Усилители мощности стерео — Audio Note Tomei Kensei

The Tomei Kensei is a stereo power amplifier from Audio Note (UK), part of the Kensei family of power amplifiers that share their circuit design with the company's Ongaku Kensei and Jinro Shochu models, placing the Tomei Kensei between them. It is a single-ended triode design built around the 211 transmitting triode, and it satisfies every point of Audio Note's Level 4 checklist, from feedback-free Class A operation with valve rectification to the grade of parts used.

Key specs that matter

The Tomei Kensei delivers approximately 20W per channel into 4 or 8-ohm loads from one 211 per channel. Input impedance is 2.4 kilohms, full power needs 450mV at the input, with the two channels matched to +/-0.3dB. The valve complement is two 211 output triodes, two 6V6 drivers and two 5R4WGB rectifiers. Maximum power consumption is 200W. The chassis measures 305 x 305 x 640mm high, wide and deep, at 38kg, with an anodised aluminium or black anodised aluminium top plate.

Engineering and use context

The 211 is a transmitting-type triode that runs at a high plate voltage, which allows a single valve per channel to deliver more than twice the power of a 300B stage in single-ended Class A, while keeping the one-device-per-channel simplicity of a single-ended design with no push-pull pair. The circuit runs open-loop and is transformer coupled throughout, with the 6V6 driver stage coupled to the 211 through an interstage transformer rather than a capacitor, as in Audio Note's Gaku-On architecture. The low input impedance indicates an input transformer, which is why the amplifier is intended to be fed from a preamplifier with low output impedance, typically over balanced connections. What distinguishes the Tomei Kensei is its transformer winding - in-house output transformers combine copper primary windings with silver secondary windings, a step between the copper-wound Jinro Shochu and the silver-wound Ongaku Kensei. Level 4 parts include Audio Note tantalum resistors and its own foil capacitors. Two 5R4WGB valve rectifiers provide the high-voltage supply. Given its weight and large valves running hot, the amplifier needs a solid support and generous ventilation.

Pairing

Its output lets the Tomei Kensei drive a wider range of speakers than 300B amplifiers, though efficient designs such as Audio Note's AN-E and AN-J remain the natural match. Its input requires a preamplifier with low output impedance, such as Audio Note's own line stages.

Alternatives

Audio Note's own Ongaku Kensei is the higher-level 211 power amplifier in the same family, with silver-wound transformers.