Mono X Power Amplifier (Pair) plus WiiM Ultra (Space Grey)

Not long ago, building a truly high-power amplifier meant making real compromises. To deliver 350 watts into 8 ohms and 700 watts into 4 ohms, you needed enormous power transformers, vast electrical storage, and acres of heat sinking. Efficiency was poor, heat was relentless, and without fans, the only solution was sheer size and mass. The result was an amplifier that was heavy, expensive, and often large enough to sit on the floor as a statement piece. Some sounded wonderful. Others less so. But they all shared one thing: brute force came at a very high cost. Then things began to change. Forward-thinking engineers started asking better questions. Could power be delivered more intelligently? Could efficiency and sound quality finally coexist? Early designs showed promise but fell short. They ran cooler, were smaller, and more affordable, but something was missing. The music felt constrained—slightly off—never quite matching the emotional impact of the best traditional designs. For a time, it seemed like progress had come with a permanent trade-off. That ceiling finally broke. Over the last decade, leading engineers revisited long-held assumptions and challenged the rules that had defined the category for years. They looked backward as much as forward, drawing insight from the industry’s own past and from advances made in modern DAC designs. With this broader perspective, everything came into clearer focus. The long-promised benefits of modern amplification—efficiency, power, and precision—could finally be achieved without sacrificing musicality. Which brings us to today. One of the pioneers in this field has created an amplifier platform that delivers an extraordinary combination of prodigious output, remarkable transparency, low heat, exceptional reliability, and realistic cost. We were so impressed by what we heard that we built it into three separate products, including the Mono X. The Mono X is the purest and most powerful expression of that achievement. It is designed to drive any speaker load with complete ease and unwavering authority. No strain. No noise. No drama. Just effortless music and total control, revealing exactly what’s in the recording—nothing more, nothing less. It is the most complete and uncompromising power amplifier we have ever made and, in our view, one of the finest power amplifiers available at any price. We have compared it directly with some of the most respected amplifiers from both today and the past. None outperforms it. In fact, many are exposed by the comparison. Massive chassis, towering heat sinks, and extravagant metalwork are sonically outclassed by an amplifier that is smaller, cooler, and vastly more efficient. Some competitors do not even make it through the test, shutting down when asked to keep up. Ask anyone who owns a pair of Mono X power amplifiers, and you will hear the same story. The Mono X does not flex with size, weight, or ornate metalwork. It flexes with absolute power, complete control, and uncompromising sonic honesty. Spend your hard-earned money on performance, not pretense.