MASS-Kobo Model 433

The MASS-Kobo Model 433 is M. Masuda's mid-tier fully balanced desktop amplifier, inheriting the sonic character of the legendary Model 406 and the high-end 394II, and combining it with the output circuit of the Model 402 used by NHK Japan as a broadcast reference amplifier.

Type and Technology

Fully balanced desktop headphone amplifier, solid-state. Balanced XLR input with +4dBm/-10dBm reference level selection and unbalanced RCA input. Balanced XLR4 and single-ended 6.35mm TRS outputs. Worldwide power supply (AC100-240V). Compact and lightweight by MASS-Kobo standards. Made to order in Japan.

Sound Character

Rich, low-distortion, and immensely musical. The 433 is the amplifier that customer after customer returns to call a revelation, instruments appear with a tangibility and presence that transforms familiar recordings, and the sense of stability and authority across the full frequency range is immediately apparent. A headphone amplifier that makes every headphone in the chain better.

Build and Finish

Built individually by M. Masuda to his exacting specifications. Each unit is made to order with a production time of approximately 1 to 4 months. Worldwide power supply (AC100-240V). Compact chassis at 232 x 210 x 48mm.

Best For

Audiophiles who want the MASS-Kobo sound at a more accessible entry point than the 465, and those pairing with demanding headphones including the Final D8000, HiFiMan Edition X, and similar high-performance planars and dynamics.

What's in the Box

• MASS-Kobo Model 433 headphone amplifier
• IEC power cable

Please note: This is a made-to-order product. Production time is approximately 1 to 4 months from order. No cancellations are accepted after an order is placed. Custom duties are the responsibility of the customer.

Specifications