Phasemation EA-550 Phono Amplifier (Dual-Chassis / Separate Unit)

All-stage symmetrical non-feedback phonostage in two monaural boxes, with balanced inputs, split chassis, and refined MC transformer

For the EA-550, Phasemation pushes the dual-mono idea to the logical conclusion by having two separate units for each channel. It is a fully discrete, all-stage symmetrical non-feedback phonostage, and its construction and circuitry aim to reveal the fullest realism, dynamics, and expressive nuance from vinyl playback.

The chassis design features a 10 mm thick slanted aluminum front panel, 1.6 mm copper-plated steel base and cover, and heavy metal feet to suppress vibration and magnetic distortion. Each channel has its own rigid housing and power supply. A newly designed built-in MC transformer with split winding uses PC-TripleC copper for the secondary winding, aimed at improving signal integrity.

On the functional side, it provides three input terminals (MM/MC switching for each), with Inputs 1 and 2 supporting balanced (XLR) input. A 2nd-order (two-stage) CR low-cut filter is included to suppress subsonic noise and protect speaker motion. Users can switch between three playback curves (RIAA stereo, DECCA Mono, and Columbia Mono. A 30-second degauss circuit demagnetizes MC cartridges with metal cores.

The EA-550 has been awarded multiple honors including the Ongen Publishing Audio Excellence Award 2020 (Gold & Silver), MJ Technology of the Year 2019 (Honorable Mention), and Stereo magazine Best Buy Components 2020 (Phono equalizer over ¥500,000, 3rd place).

Features

• Dual-chassis, monaural boxed design with independent L/R units
• Built-in MC transformer with split winding, using PC-TripleC copper on secondary
• Three inputs, with MM/MC switching for each; Inputs 1 & 2 support balanced (XLR) operation
• 2nd-order CR low-cut filter (non-feedback) to attenuate subsonics without degrading music
• Playback curve switching: RIAA (stereo), Mono1 (DECCA), Mono2 (Columbia)
• Degauss circuit (~30 s) for MC cartridges with metal cores
• RIAA network: 1% metal-film resistors and silvered mica capacitors
• Signal path: ELNA SILMIC electrolytic capacitors, metal-film resistors
• Power circuit: Rohm SiC diodes, Nichicon high-grade electrolytics, ELNA SILMIC II decoupling caps
• Low-noise Zener diodes and shunt regulators (no feedback) for fast, ultra-low noise power
• Four R-core transformers (positive/negative for each channel) with low leakage flux

Specifications

Form: V-I / I-V conversion type full symmetrical non-feedback equalizing amplifier

Inputs: MM, MC

Input Sensitivity (MM/MC): 2.5 mV, 0.13 mV

Suitable Cartridge Output Impedance (MM/MC): 47 kΩ or less; 1.5 to 40 Ω

Gain (MM/MC): 38 dB, 64 dB

Input Equivalent S/N Ratio (MM/MC): −120 dBV, −140 dBV

Rated Output Voltage (1 kHz): 200 mV

RIAA Curve Tolerance (20 Hz–20 kHz): ±0.5 dB

Power Consumption: 10 W (per channel, 100 V 50-60 Hz)

Dimensions (Each, WHD): 8.31" x 3.66" x 14.17" (211 x 93 x 360 mm) 

Weight (Each): 12.1 lb. (5.5 kg)