First Test for tube bias on ARC Ref 110?

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.

I have to agree that auto bias is a very convenient feature, but I think it slightly hampers overall transparency. I have also owned the Primaluna Prologue Two and then upgraded to the Dialogue Two (both with KT-88's) and both are lovely amplifiers for the money involved, but after comparing to others in relatively similiar price ranges (Rogue, ARC's integrated) I could definitely hear a more transparent sound in those without auto bias. These differences could potentially be many other things, but on first glance, that is my assumption as to what differs between them electronically. This is not meant to put down Primaluna in the least, again, they are great amps, though I think you pay a small price for the ease of use with auto bias.

70 total hours of running in so far, I just checked tube bias for the first time on my Ref 110 and three of the four sets were running just a little bit low. Should be at .65mv according to ARC manual and they were running around .61-63mv. I assume this is a very minor/mild drift. I adjusted the three sets that were slightly low back up to .65mv and away we go... I will check again at 100 hours. This was my first time biasing an amp, and I found it to be kinda fun!

Cmalak,
Why do you thing that it's done by "added microprocessors and digital circuitry"?
1. Autobiasing is done in DC domain and does not affect the signal no matter what kind of components are being used vacuum, solid-state or ICs.
2. Autobiasing could also be done without using any "added microprocessors and digital circuitry" by common cathode resistor(1940's?), but modern means of autobias widely implemented in Quicksilver amplifiers not only save tube life, but apperently improve sound! Stable quiescent grid current is a "dream:" of every tube push-pull amp.
Pardon, but I don't see this as convenience only feature.

Marakanetz...I guess we will just agree to disagree.