Attention K&K phono pre owners:

I just installed the new plate-load CCS mod and new input FET last night. Initial impressions are extremely favorable. I'll need at least a couple of days to let everything settle and break in after which I'll post more detailed sonic impressions.

Well, I have finally upgraded my 3 stage differential phono pre with only a couple of hiccups. Blowing fuses on turn on that seems to be the result of a weird problem with the power switch and a lack of signal in the left channel. In my hast to finish I neglected to solder one of the connections from the board to the interstage transformer. My bad. In my defense, this upgrade was a little more involved than that of the SE version. Four plate loads, four FETs, replacing 10 MOSFETs in the B+ and cathode "tail" current sources, building a new higher voltage negative choke input supply and a PS mod. As to that PS mod, if you want to make a nice upgrade to your phono pre it will not cost you any money, only some of your time. It involves rewiring the PS choke as a "common mode" choke. You can refer to the Lundahl data sheet for the connections.
http://www.lundahl.se/pdfs/datash/1638.pdf
I was so impressed with the improvement that I have rewired the chokes in my line stage and my mono-blocks to good effect.

The audiogon editor seems to have truncated the web listing. You can view it at the K&K forum under data sheets and LL1638.

Can the Maxxed Out K&K phono be configured for true balanced INPUT, using XLRs instead of RCA jacks? (I know that it can be built for balanced OUTPUT.) Thanks.

It has "true" balanced inputs through its RCA jacks. Just use the switch to lift the ground connection. That's one of the virtues of transformer coupling. You can always have balanced connections.