Audio Research I/50 Integrated Amp

I really enjoy my I/50, but I just replaced the left channel 6922EH driver tube. It was probably original, and I bought the amp used (it was used as a demo unit by a reviewer who must have played it). No biasing needed, only the power (6550) tubes need biasing. It is a shame the amp has to be sent somewhere and can’t be modded for user servicability or auto-biasing. I have also a Willsenton R8, KT-88 push-pull integrated, with similar specs, and that unit is set up for user biasing which is not difficult.  I have to wonder whether they will continue the I/50 with a similar integrated offering what are considered improvements to the I/50. 

What is a lot, and where are they all?

I found 1 on USAM.

Many have been sold if you look under that tab. I saw a few on the Music Room website as well. 

The new I-70 is auto biasing. It just took time to get there. I remember when all tube amps had to be manually biased. Not that long ago. 

There are demos on-line how to manually bias the I-50. It is not hard... I suspect since the amp must be on and there are high voltages they were concerned with the liability of having folks do it themselves. There are some really stupid people out there. 

I’d swear there was a similar thread about ARC for sale everywhere not all that long ago.