MoFi Electronics UltraPhono Pro Phono Stage Preamplifier at Vinyl Sound Buffalo NY USA

The MoFi Electronics UltraPhono Pro is a single-input, all-analog phono stage preamplifier from Mobile Fidelity Electronics (Chicago, Illinois, USA), available at Vinyl Sound USA Inc. in Buffalo, NY. Designed by industry veteran Peter Madnick in direct collaboration with the MoFi Electronics engineering team, the UltraPhono Pro distills the core circuit architecture of the flagship MasterPhono into a streamlined, purpose-built phono stage focused entirely on maximum analog fidelity. Built around a fully discrete J-FET and MOSFET gain stage, a passive zero-feedback RIAA network, and a seven-stage regulated balanced power supply, the UltraPhono Pro delivers up to 71 dB of gain with RIAA accuracy held to within ±0.05 dB across a frequency response of 10 Hz to 50 kHz. This is a phono preamplifier engineered to extract everything a high-performance cartridge has to offer and deliver it with complete tonal honesty.

Peter Madnick's Circuit Architecture: MasterPhono DNA in a Single-Input Design

Peter Madnick, the engineer responsible for the circuit design of MoFi's acclaimed MasterPhono, built the UltraPhono Pro around the same foundational principles: fully discrete signal topology, zero-feedback passive RIAA equalization, and a regulated power supply architecture that eliminates the noise floor artifacts introduced by simpler supply designs. Where the MasterPhono offers multi-input flexibility and an expanded feature set, the UltraPhono Pro channels that same engineering philosophy into a single-input implementation, removing complexity without compromising the electrical fundamentals that determine sonic performance. The result is a phono stage that inherits the MasterPhono's commitment to natural transients and tonal accuracy while presenting a more direct signal path and a chassis format optimized for long-term system integration.

Zero-Feedback Passive RIAA and Seven-Stage Regulated Power Supply

The RIAA equalization network in the UltraPhono Pro is entirely passive and operates without feedback, a design choice that preserves the leading-edge behavior of transients and avoids the phase anomalies associated with active feedback-based equalization circuits. Precision film-foil components maintain the equalization curve to within ±0.05 dB, a figure that holds across the full 10 Hz to 50 kHz bandwidth and reflects the same accuracy standard MoFi's mastering engineers apply in the studio. The seven-stage regulated balanced power supply addresses the power delivery side of the noise equation with equal rigor, providing a stable, low-impedance reference that allows the discrete J-FET and MOSFET gain stages to operate at their full dynamic capability. Total harmonic distortion is measured at 0.005% A-Weighted at 10 mV input and 40 dB gain, confirming that the circuit's low-noise architecture translates directly into measurable real-world performance.

Front-Panel Controls: Gain, Loading, Mono, Subsonic, Mute, and Dim

The UltraPhono Pro places all cartridge-matching controls on the front panel, providing direct access to gain settings of 40 dB, 52 dB, and 65 dB via RCA output (46 dB, 58 dB, and 71 dB balanced) and loading options of 100, 300, 500, 1k, and 47k Ohms. This configuration supports moving-magnet cartridges at the 47k Ohm standard setting and accommodates the full range of moving-coil cartridges from high-output MC down to low-output designs requiring maximum gain. Beyond cartridge matching, the front panel provides mono, subsonic filter, mute, and dim controls — practical listening tools that allow adjustments for mono pressings, warped records, and level management during a session without interrupting playback. The chassis is constructed from brushed aluminum panels over a rigid steel frame, measuring 17 x 2.5 x 11.35 inches and weighing 7 lb.

Key Features

• Designed by Peter Madnick: The UltraPhono Pro shares its core circuit architecture with MoFi's flagship MasterPhono, designed by industry veteran Peter Madnick with a focus on ultra-low-noise discrete topology and passive RIAA accuracy.
• Fully Discrete J-FET and MOSFET Gain Stages: Both input and output stages are built from discrete transistors rather than integrated op-amp chips, preserving the natural dynamic behavior and tonal character of the source signal.
• Passive Zero-Feedback RIAA Equalization: A passive RIAA network with no feedback loop maintains equalization accuracy to within ±0.05 dB, protecting transient integrity and tonal honesty throughout the audio band.
• Seven-Stage Regulated Balanced Power Supply: An exceptionally quiet seven-stage regulated supply eliminates power-supply-induced noise and provides a stable low-impedance voltage reference for the gain stages.
• Up to 71 dB Balanced Output Gain: Three selectable gain settings on both balanced XLR and unbalanced RCA outputs accommodate moving-magnet and the full range of moving-coil cartridges from high to ultra-low output.
• Five Loading Options: Front-panel loading selection of 100, 300, 500, 1k, and 47k Ohms provides accurate impedance matching for virtually every MM and MC cartridge in current production.
• Front-Panel Listening Controls: Mono, subsonic filter, mute, and dim functions are accessible from the front panel for practical session adjustments without interrupting playback.
• Precision Film-Foil Components: Critical RIAA network parts use precision film-foil construction for long-term value stability and consistent equalization accuracy.
• Brushed Aluminum and Rigid Steel Chassis: A brushed-aluminum panel over a rigid steel frame provides structural damping and a professional aesthetic consistent with the MoFi Electronics component lineup.

