Интегральные усилители — Audio Note Ongaku

The Ongaku is a stereo SET amplifier with integrated controls, made by Audio Note (UK), the family-owned company run by Peter Qvortrup near Brighton, England. Its output stage uses two 211 directly heated triodes, also known as the GE VT-4C, and operates in pure Class A with no global feedback, drawing its high voltage from valve rectifiers. In the United States the Ongaku carries a price of USD 168,630.

Key specs that matter

The rated maximum is roughly 20 W per channel into either 4 or 8 ohm loads. The line inputs have an impedance of 100k ohm and require 450 mV for full output, with the channels matched within 0.3 dB either way. Audio Note gives the dimensions as 305 mm high, 305 mm wide and 640 mm deep, and the weight as 48 kg. Mains input covers 100-120 V or 220-240 V at 50 or 60 Hz, and maximum power consumption is 200 W.

Engineering and use context

Audio Note lists a complement of two 5R4WGB rectifiers, the two 211 output triodes, one CV4068 and one 6463. Current production uses Audio Note 4242E output valves of the 211 type, made for the company by Psvane, with a new old stock Telefunken 6463 as driver and a new old stock Amperex 12AU7 at the input, while the rectifiers in current units are JAN CAHG 5R4WGA types. All internal connections are made with Audio Note (UK) silver wire, and the resistors are the company's non-magnetic two-watt tantalum types throughout. Black Gate electrolytics serve the power supply and Audio Note (UK) silver foil capacitors handle signal coupling. The transformers are designed in house, with the driver and output transformers fully wound in silver on AN-Perma 50 nickel C-cores, while Audio Note specifies the mains transformer as copper wire on a UHiB core. Source selection runs through a TKD four-position switch, and volume is set by an Elma stepped attenuator fitted with Audio Note tantalum resistors.

Pairing

The power of a single-ended stage still points towards loudspeakers of reasonably high sensitivity. The four-position selector accepts four line sources, and with line inputs only, vinyl replay depends on a separate phono stage placed ahead of the Ongaku. Speaker cables attach to four silver-plated binding posts.

Alternatives

The Audio Note Meishu Tonmeister is a more compact Audio Note integrated, using 300B output triodes and rated at about 8 W per channel.