Sugden Audition Preamplifier/Power Amplifier (6/99)
Of the traditional stalwarts of British hi-fi, few exemplify the heritage better than J.E.Sugden. Little known outside the circle of those who really care about such things, Sugden amplifiers are nevertheless classics of their kind. Almost every day I use a P51 power amplifier that must be around 30 years old and whose ClassA design inspired more recent models such as the Audio Innovations Alto that took the hi-fi world by storm a few years ago. It runs hot enough at idle to damage its own components when left switched on around the clock but when working normally delivers a smooth and accurate sound that should be the envy of many modern designs.
The heritage lives on and still in Yorkshire, albeit in a different idiosyncratically named town. My P51 was built in Cleckheaton; Sugden today resides in the town of Heckmondwike, no less redolent of moors and mills. There is still a Pure Class A range Ð the A21a series Ð maintaining the company's links with what it acknowledges to be its classic sound. Alongside it is not only a top-end Masterclass series but the much more 'real world' Audition range, comprising a couple of integrated amplifiers and the pre/power combination under consideration here.
Sugden's attachment to its history goes further than mere sentiment. The amplifiers are still hand built, with each finished unit the responsibility of one assembler. Sugden is proud of the fact that five key assembly team leaders have a total of 100 years' experience with the company and clearly regards computer-aided design and robotic construction techniques with healthy suspicion. That is not to say that the designs themselves are dated: the styling is distinctive and modern and the electronics has clearly moved with the times. The specifications are in the top league and, while there is no trace of snake oil, Sugden clearly sets much store by careful component selection and exhaustive listening tests.
The Audition 'Pre-amplifier' is a further development of Sugden's AuditionC integrated model, sharing many of its features and adding some upgrades. Various options are available to suit different operating preferences and system set-ups. The basic model has four identical line inputs and two tape circuits, with controls for volume, balance and source selection. There is an optional factory-fitted phono board, configurable for MM or MC cartridges, and motorized remote control of the volume can beadded with a handset that will alsocontrol RC5-equipped tuners, CD players and other components. The most interesting option of all, however, is what Sugden chooses to call Equalisation rather than mere tone control.
Most tone control circuits leave the midrange untouched, adjusting only the frequency extremes Ð typical turnover frequencies are 100Hz and 10kHz. Sugden's versions meet in the middle at 1kHz, tipping the whole range above or below up or down in a linear fashion. This is not to say that it is in any way crude Ð far from it in fact, as the maximum excursion is only 6dB from flat. In its treatment of the whole spectrum rather than the edges this resembles Quad's Tilt idea, with the added refinement that the upper and lower halves can be adjusted separately. The equalization can be bypassed completely if desired, although Sugden has clearly gone to some trouble to minimize any side-effects. The EQ is handled in parallel to the direct signal path and then added to or subtracted from it, which means that when the controls are at their central, flat position the relevant components are effectively out of circuit.
The front panel is logically laid out but the selection switches offer some scope for confusion. The main input selector is a rotary switch with the input labels printed in a straight line above it, making it difficult to work out which it is pointing to. A separate three-way switch chooses between the selected source and either of the two tape returns. This threw me completely for a while since its operation seemed at odds with the labelling Ð which appears to suggest that the centre position is for listening to the source, whereas in fact the left hand position does this, centre selecting Tape 1.
Two pairs of output connectors are fitted at the rear to facilitate the use of two power amplifiers for bi-amplification, the preferred partner being the Audition Power Amplifier. These connectors, like the input phonos, are upside down compared with the norm; that is to say the right channel are above the left channel ones. All are high quality and gold-plated.
The same is true of the 60 watts per channel (into 8 ohms) power amplifier, which sports unusual output terminals that make it particularly easy to insert heavy loudspeaker cables and clamp them securely. The front panel is as bare as one would expect of a power amplifier, but the contoured lines of the preamplifier are carried over to produce an elegantly styled pairing. Both units have a fascia power switch with an associated green LED, these rather dim indicators being the only lights in evidence. The overall effect is of a very restrained sleekness Ð eye-catching to those interested but otherwise blending into the surroundings.
Performance
Put the two units together and the result is a very fine combination indeed. If this is what traditional hand crafting can do then one wonders quite what progress has been made with modern automated technology. There is an assurance in the performance here that inspires confidence in the designers' aims and abilities Ð a solid and complete sound that is entirely without strain. The frequency response figures suggest that in real terms there are no limits, and that is certainly how the spectrum comes across: very flat and neutral and fully extended at the extremes.
Although I am normally quite happy to see amplifiers dispense with tone controls altogether, I was greatly impressed by Sugden's novel equalization circuit. Despite being apparently more extreme than the more familiar configuration, it appears to allow for much more subtle shaping of the sound, and it seemed to me to be a more natural way of making the kind of compensatory adjustments that are occasionally required. The claims of accurate centre detents stand up well, so that the EQ Defeat switch is more or less superfluous Ð there really is no perceptible difference as it is turned on and off, although my inclination is always to disable tone controls when they are not needed.
Equalization on or off, the Sugden Audition system produces a beautiful sound that is a credit to the company's heritage and dedication. It is very reasonably priced, flexibly configured and needs and has more than enough power in reserve for normal listening. This is unquestionably an amplifier of a very high standard indeed
Specification
Audition Pre-amplifier
Maximum output 15V
Frequency response 5HzÐ350kHz (Ð3dB points)
Channel separation 80dB
Signal-to-noise ratio 90dB
Distortion at 1W 0.0085%
Input sensitivity 200mV
UK retail price £549 without EQ; £649 with EQ; Phono board £89; Remote control volume £99
Audition Power Amplifier
Maximum power output 65 watts per channel into 8 ohms
Frequency response 5HzÐ250kHz (-3dB points)
Channel separation 85dB
Signal-to-noise ratio 100dB
Distortion at 1W 0.008%
Input sensitivity 0.88V for 65 watts
UK retail price £549
Manufacturer J. E. Sugden & Co Limited, Valley Works, Station Lane, Heckmondwike, WestYorkshire WF16 0NF
