Stereo Amplifier

Review: Musical Fidelity Elektra E10 Stereo Amplifier

In December 1994 reported on the first of Musical Fidelity's Elektra range, the £600 E100. This junior model comes in at half its price - £299-95 to be precise - and is soon to be joined by an identically priced matching tuner and a CD player.

Elektra E10 retains the same 440mm width of the senior model and a similar depth but the height is reduced by a third, making for a much preferable appearance in my view; the other components will be of similar size and finish. Although they readily succumb to finger marks I find the black mirror finish front panels, originally seen on the Aura range, to be a most attractive alternative to Japanese standard black. Musical Fidelity has further enhanced the frontal appearance with shiny domed knobs which complement the panel, and these are set off with neat light gold legends. A tiny red LED at the edge of each knob indicates its position and also shows that the amplifier is powered up.

The remainder of the casework is black vinyl-coated sheet steel with a fine wrinkle finish; four rows or ventilation slots run from front to back on the top surface. The two on the left are immediately above the output transistor heatsinks and as these are MosFet devices they are run with a fairly high standing current, so care must be taken to leave them unobstructed. The ubiquitous drum feet, with gilded trim, raise the unit sufficiently for air to flow through matching slots in the base.

Although of minimalist design, eschewing tone controls and the like as is today's fashion, the E10 does include a phono stage for magnetic pickup cartridges and has provision for two recorders, one of which, if suitable (e.g. a three-head cassette deck), can be monitored via a small push-switch on the front panel. A similar switch at lire left turns the unit on and off. Moving clockwise around the E10 reveals an unusual placement in the left side of the case - a standard jack socket for headphones, the use of which automatically cuts off the loudspeakers. Further exploration reveals a fijsed IEC mains connector (lead with moulded plug provided), two pairs of stout loudspeaker terminals and eight pairs of gold-plated phono sockets to cope with all the usual auxiliaries.

Internally the Elektra E10 layout has a toroidal power transformer at the left of the vertical aluminium heatsinks; these carry two parallel complementary pairs of plastics encased MosFets (IRF540 and IRF9540) and their bipolar drivers (TIP31C). The extensive remaining area supports a large printed circuit board which is sparsely populated with the remaining components, a pair of 10.000 pF power supply electrolytic capacitors the most prominent among them. All the early stages of the power amplifier back to the line inputs use discrete transistors and the only integrated circuit appears in the phono stage which incorporates an NE5532 dual operational-amplifier. The latter is situated in the far right corner immediately behind the phono input sockets and well away from the remainder of the circuit. Musical Fidelity makes a feature or star earthing which refers all the signal returns to a common point at the junction of the positive and negative power capacitors, thus avoiding unwelcome circulating currents.

Performance

On test the E10 produced an excellent set of results. With both channels driven it could not quite produce the claimed output, which I now presume applies to a single channel; however, with twin S ohm loads it put out 38 watts into both and what is more held that power over the entire frequency range from 20Hz-20kHz, This is a broad-band design and I found the overall response to be very fiat, falling by 1dB at the extremes of 5Hzand 35kHz. An input signal of 310mV was required to drive to clipping level, just below which distortion was a mere 0,01%. With a line input suitably loaded with 200 ohms the unweighted signal to noise ratio was 97dB at any position of the volume control and from the phono input at maximum it was still 68dB. Crosstalk was negligible over most or the range at about 64dB but it started to climb at 5kHz, reducing to 55dB at 10kHz and 48dB at 20kHz. At these higher frequencies it was considerably distorted, the waveform varying with volume control setting, suggesting unwanted coupling between conductors on the circuit board. The RIAA correction was accurate to within 0,5dB at the treble end and fell midway between the original and revised IEC curves in the bass.

The E10 is a fine example, with a rich sound, full of detail and with a smoothness about the treble which is not too often accomplished in the £300 bracket. Perhaps it lacks something of the analytical neutrality of the very exclusive upper strata but right up to its overload point it gave immense musical pleasure to this pair of ears. Perhaps because of its paralleled output transistors and a relatively small amount of overall feedback it showed a remarkably effective sense of power and weight on a recent organ recording I made in Winchester Cathedral. But it would be invidious to pick on one facet of this excellent newcomer to the popular £300 price break. If the companion tuner and CD player are of comparable quality the set of three will strike another telling blow for the superiority of separates.