First Test for tube bias on ARC Ref 110?

It's the best phrase to cut corners, but reality is different.

I am not sure I follow your logic. Why is the exclusion of a self-biasing circuit cutting corners, if your primary goal is to produce superlative sound from your products and if you believe that the inclusion of a self-biasing circuit takes away from your goal of producing superlative sound. I am not sure I follow Marakanetz.

inclusion of self-biasing circuit only improves sound.

I check bias first day of every month on my ARC amp. Tubes from ARC, very little drifting.

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.

Marakanetz...I suggest you read what Microstrip has to say. I fully concur and any self-respecting tube amp designer will tell you the same. All the added microprocessors and digital circuitry will detract from the sonic quality. If you think Audio Research that has been in business for 30 years with too many awards and industry acclaim are cutting corners by excluding a sel-biasing circuit than I don't know what to tell you.