a lowly 6.1. Lowly in that some regard it as less, as it came out right when Paul was not with them for a bit. But, it came directly from the 6.0 which was his, and was simply an extension of that model and has both a bypass and straightwire mode that can make the unit completely passive other than a volume control and source control. I think it sounds really good. (and as it directly descends from a Paul design with an improvement that continued on, I reject any snootiness about it that I read). I got it very inexpensively, I think, buying it and my Hafler P-225 together from a member in Bend, OR. I have been pleased.