A flag, or a ton of flags, won’t have any perceptible impact. They’re likely just about acoustically transparent.

Yeah…don’t do that. They do it for a quick demo video with speakers they are borrowing to review, essentially. If you play a 25hz test tone you can do the same, and you can also cook your drivers if you want.

My J2 dac doesn’t have a screen and it stays on inside a cabinet. Amp and preamp are powered on and off as needed.

Not clipping under normal circumstances, as others have said you are likely using less than 2 watts of power even at high volumes. I’d sent the amp in if it’s under warranty. After checking another amp to make sure it isn’t the speakers.

Your Yamaha claims “ToP-ART (Total Purity Audio Reproduction Technology) combines a symmetrical circuit layout along with anti-resonance construction for high-quality sound with minimal distortion”. So you own snake oil, buy your own account. Thd isn’t the only thing that determines sound quality, sorry. But if you like your amp, enjoy it. Don’t claim it’s as good as every other amp in the world.

Damn, some of those krells went so cheap. Weird time in the world for mid-high end audio. Truly high end folks would never buy a used Krell, but those of us with ok budgets would have loved to be local. $20k plus retail going for under $3k is not normal. Hope the new owners enjoy them!

Season to taste. I’m with ya.

You want downward slope. The original curve is very bright, and likely fatiguing. I’d leave the bass alone (or put a peak filter at the big hump) and then keep the top end filter. See how that sounds.

AB or A amps are similar in performance to what they were 20 years ago, but preamps have come a long way lately IMO.

Depends on what you want. Some have a big soundstage but it won’t be razor etched pinpoint. Some have a pinpoint soundstage but it’ll be moderately sized.

Older klipsch (I.e LaScala or Cornwalls or even fortes) will have a nice balance of big but detailed. They add to it by sounding properly live and surprisingly smooth.

Any modern meta kef will be very precise but nowhere near as vast or live as big horns.

Personally, I’ve owned ls50 metas and some great single driver setups and classic 2 way designs. Then I heard old klipsch with 15” drivers and never looked back. Now I have forte IIs, kp301s (bigger chorus essentially) and LaScalas. No they’re not going to measure flat, but man they are special and do things no other speakers do.

Go listen, it’s all you can do really. Hope that provides a little insight, everyone has their own “ideal” in this hobby.