An odd development.
The service manual clearly shows 10mV +/- 2mV for the idle current adjustment. Looking back I see that I didn't document what setting that I used my first unit but I did set it to 10mV.
With the 2nd unit I also initially set the idle current to 10mV. The odd thing is that after hooking the amp up with the Braun's and Denon CD player the volume control was
way to sensitive. It only took a
very small adjustment of the volume knob to go from quiet to
way too loud. Yes, I double checked that my meter was set to DC and not AC.
So I went back in and reset the idle current to 5mV as in the Yamaha A-520, just to see what would happen. This resulted in a far more normal volume tracking, similar to my first amp. This has me concerned naturally. I don't know if Yamaha made a running change without documenting it (like the changes that I found on the phono board), or if there is a problem in the amp. I'm going to have to open up my 1st amp and double check what I set the adjustment to, in spite of being certain that I set it to the stated 10mV.
At the moment the 2nd amp is working nicely at the 5mV setting but naturally I'm concerned that something is not right with this.
After repairing/restoring the speakers I actually tested them first on my 1st AX-500 and they needed a bit more volume knob adjustment than the Canton Quinto 510's need for a similar volume level (the Quinto's are what I'm using with the 1st amp), about what I'd expect considering that the Braun L-630's are larger. So it's not like the Braun's are so super sensitive that the amp is too much for them.
Cheers,
James