I run my A200's with a 50wpc Arcam Alpha 8, solid state which easily drives them in my fairly large 29' -15' room.
So 25wpc tube should work well.
Also consider upgrading your A200 feet and add spike's if they are on carpet. About 20.00 ttl parts and 1 hour of labor. Nice improvment..
Parts express sells spike kits, 6.00 per speaker. 5.00 worth of oak wood @ Home Depot. 2" wide 1/2 thick. Paint black or leave natural depending on speaker color.
So 25wpc tube should work well.
Also consider upgrading your A200 feet and add spike's if they are on carpet. About 20.00 ttl parts and 1 hour of labor. Nice improvment..
Parts express sells spike kits, 6.00 per speaker. 5.00 worth of oak wood @ Home Depot. 2" wide 1/2 thick. Paint black or leave natural depending on speaker color.