Musical Fidelity A1 Integrated Amplifier

Musical Fidelity A1 integrated amplifier is an updated version of the original A1 that was released in 1984, still offering the classic look of the original along with even better sound quality and updated features.

The A1 is a Class A amplifier and as these designs tend to run hot, the casework has been designed to act like a giant heatsink. Class A provides a warm smooth sound, similar to valve equipment.

The new version preserves the classic look of the original, although it is a little larger and has improved heat handling. All of the electronic components are modern high-performance devices. The build quality is excellent and the controls have a precision feel to them. There is also now a remote control supplied and the output power is 25 Watts per channel.

Class A amplifier

The output is 25 watts per channel and the chosen speakers should be carefully matched. For example, Musical Fidelity's own 15-ohm impedance LS3/5A as released at the same time are another nod to classic design and recommended pairing, although you can match any other suitable speakers.

Class A amplifiers always have current flowing in the output stage. In the case of the A1, it is 800 mA. They are not as efficient as Class B however there is no crossover distortion. Class A power amplifiers can use a single output transistor or more commonly two. They also need beefy power supplies, as the current demand can be high. Class A/B is the most common type of amplifier. These are a compromise between audio quality and efficiency.

Class A is an aspirational choice that provides a warmer sound and makes the new A1 excellent value at this price point.

Connectivity

in addition to standard RCA inputs for your music sources e.g. streamer, CD transport etc, there is an onboard phono stage is included and is selectable between MM and MC on the back. The volume and input selection are electronic rather than mechanical. The RCA inputs are gold plated.

Unusually nowadays for tape fans there is also a tape loop. Tape is making a comeback with rumours of mainstream manufactures again making good quality cassette mechanisms. There are also several very high end, reel-to-reel decks in production. Master tape recordings are also available on reel-to-reel tape, for the audiophile market.

Phono preamps

There are two main types of cartridges in use at the moment - moving coil (MC) and moving magnet (MM). Moving magnet cartridges have a magnet mounted on the end of the cantilever that holds the stylus. This generates an audio signal by interacting with a fixed pair of coils. They are easier to manufacture and have a relatively high output, of around 5mV.

Moving coil types reverse this with the coils mounted on the cantilever. This has the advantage of reducing the mass, with the result that high frequency reproduction is improved. However, they have a low output that can be lower than 1mV. They also have different impedance characteristics. Hence why the A1 has a gain switch.

The original A1

The original A1 was released in 1984 and was in production until the early 1990s. It was a class A design and the sound was characterized as being more like a valve amp. The original A1 cost £300 in 1991 and the amplifier had various upgrades over the years. With MkII the power was increased to 25 watts. Finally, there was a collectors edition that had an external PSU and an output power of 40 watts per channel.