McCormack vs. Pass Labs

I've EXTENSIVE experience with HANDS ON time with both these amps and the speakers.
First, the X150 is a better amp than the DNA1 delux. It's possibly 75-100% better overal(run from it's balance inputs!..not the RCA's). Then again it's twice the money over the stock DNA1. If you don't have balance outputs from your preamp, then I would suggest trying the DNA1. But if you have balance out's from preamp, and the X150 is in the budget, then I think you should be pleased. If it's a stretch, then the DNA 1 is fine for now, and it's a step in the right dirrection.
OVerall, there's no other solid state amp I can think of that's better for the money than the X150 for most practical purposes.
good luck

if you listen them both, you will understand that you rather wait until you get budget for pass. they're on completely different levels of performance.

The unmodified McCormack's are great products for the money, but out-of-box they aren't in the extreme echelon of great SS amps. The Pass is noticably better in certain areas out-of-the-box.

However, if budget is a concern, I think going the McCormack route is better because of the cost effective upgrades. For an extra $1000, you can eventually upgrade the amp to Rev A which is used as a reference for several magazine and online reviewers. Better yet, for an extra $1000, you can get most of the Gold revisions which basically brings you as good a SS amp as you can buy. (IMO, the jump from Rev A to Gold is just as rewarding as the initial jump to Rev A)

This is the path I took. It was also great to have Steve McCormack personally work on my amps and even tweak the performance to my specific needs. It's these type of experiences that make the hobby even more fun.

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.