Emo dumps Carver, the Carver site is down.

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I sure hope Emotiva bought the designs for his 900 watt 4/chassis monoblocks. Bob made a few sets of 21st century updated version of the award-winning Silver Nine tube amps. They were on the drawing board to be released by his company.
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I wonder who will handle existing 7 yr-warranty on my VTA180 -
Bobcarver.com is no longer existed

Maybe here? http://www.carveraudiorepair.com/

This site is 3rd party who handle Sunfire Corp. solid state products.
I don't think it handle Carver Tube Amp - and who will pay for the repair bill?

- and who will pay for the repair bill?

Unless Emotiva markets the specific line, I would not necessarily expect them to handle warranty issues. This seems to be a little different relationship than say, when Conrad Johnson purchased McCormack because they immediately continued to carry and sell the line, and they took over warranty service, I believe. You should contact them and ask.
Aren't tubed amps relatively easy to diagnose and fix, unless you fry something irreplacable like the transformers Bob wound special? There are several noted repair folks around the country who should be able to help if you ever need it.