The AMG STA-SE incorporates numerous cutting-edge innovations in power amp design. Its exceptional features include a 1M Ohm input impedance, high instantaneous current for efficient power delivery, a >700kHz switching frequency, and a unique combination of Single-Ended Non-Negative Class A module with Double Feedback Class D module, resulting in a powerful 300W mono amp output. The exceptionally smooth sound characteristic of the AMG STA-SE sets it apart from other top NuPrime amps like the AMG One, Evolution STA, and Evolution Two. *Existing AMG STA can upgrade to AMG STA-SE. Please contact your country distributor or service center.