@hilde45, only Mike @ QS could confirm warranty info for you for yours.
re: caps
I’ve come across 50+ Quicksilver amps and QS owners with upgraded tubes and upgraded coupling caps in them. The bones of the amps are great! The design, transformers, chassis, layout is an amazing value. Pop over to AudioAsylum, AudioCircle, DIYAudio sites to learn more. Some builder/members mod them over there.
Keep in mind these QS monos are built at a price point, and yet the foundation is there. However, if QS offered high end tubes and top-shelf coupling caps in them, the amps would list for 2x the price new or more. The stock caps are pretty good, a bit veiled over to me, yet do have a nice midrange tone in stock form. I wanted more.
When you install really good input/driver tubes, followed by top-shelf coupling caps, they can compete with amps at 2-3x the price new. Following a hunch, wanted to prove they could be taken to a new level to compete with my other amps. Sure enough.
My QS monos sounded good in stock form and yet could not compete with any of my former upgraded Cary amps. After a year of listening to my QS Mono 120s, and after lots of tube rolling first six months, I finally went to top-shelf coupling caps. Wow, now they sound fan-friggin-tastic, more transparent, layered, added harmonics and three dimensional. The added reality of the change in tone and musicality alone was worth it. As soon as I did it, it was "there", and jumped again after full cap burn-in and settling occurred. Very pleased now. YMMV, Good Luck.
