Fosi Audio K7 or K5 PRO DAC Amp HiFi Gaming Desktop 4.4mm Balanced 2100mW Ultra
K7 – Single‑ended (3.5mm) : 600mW @ 32Ω; Balanced (4.4mm) : 2100mW @ 32Ω. Bottom line : The K7’s balanced output (2100mW) is overwhelmingly more powerful, capable of driving most high‑impedance, hard‑to‑drive audiophile headphones.