Question: What year were outputs is 2x Pro Bias, RCA Loop Out and notes is Vacuum tube released?
SQL: SELECT "Release Year" FROM "1-25276250-3" WHERE "Outputs" = '2x Pro Bias, RCA Loop Out' AND "Notes" = 'Vacuum tube';

Question: How many outputs are there for Solid state, battery operated for portable use listed in notes?
SQL: SELECT COUNT("Outputs") FROM "1-25276250-3" WHERE "Notes" = 'Solid state, battery operated for portable use';