Усилители мощности стерео — Audio Note Vindicator

The Vindicator, a two channel amplifier by Audio Note (UK), is a Class A single ended design using the 2A3 directly heated triode in its output stage. Sonic performance rather than measured specification was the stated design target, and Audio Note (UK) offers the model in three current versions - Vindicator, Vindicator Silver and Vindicator Silver Signature - that share the circuit but differ in the grade of parts.

Key specs that matter

Maximum output is 3.5 W RMS per channel into 4 or 8 ohm loads. Input impedance is 100 kOhm at line level, and 250 mV at the input produces full output. Channel balance is +/- 0.3 dB. The valve complement is one 6SL7GT at the input, two 2A3 output triodes and one 5R4GY rectifier. Mains input is AC 100 to 120 V or 220 to 240 V at 50 or 60 Hz, and power consumption is 270 VA. The chassis measures 195 mm high, 205 mm wide and 506 mm deep and weighs 20 kg.

Engineering and use context

The amplifier fulfils the Audio Note (UK) Level 3 criteria, which require an output stage run in single ended Class A with directly heated triodes, rectification by valve and the absence of negative feedback. One 2A3 serves each channel, and one 6SL7GT dual triode covers the input stage for both. The standard Vindicator is the base grade of parts. The Vindicator Silver moves to Audio Note (UK) tantalum film resistors, copper foil signal capacitors and IHiB C-core output transformers. The Vindicator Silver Signature keeps the copper foil signal capacitors and tantalum film resistors and fits Audio Note (UK) SHiB double C-core output transformers. The fascia can be ordered in black acrylic or anodised aluminium, and the top plate in anodised aluminium or black anodised aluminium, so the amplifier can match other Audio Note (UK) components. The single 5R4GY valve handles rectification for the whole unit. Because the upgrades concern parts rather than the circuit, all three versions share the same output, input and physical data.

Pairing

With such low output the Vindicator needs loudspeakers of high efficiency to reach normal listening levels. A line preamplifier with volume control goes ahead of it, and the high input sensitivity means a preamplifier with modest output voltage is enough to reach full output.

Alternatives

The Audio Note (UK) P1 SE Signature is a two channel power amplifier using parallel single ended EL84 valves for 8 W RMS per channel.