I finished my first build, a C84, and installed it in my new CH02 chassis a couple of days ago. I couldn't be happier with the results.
I had no prior experience soldering on a printed circuit board, but I did my research and bought some of the tools that Tim recommends, so I felt prepared.
Overall, the build was painless. I measured resistors as I went, paid close attention to transistor markings and polarized parts, and had ZERO problems during power up and calibration.
The toughest part of the build was the surface-mount transistors, but with patience and attention to detail, I was able to complete this step with very neat-looking results.
I have been able to compare my preamp to a friend's Millennia. The C84 I built has a flatter frequency response and a significantly lower noise floor than the unit I compared it to. It sounds great too, btw.
(Your results may vary, of course!)
I calibrated for +/-18 V according to the instructions; I am still thinking about going back and increasing the supply voltage. According to the datasheet, it seems that higher supply voltages give you (aside from increased headroom) greater slew-rate, but lower open-loop gain and less power supply rejection. Maybe +/-18 is the optimal tradeoff between these parameters. Could you comment on this Tim? Maybe there are other factors in your circuit that would make the graphs in the datasheet inapplicable here.
Again, many thanks to Tim for the well-designed kits, the clear instructions, and the sense of satisfaction of hearing a stellar preamp that I assembled myself!