Mike,
Your Yamaha MX1/CX1 was produced between 1994-1998 and was the replacement for the M85 series 1986-1988 and the MX1000u/CX1000u series 1989-1992.The earlier amps had 260 watts per channel and red led meters compared to your MX1 which was 200 watts per channel with a plain face.
Your MX1 weighed in at 52.9 pounds and the CX1 at 19.4 pounds.All this equiptment was Yamaha top of the line back when they came out and was truely the last of the true Yamaha hi-fi-especially when compared to the equiptment made after this time.
The 10.000 series (MX10000/CX10000)was Yamaha 100th anniversary models and was truely in a league of their own.Titanium finish with genuine walnut endcaps,Pure Class A,just a great amp.The only problem was their cost,thousands above the other amps mentioned so very few were sold.
Hope this has helped.
Jeff