Stereo Amplifier

Review: Arcam Alpha 6 Plus Stereo Amplifier

Arcam’s nomenclature always makes life easy, with Alpha denoting the entry level range and numbers within indicating relative status. Thus the Alpha 5 Plus and 6 Plus amplifiers replace the original Alpha 5 and 6, the 6 being a higher powered and slightly more elaborate model than the 5, while the Alpha 6 CD player is a new model altogether, sitting above the existing 5 and 5 Plus in specification.

There is no mistaking the Arcam origins of the new equipment, sharing as it does the familiar elegance and simplicity of style that has become Arcam's hallmark. The Alpha 6 Plus amplifier offers little more than the bare minimum of controls, with the few concessions to the frill-seeker implemented in such a way as not to compromise the standards expected by the audiophile. Thus tone and balance controls are provided, but can be left out of circuit altogether by means of a Direct switch. Even when enabled, the tone controls are among the most subtle you are likely to encounter, offering only 3dB of boost or cut at 100Hz and 10kHz. This tiny range allows only the most modest of corrections to the source signal; those seeking to make radical alterations lo the original to match their idea of what it should sound like (although 1 have never understood why anyone would want to) should look elsewhere.

A good number of inputs are provided, four of them being electrically identical line-level inputs with suitable labelling (including video-sound channels only of course) and the fifth a dualpurpose connection switchable between line-level and phono preamplification. The selection is made with a small recessed pushbutton on the rear panel and is intended as a set-and-forget function rather than a readily available choice; the point is that unlike many current designs the Alpha 6 Plus retains the facility to play vinyl records without external preamplifiers. Improvements to this phono stage, which is designed to accept moving-magnet cartridges, constitute one of the enhancements of the new model.

In addition to the inputs offered by the rotary switch there is a Tape switch allowing the usual off-tape monitoring from a three-head recorder. Note that there is only one input selector switch, so that the recording outputs always carry the signal to which you are listening. A duplicate pair of Record connections allows a second machine - DAT, MD or video perhaps - to be permanently connected, although it has no corresponding monitor loop and its output must return through one of the standard inputs.

Two pairs of loudspeaker terminals are provided, using Arcam's familiar reassuring shrouded binding posts, and the first pair is permanently connected to the output devices in the interests of signal integrity (there are no loudspeaker selector switches or headphones socket contacts in its path). The second pair is connected via a front-panel switch, allowing those who envisage frequent listening to headphones to use this output and mute their loudspeakers when required.

Although no handset is supplied with the amplifier, remote operation of its volume is possible from the controllers accompanying other items such as the CD players. These carry a pair or nudge buttons which activate the amplifier’s motorized volume control -no electronic attenuation or switching is used.

Internally as well as externally the design and construction is of the high order one expects from Arcam, marked by simplicity and clarity. The changes constituting the upgrade from the 6 to the 6 Plus include a new toroidal mains transformer with improved screening and other uprated components, as well as gold-plated connectors throughout. The gold plating extends to the internal terminations of the phono sockets and the loudspeaker outputs, the latter incorporating substantial solid bars from the PCB to the terminals. To give an idea of how thoughtful the design is, there is a spare output fuse mounted in a holder on the board, and for the service technician there are instructions as to how the amplifier should be disassembled printed on the PCB itself.


Measurements confirmed an audible difference I had detected between the Direct signal path and the route via the tone and balance controls; this turned out to be a straightforward level difference of 0-5dB across the range, the direct signal being the higher. Frequency response with the lone controls set nominally fiat at their detents was unaffected, and showed a range extending well above 100kHz with less than 3dB reduction, and at the lower end no deviation from flat beyond the scope of my test equipment. The central position for the balance control was also exactly in line with the Direct balance, although the meter showed almost 1dB difference between channels with or without the balance control in circuit, which was also just audible although not problematic.

Whatever their size, rating and price, Arcam amplifiers have a knack of delivering a consistently satisfying, complete sound, and the Alpha 6 Plus is no exception. Never have I encountered such a sense of effortlessness from such an apparently modest box. nor such clarity and spectral extension, all of which would be creditable from a much more expensive, esoteric amplifier. The sound produced by the new Arcam is remarkable in its neutrality, depth and life, and reminded me once again why I have a tendency to regard Arcam as a yardstick by which to measure others in a given price bracket.

Arcam has to my mind quite simply got it right, and it is good to see new models simply refining its established designs rather than attempting to usurp them with unnecessary new ideas. The Alpha 6 Plus shows what can be done for the money when the priorities are right and the design is sound. It offers simple, subtle facilities which are useful when required and which can be dispensed with when not, and delivers a performance as accurate and rewarding as you are likely to find for the price.

I approached this amplifier with high expectations which were not disappointed, and once again I have no hesitation in recommending it warmly.