Preamplifiers — Musical Fidelity M8SPRE

The M8sPRE is a fully balanced preamplifier from the British maker Musical Fidelity and the control unit of its M8 series. Its circuitry is pure Class A throughout, and unlike designs that only place balanced sockets around a single-ended core, it keeps the signal balanced from input to output. The maker gives it very high input overload margins and the ability to drive practically any power amplifier.

Key specs that matter

Eight inputs are fitted - two balanced XLR line inputs, five RCA line inputs and an RCA phono input with a switchable MM/MC stage - plus a trigger input. Outputs are one RCA pre out, one XLR balanced pre out, one RCA fixed output for recording and a trigger output. THD plus noise is under 0.005% single-ended and under 0.004% balanced, and the maker quotes an A-weighted SNR above 118 dB. Frequency response is +0, -1 dB from 5 Hz to 100 kHz. The chassis measures 440 x 162 x 400 mm and weighs 17 kg unpacked.

Engineering and use context

Power comes from two 350 VA mains transformers, one for each channel, and every stage of each channel has its own regulation circuitry, which keeps the stages isolated from one another. The maker also gives a stereo separation of 96 dB at 1 kHz and a -3 dB bandwidth point at 75 kHz. Home theatre bypass is provided on one balanced and one single-ended input, so a surround processor can route the front left and right signals at unity gain while the stereo system keeps its own volume control. The fixed RCA output works as a tape record feed, and the trigger connections let the preamp turn a power amplifier on and off with it. The unit is offered in black and silver finishes.

Pairing

Within the same series the M8s-500s stereo power amplifier is the matching partner, sharing the 440 mm width and offering both XLR and RCA inputs, and it provides 500 W per channel into 8 ohm. A balanced connection between the two keeps the signal balanced end to end. The MM/MC phono input accepts a turntable directly, and the pair of balanced inputs suits sources such as CD players and DACs with XLR outputs, while the five RCA inputs leave room for a tuner, an auxiliary source and further line level components. With the very high input overload margins quoted by the maker, sources with a high output level can be connected without the input stage clipping, and the preamp is rated to drive long interconnects to its partner amplifier.

Alternatives

The Musical Fidelity M6s PRE is a smaller balanced Class A preamp in the M6 series, with two XLR and four RCA line inputs, an MM/MC phono stage and a USB type B input, weighing 11.4 kg.