A1s refers to the MusicalFidelity A1 pure A-class amplifier from the music fax, with an output power of only 20W (8 ohms). This device is a typical British sound, with delicate and smooth tone Warm and mellow, full of charm, it is a great opportunity to listen to music. The original machine is not very expensive, but its sound is enough to compete with many larger brands of HI-END machines. We After repeated trial listening and comparison, I decided to make it and share it with everyone. The impact of A1 on audiophiles is profound, and for a long time, people believed that The amplifier is a pure A-class sound, and pure A-class must be hot enough to sound good. Because A1 was too successful, the successor models after A1 were A2 and then A3, but their fame It cannot be compared to A1 in terms of status.