I have the Luxman as55. Found it on eBay from a guy about of Japan. It is built like a tank and works perfectly for switching between my 2 amps to a single set of speakers, It works both ways. I believe they have been discontinued. But are not hard to find. Original price was like $1000.00 I paid $360.00 for mine in perfect condition. I would highly recommend, I can’t imagine there is a more well made unit available.