[doak]

So just to be clear, if someone received an L4 with 6x5 rectifier listed on the back it will have two of these tubes inside?

My DAC is a G5 L4 and uses a single 6X5 for rectification.

BTW: I am liking the Bendix 5852 a lot. No A/B yet, but will come.  Want to get it well settled in & not in a hurry to pull it. 

[sfox7076]

I am not sure actually.  This is a Level 4 with the 6X5 and there is only one...  http://www.enjoythemusic.com/magazine/equipment/1214/LampizatOr_Generation_5_Level_4_DAC_Review.htm 

Maybe only the Level 7 (predecessor to the Big 7) needed 2.  Sorry for the confusion.  As to how well a 6 volt rectifier runs on 5 volts (it will clearly run, at a higher current draw), I cannot say.  Seems like you may starve it a bit.  And a 5 volt in where a 6 volt would go will push the filament higher than I would want it to be.