well-pressed records on a well-isolated turntable, the filter can be switched out to preserve the widest possible bandwidth.

Where can I buy the MoFi Electronics UltraPhono in Toronto or Canada?

The MoFi Electronics UltraPhono phono stage is available at Vinyl Sound, an authorized Mobile Fidelity Electronics dealer in Toronto, Canada. Vinyl Sound carries the complete MoFi Electronics electronics lineup and can assist customers across Toronto and Canada with cartridge and turntable matching, gain and loading configuration advice, and system integration for both analog and headphone listening setups.

Does the UltraPhono work as a standalone headphone amplifier without a turntable?

The UltraPhono's headphone amplifier is integrated into the phono stage chassis and operates in conjunction with the phono circuitry rather than as a fully independent line-level headphone amplifier. It is designed primarily to allow intimate headphone listening from a vinyl source without requiring a separate headphone amplifier component. For headphone listening from digital sources — a DAC, streamer, or CD player — a dedicated headphone amplifier or the headphone output of an integrated amplifier would be the more appropriate solution, and Vinyl Sound in Toronto can advise on suitable pairings for a complete analog and digital headphone system built around MoFi Electronics components.