Musical Fidelity A1
Integrated Class-A amplifier
The Musical Fidelity A1, originally released in 1985, has established itself as a classic in the world of Hi-Fi, known for its exceptional design and performance. Despite its modest power output, the A1 garnered attention for driving challenging speakers in pure Class A, showcasing expertly laid out discrete symmetrical circuitry and high-quality components. Over the years, the A1 has undergone reissues and updates, and in 2023, the original specifications, appearance, and circuits from the 1985 version have been retained.
Fully symmetrical Class A topology
The A1 is constructed around a fully discrete and symmetrical Class A topology, capable of delivering 25W of pure Class A power at an 8-ohm load with a maximum output of 25A. While the power figures might seem low, the dynamic Class A design enables the amplifier to smoothly transition into Class B operation when needed. The power supply has been upgraded with a more efficient "dual mono split rail" transformer, providing independent left and right power supplies for improved power handling and stereo imaging. The updated transformer enhances efficiency, reduces noise and heat dissipation, and features improved regulation and reduced switch-on surge.
Upgraded components
Notable technical enhancements include a new "direct" switch at the preamp stage, allowing bypass of the gain block for reduced gain, beneficial when working with modern or high-output digital sources. The volume potentiometer has been upgraded to a premium ALPS RK series potentiometer, now motorized for remote control convenience.
The A1 features a discrete current-mode input stage for low-noise amplification of MC and MM cartridges, along with automatic input impedance matching for the selected MC input. The phono stage's versatility is further enhanced with increased gain.
The sweet sound of Class A
Despite its lower power, the A1 is praised for its ability to make music with a sweet, warm, full, and exciting sound. It avoids harshness and grain, driving difficult speakers effortlessly and remaining clean up to its power limit. In small to mid-sized rooms with carefully positioned two-way speakers, the A1 creates a beautiful atmosphere around natural instruments. Its oversized heatsinks, essential for operation, define its unique look, combining form and function. In essence, the A1 is not just a powerhouse; it is a true Hi-Fi classic that excels in delivering a pure and simple musical experience, embodying the essence of what Hi-Fi is meant to achieve.
| Measurements | 44 x 6.83 x 28,33 cm |
| Weight (net) | 10.5 kg |
| Digital input(s) | No |
| Input, Stereo RCA | 5 |
| Input, Phono pre-amp | Yes, MM and MC compatible |
| Output, Stereo RCA | 1 |
| Pre-out (stereo) | Yes |
| Tape out | Yes |
| Signal-to-noise ratio | 82 dB |
| Power at 8Ω (per channel) | 25 watts |
| A/B Speaker | No |
| Number of channels | 2 |
| Amplifier type | Class A |
| In the box | Remote control, Power cable, Users guide |
| Power consumption when standby | 0 watts (power off) |
| Power consumption | 130 watts |