The original Musical Fidelity A1, is something of a classic amplifier design. A good, well priced class-a amplifier implementation. However at a mere 25W per channel, it won’t handle the more demanding or less efficient speakers. These MA50 monoblocks, released in 1985 are perfect in this situation. The exact same class-a design (same PCB), with a bigger power supply and both channels wired up in parallel to give 50W per monoblock. Like the A1 (and all class-a amps), they do run hot, so don’t stack anything on top.