Sugden A21SE

Sugden A21SESugden needs no introduction; anyone with more than a passing interest in audiophilia knows the A21 is a series of English amplifiers which started in the mid nineteen sixties with an 11 watt solid-state bipolar integrated amplifier. It was produced over a period of time in three series of models, then the A21a went on to become a nineties benchmark; a specialist product that promised clarity at the expense of all else…

The common thread which runs through Sugden’s A21 amplifiers is the pure Class A output stage operating with current feedback and a single voltage rail. As the manufacturer says, the potential of this output configuration is limited only by the preceding gain stages of the overall amplifier. The SE brings increased output power, wider bandwidth, reduced distortion and greater load tolerance to the party and adds remote volume control, relay switched input signals and a completely new casing. The new line stage amplifier with a cascode input stage, current feedback, with the input and output in phase is said to give all the benefits of high input impedance, high voltage gain in its first stage, low distortion with wide bandwidth, low noise and low output impedance. The line stages are supplied by their own current shunt power supplies driven by a separate transformer winding.

Many people have never heard pure Class A operation, and often believe it to be super-smooth and ‘valve-like’. It is neither; rather it’s best described in terms of what it’s not. It’s not grainy, mushy, grey, sat-upon, nervous or frigid like most transistors, and it’s not soft, vague, euphonic, coloured and loose like poorly implemented (i.e. most) valves. Rather, pure Class A, and specifically Sugden’s implementation thereof, sits in a magical ‘other world’ of glass-clear, incisive and neutral-to-a-fault amplification…

The interesting thing is that, despite its lack of absolute power, it’s able to go from super quiet to very loud with dizzying speed. Dynamics are amazing. The sound of a strongly hit snare pushes out of the mix with stunning clarity, and then fades away as instantaneously as it first came, and then comes back again on the next beat with the same visceral impact – and, importantly the Sugden strings this together with such aplomb. Each four bar phrase is brilliantly accented, pushing the music along powerfully.

Rhythmically and dynamically then, it’s a revelation – but there are other amplifiers that do this brilliantly too. However, at this price (or anywhere near it), I’ve never heard one that has such clarity. The A21SE is so neutral, so self-effacing and ‘glass clear’ that you can hear every last harmonic on the squelch of Walter Becker’s analogue synthesiser, every last resonance in Donald Fagen’s voicebox. The midband is revelatory then, but bass and treble are no poor relations. The former is super-fast, super-taut and yet just bounces along with ‘valve-like’ aplomb. It invests the track a wonderful ‘naturalness’ which makes complete sense. Treble is lovely too – but not warm or sweet, just neutral. Gone is the fizz, zing, imprecision, haze – and in its place is something that sounds like real hi-hats being struck on a real drum kit, right in front of you. The detailing is disarming, so fast and yet so unobtrusive, undistorted, uninvasive.

Downsides? Few that I can think of, aside from a cheap-as-chips plastic remote control, and the fact that the controls don’t move with a wonderfully smooth, precise gait.. The A21SE has the feel of an extremely well made hand built kit – which I suppose is what it is – but lacks that luxuriously silky tactility owners of high end Japanese fare take for granted. There’s also the fact that despite its useful power hike, the A21SE still doesn’t like tricky loads. Match with a nice, easy-to-drive set of speakers like the Mission 752 then, and this a lovely solid-state seducer!

One comment

  1. Pingback: Sugden Masterclass IA-4 |

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