A properly implemented auto-bias system implies digital components, microprocessors, ADCs and DACs. In order to be reliable and not affect sound quality it will increase the price of the amplifier significantly. Also long term serviceability can be an issue, needing trips to the factory.
As I always use tubes pre-conditioned for 50 hours I check bias after the first 100 hours and then every 500 hours.
As I always use tubes pre-conditioned for 50 hours I check bias after the first 100 hours and then every 500 hours.