@oddiofyl That's what I am leaning towards. Much cheaper than Decware, which I also really liked, PTP wired, and US made, as opposed to PL, which is also great from what I read.
Which preamp are you using with them, if anything?
Also, PL says they have protective circuit to avoid damage when tubes fail as well as tube decline indicator. Does QS have protective circuit? I know it has LED biasing indicator. Does this work as a early tube failure indicator?
Thanks