Technical Specifications

Frequently Asked Questions

What is the MoFi Electronics UltraPhono Pro?

The MoFi Electronics UltraPhono Pro is a single-input, all-analog phono stage preamplifier designed by Peter Madnick and built by Mobile Fidelity Electronics in the USA. It features a fully discrete J-FET and MOSFET gain topology, a passive zero-feedback RIAA network accurate to ±0.05 dB, a seven-stage regulated balanced power supply, and front-panel gain and loading controls supporting both moving-magnet and moving-coil cartridges. It delivers up to 71 dB of balanced output gain with measured THD of 0.005% A-Weighted, positioning it as a high-performance phono preamplifier aimed at serious analog listeners who value circuit simplicity and measurable accuracy over feature proliferation.

How does the UltraPhono Pro compare to the MoFi MasterPhono?

The UltraPhono Pro shares its core circuit architecture with the MoFi MasterPhono, including the discrete J-FET and MOSFET gain stages, the passive zero-feedback RIAA network, and the precision regulated power supply design. The principal distinction is configuration: the MasterPhono offers multiple inputs, a transimpedance gain option, metering, and a more comprehensive feature set for audiophiles who manage multiple analog sources, while the UltraPhono Pro is a single-input implementation that removes that complexity in favor of a more direct signal path and a lower-profile chassis. For listeners with one primary turntable, the UltraPhono Pro delivers the same foundational engineering without paying for features that will go unused.

How does the UltraPhono Pro compare to the Pro-Ject Tube Box DS3 B and the Parasound JC 3 Jr.?

The MoFi UltraPhono Pro competes directly with the Pro-Ject Tube Box DS3 B and the Parasound JC 3 Jr. in the serious analog phono stage category. The Pro-Ject Tube Box DS3 B uses a tube output stage that imparts a characteristic tonal softness, while the UltraPhono Pro's fully discrete solid-state topology prioritizes linearity and low noise. The Parasound JC 3 Jr. is a respected discrete solid-state design, but the UltraPhono Pro adds a seven-stage regulated balanced power supply and passive zero-feedback RIAA not found in the JC 3 Jr., along with front-panel gain and loading access versus the Parasound's under-chassis DIP switches. The UltraPhono Pro's ±0.05 dB RIAA accuracy is also a more stringent specification than either competitor publishes.

What cartridge types does the UltraPhono Pro support?

The UltraPhono Pro supports both moving-magnet and moving-coil cartridges through its five loading options and three gain settings. Moving-magnet cartridges operate at the standard 47k Ohm loading with 40 dB or 52 dB RCA gain. High-output MC cartridges function well at 52 dB or 65 dB gain with loading in the 100 to 500 Ohm range. Ultra-low-output MC cartridges requiring maximum gain are supported at 65 dB RCA or 71 dB balanced output. The cartridge weight range accepted by the tonearm is independent of the phono stage, so the UltraPhono Pro pairs with any cartridge whose output and impedance fall within those parameters.

What is zero-feedback passive RIAA equalization and why does it matter?

RIAA equalization is a standardized curve applied during vinyl mastering that boosts high frequencies and cuts bass during the cutting process, requiring the phono stage to apply the inverse curve on playback. A passive RIAA network achieves this correction using resistors and capacitors without any active feedback loop, which means the circuit does not sample its own output and correct errors in real time. Zero-feedback designs are valued by analog engineers because feedback, while effective at reducing distortion figures, can introduce phase shifts and alter the way the circuit responds to rapid transient information. The UltraPhono Pro's passive zero-feedback RIAA network preserves the leading-edge accuracy of instrumental attacks and the natural decay of acoustic instruments in a way that feedback-based designs can subtly compress.

Does the UltraPhono Pro have balanced XLR outputs?

Yes. The UltraPhono Pro provides both balanced XLR and unbalanced RCA outputs simultaneously, with balanced output gain of 46 dB, 58 dB, and 71 dB and balanced output impedance of 230 Ohms. The balanced output offers an additional 6 dB of gain over the RCA output at each equivalent gain setting and provides the common-mode noise rejection benefit of differential signaling for long cable runs or in systems where line-level interference is a concern. The unbalanced RCA output at 115 Ohms output impedance is suitable for connection to any standard preamplifier or integrated amplifier with a line-level input.

Where can I buy the MoFi Electronics UltraPhono Pro in Buffalo or Western New York?

The MoFi Electronics UltraPhono Pro Phono Stage Preamplifier is available at Vinyl Sound USA Inc., an authorized Mobile Fidelity Electronics dealer located in Buffalo, NY. Vinyl Sound serves audiophiles across Western New York and the greater Buffalo region and can assist with cartridge matching, gain and loading configuration, and complete analog system consultation for turntable, tonearm, cartridge, and phono stage combinations in-store or by appointment.