Ran across Skunkie's YouTube channel searching for ACA reviews. I built one several years ago. Decent little amp and learning experience. I've built a few tube kit amps (Bottlehead), one scratch build (1626), and a few headphone amps (SOHA original and Millett hybrids) over the last 20 years. Refurbed my old Vibrochamp and built a Gibson Ga-18T from scratch last year. Currently have a Baby Huey EL34 and Hagerman Clarinet preamp in the queue, along with a half finished diytube st-35 pcb I've had populated for 15 years. I'd love a 300B or 211 but the tubes are just too expensive. My problem is I have such long time spans between projects it's like learning all over again each time! Id really like to explore designing a 6HZ8 spud amp - sort of a more powerful, linear version of the 6197 and super cheap. Anyway, looking forward to getting ideas and learning some more.