@drrnc2 I will say my Kit 1 was built in 2010, and I've considered changing caps out of sheer OCD. If it was 20+ years old it would be the first thing I would do. I haven't done it yet, but someday I will. I have the AN copper film caps in mine. I will replace to the AN Silver capacitors when needed. They are pricey, but im sure worth it. Ive actually gone all out on my Kit 1 tweak wise. If anyone's interested ill give a list of things done to the amp, all of which has significantly helped the sound of the amplifier. The only things I see left are better ccore transformers and the silver caps.