Усилители мощности моно — Audio Note Ginrei

The Ginrei is a pair of mono valve power amplifiers from Audio Note (UK), each chassis running two 211 transmitting triodes in parallel single-ended Class A. Its circuit design and topology follow the company's Gaku-On amplifiers. The main difference lies in the output transformers - the Gaku-On uses silver wherever possible, including all windings, while the Ginrei has copper primaries and silver secondaries. The Ginrei meets every point of Audio Note's Level 4 checklist, a list that asks for Class A bias with no negative feedback, single-ended output, valve rectifiers, directly heated output triodes and a set grade of parts and materials.

Key specs that matter

Maximum output is about 45 W per channel into 4 or 8 ohm loads, with separate 4 and 8 ohm speaker connections. The only input is balanced XLR at 2.4 kOhm, and channel balance is held within 0.3 dB. Per chassis the valve line-up is two 211 output triodes, two 5R4WGB rectifiers and one triode-connected 6V6GT driver. Each amplifier stands 305 mm high and 305 mm wide, runs 640 mm deep and weighs 37.5 kg, so a pair comes to about 75 kg. Mains input is 100 to 120 V or 220 to 240 V at 50 or 60 Hz, and maximum consumption is given as 200 W.

Engineering and use context

Two 211 triodes share one output transformer in parallel, which lets the Ginrei reach its rated power while keeping the single-ended topology instead of moving to a push-pull stage. The 211 is a directly heated triode, one of the Level 4 requirements. Each channel has its own valve-rectified power supply because the two monoblocks are fully separate. The signal path contains no coupling capacitors at all. There is no volume control, no source selection and no RCA input, so the amplifiers depend entirely on the preamplifier for level and switching. They must never be switched on without a loudspeaker load connected, and the four 211 valves and rectifiers give off a lot of heat, which calls for open ventilation and shelves deep enough for the long chassis.

Pairing

A preamplifier with balanced outputs is required, such as the Audio Note M6, whose line stage includes a balanced output circuit. Loudspeakers should be matched with care, and efficient designs make best use of the available power.

Alternatives

The Audio Note Kassai is a Level 4 pair of single-ended mono amplifiers built around 300B triodes and rated at 18 W per channel.