Success!   Replacing the two capacitors C05 and C06 fully restored the function of our soundbar!   5 Volts is once again 5 Volts.   Thank you all for posting on this forum and especially to those who diagnosed and shared the solution(s).   I bought two of these Panasonic caps from Mouser for 38 cents each.  Shipping was about 10X that!   EEU-FR1C221B Panasonic | Mouser   So less than $10 to avoid hundreds in replacement cost!  Hopefully it lasts another 4 or 5 years.   Interesting to me that the 5V side of the supply stays powered continuously by design.  This means the capacitors in the 5V side have higher risk for wear-out than those on the 20V side. The Panasonic caps I bought were rated 5000 hrs at 105C.  I'm confident the temperature was lower, but for something continuously operating, 5000 hrs isn't much, even if the temperature was a lot lower.   Speaking of reliability and temperature, what is that white glop?  Is it to conduct heat or prevent mechanical vibration?  It's a pain to remove!   Variation in the way the white goop was applied probably has an effect on the operating temperature of these capacitors.  This may be another factor in the variation of time to failure (although the variation in part to part will probably be huge, along with the variation in customer usage and power-on hours that could heat these caps).

Yes not a super paint job with overspray yet, maybe. At least took the hardware off before...glws!

That's a nice write and if I was going to drop $40k on a pair of speakers, this is how I'd go about it.  Congratulations on your new stereo purchase, hopes it feels your needs.

Stranger things have. happened, yet when and what, where?

The new La Scala will ship with a traditional passive crossover network like the current version.  An available option will be an active DSP crossover.  This will split the signals for the tweeter, squawker (midrange), and woofer at line level, before amplification.  Therefore, you will need three channels of amplification (triamp) for each speaker.  This configuration sounds far superior to the using the passive crossovers.

Yes.  If you damaged the woofer you should be able to purchase a new one.

Are you adjusting the volume on the source or on The Three?

Thinking go with @G Cheung advise... Excuse @geoff. Advise!

Hi @AnalogPete, this seems like deja vu, but I recently built a couple different ALK designs to hear for myself in my La Scalas, apples to apples.   To date I’ve built the ALK A, ALK A/4500, ALK for Klipschorn, and most recently the CSW-450.   I guarantee you will NOT like the CSW-450 in your Khorns. With the stock 33uF cap it crosses at 600(-ish) from the squawker. It also drives the woofer higher before it crosses, which Khorns won’t reproduce. I have since cannibalized those boards after jumpering parallel capacitor values to simulate both the mid and woofer filter values of other ALK and Klipsch designs.   The ALK for Klipschorn is the gear to my ear. It has the second order woofer filter you (and I) seek. The stock CSW-450 would be great in a Cornscala.   John Warren also has a design similar to the ALK for Klipschorn that I built as well. His design really centers on the flexibility of the squawker filter and allows you to pick whichever woofer and tweeter filter you prefer. Ironically I found the simple first order 2.5mH woofer filter to sound the best (?).    *** If you opt for an ALK design there has been a recent “improved” revision to the coil value in the tweeter circuit, Al has penned a value of .15mH vs the original .20mH.       

Thank you!  I think you are suggesting emissions testing happens at a product level so the mitigation might be different even though the power supply is the same.  Must be a predictable radiation risk to plan for that when the board was layed out.  Cool!