Усилители мощности стерео — Audio Note Jinro Shochu

The Jinro Shochu, a two channel power amplifier made by Audio Note (UK), is presented by its maker as a Class A single ended design whose output stage relies on the 211 triode. Its circuit is shared with the Ongaku Kensei and Tomei Kensei amplifiers, but the Jinro Shochu uses copper for every transformer winding rather than silver or a mix of silver and copper. Its designers set sonic results ahead of measured figures as the goal.

Key specs that matter

The amplifier delivers approximately 20 W per channel into 4 or 8 ohm loads. Input impedance at line level is 2.4 kOhm, and a 450 mV signal gives full output. Channels are matched within +/- 0.3 dB. The valve complement is two 5R4WGB rectifiers, two 211 output triodes and two 6V6. The mains section accepts AC 100 to 120 V or 220 to 240 V at 50 or 60 Hz, with a maximum consumption of 200 W. The chassis is 305 mm high, 305 mm wide and 640 mm deep, and the unit weighs 38 kg.

Engineering and use context

The amplifier meets all the Audio Note (UK) Level 3 criteria - Class A operation through one single ended output valve per side without negative feedback, a valve rectifier and a directly heated triode. Level 3 components are used throughout, including Audio Note (UK) Copper Foil capacitors and output transformers designed and wound in house with copper wire. The inputs are a pair of XLR balanced input sockets placed on the left hand side panel, while the speaker terminals are on the back. The valve sockets use locating pins so that each tube fits in only one orientation. The 211 valves are the main power tubes of the output stage, and the two 5R4WGB rectifiers go in the left rear positions. The power amplifier should be powered up after every other component and powered down before them. The top plate can be ordered in anodised aluminium or in black anodised aluminium, and Audio Note (UK) notes that specifications may change as part of its ongoing development work.

Pairing

Balanced XLR sockets require a preamplifier with XLR outputs, while the modest output suits loudspeakers with enough efficiency for that power. Because the chassis is large and heavy, the supporting shelf must carry its full weight.

Alternatives

The Audio Note (UK) Vindicator is a more compact stereo model meeting the same Level 3 criteria, rated at 3.5 W RMS per channel from 2A3 triodes.