The A1 ("Crosby"), is a versatile high efficiency class-D stereo power amplifier which matches well with the Young MkIII, both in size and sound. Its clean power is enough for most speakers, while its drive capability can be improved by setting it in bridge mode. In this case, the Crosby becomes a powerful mono-block amplifier; two amps in bridge mode can drive virtually every speaker, be it an array of dynamic drivers or an electrostatic panel. The A1 can be attached to most preamplifiers, not only to the Young MK3. The new A1 is provided with both single-ended and balanced inputs, plus trigger input and pass-through. Thanks to its proprietary class-D design, it is virtually impossible to destroy, all overload situations are reported on the front panel prior to reset.