McCormack vs. Pass Labs

Yeah but... After you spend the extra dough for the revisions you've surpassed the cost of a used X-150. What's the sense in that? The beauty of the Pass is that it is the best it can be right out of the box. There is no such thing as Pass amp upgrades. That should tell you something about the relative quality of the two companies. Open the top of an X-150 and all the circuitry you will see is a tiny jewel like cluster of resistors and caps that just govern the switching and lights. The actual signal path runs direct current throughout with not a cap, nor a resistor along the way, other than the power mosfets. It is a two stage single ended mosfet feeding a bank of high efficiency Hexfets second stage. The simplicity results in stunning dynamic swings and nonfatiguing limitless highs. The mids are sweet and clear. The Bass is a musical bass, none of that high feedback unnatural bone jarring stuff.