The set of amplifiers was made in 1990 by Phase company in Ukraine. There are only two such sets in the world. Unfortunately, these amplifiers were never used and stored all the time in the closet. I checked them, they work fine. Unfortunately, I do not have more information.The set includes only:1. Two- 63- (6P3S-E equivalent to 6L6GC). The item "Tube Amplifier set (New. Very rare)" is in sale since Friday, January 31, 2020. This item is in the category "Consumer Electronics\Vintage Electronics\Vintage Audio & Video\Vintage Amplifiers & Tube Amps". The seller is "hiendaudio*1" and is located in Redondo Beach, California. This item can be shipped worldwide.