user: Question: What year were outputs is 2x Pro Bias, RCA Loop Out and notes is Vacuum tube released?
Columns: ['Driver Unit Model No.', 'Release Year', 'Output Voltage (RMS)', 'Inputs', 'Outputs', 'Notes']
Types: ['text', 'real', 'text', 'text', 'text', 'text']
Sample row: ['SRM-001', 1995.0, '240V', '1x Miniplug', '1x Pro Bias, Special 6 Pin', 'Solid state, battery operated for portable use']
SQL:

assistant: SELECT "Release Year" FROM "Table" WHERE "Outputs" = '2x Pro Bias, RCA Loop Out' AND "Notes" = 'Vacuum tube';