@viethluu
A subtle nuance to your comment above regarding your Mac preamp. I’ve owned a few Mac preamps through the years. They are feature rich, inoffensive, reliable and trustworthy. They commit no major sins, however, yours interfaced well with Pass Labs NOT because the Mac preamp is universally versatile but because Pass Labs amplification is quite forgiving in that regard.
There are fans and foes of every type of gear manufactured; past, present and future. Mac is a solid business, Ampzilla’s business strength is for you to decide. Formerly bankrupt companies (or those for whom that might be a fallback plan) are difficult to value. I recognize I keep it pretty simple for my amplification choices and I’ve owned alot of great gear. I prefer non-gimicky reliable and beautiful sounding amplification. I don’t have any qualms admitting that I prefer what I prefer and that usually involves vacuum tubes. Horses for courses right?
Have you considered another Pass Labs amp? I believe the Pass Labs amps are reasonably agnostic regarding preamps...which wasn’t an accident but in fact a design goal. My 2 cents on the topic with a 2 cent discount.