Усилители мощности моно — Audio Note Ankoru/II

The Ankoru/II is a monoblock valve power amplifier from Audio Note UK, sold as a pair with one chassis per channel and built around the 211 directly heated transmitting triode. Audio Note says the circuit and topology follow those of its Gaku-On monoblocks, with one decisive difference - where the Gaku-On winds its transformers in silver, the Ankoru/II uses high-purity copper. The company states that it developed the design for sonic results rather than for a measured specification sheet.

Key specs that matter

Each monoblock delivers approximately 45 W in pure Class A, and Audio Note gives that rating for both 4 ohm and 8 ohm loudspeakers. Signal enters through an XLR balanced line input with an impedance of 2.4 kohm. Channel balance between the two units is held within plus or minus 0.3 dB. Every chassis measures 305 mm high by 305 mm wide and 640 mm deep, and each amplifier weighs 37.5 kg. Mains input can be set for 100-120 V or 220-240 V at 50/60 Hz, and buyers choose a top plate in plain anodised aluminium or a black anodised finish.

Engineering and use context

Two 211 triodes work in parallel single-ended mode in each chassis, so the output stage has no phase splitter and no push-pull pair. A single 6V6GT drives them, and rectification is handled by two 5R4WGB valves per unit rather than silicon diodes. The amplifier meets every criterion of Audio Note Level 3 - Class A bias throughout, no feedback loop, a single-ended output, valve rectification, directly heated triode output valves and the brand's standard of materials and parts. Each 211 has a locating pin on its base that must line up with a rib in the socket, and Audio Note suggests professional fitting whenever an owner is unsure. Each unit has its own IEC 320 mains inlet with separate fuse holders, and Audio Note asks users to turn the monoblocks on last and off first, with the preamplifier volume set to minimum at switch-on.

Pairing

The obvious source is a line stage fitted with XLR outputs, although the Ankoru/II also accepts a single-ended connection. The fairly low input load calls for a preamplifier that is comfortable driving that value, which Audio Note line stages with sub-10 ohm output impedance manage easily.

Alternatives

Audio Note also builds the Conquest, a mono amplifier that uses two paralleled 300B triodes per chassis for 18 W RMS.