Designed and handbuilt in Boulder, Colorado—the 5 series has withstood the test of time as ultra-reliable, reference quality gear that has been heralded by reviewers worldwide for its superior musicality. Adhering to our philosophy of upgrading rather than obsolesence, each of the 5 series products receives perodic upgrades reflecting significant technical improvements we have discovered through our continued reasearch and developement. Every product in the 5 series is designed for a life time of musical enjoyment. Featuring Ayre's Double Diamond output stage, our exclusive EquiLock circuitry, and a Shallco solid-silver contact switch for gain control, this fully-discrete, fully-balanced, zero-feedback integrated amplifier provides a complete solution for your modern music system. The key to perfecting the AX-5 was to incorporate the Variable Gain Technology (VGT) of the award-winning Ayre KX-R preamplifier into the power amplifier section. The addition of ultra-transparent FET input selector switches completed the transformation of a basic power amplifier into a compact one-box solution which will become the heart of your high-performance audio system.