Well it's been a while since you posted and you probably have your preamp ....go with the 5k if you plan to ues a low output cartridge, under 1mv. This is what it was built for. The 5k uses video buffers to improve specs...at that time overseas sales was important so specs ruled. In Mikes upgrades he removes the buffers. I beleive there is a buffer defeat but does it really? There is also a ton of switches that the 5.1 doesn't have. Mike removes them too in his upgrades. The 5k also uses 2-6922's in the power supply...this is not what they were designed to do but it does work. Now the 5.1 will only work well with higher output cartridges. I'm using a Benz H2O...2mv or so. Volume usually set between 9 to 12 not more. Low output cartridges don't work here. There is too much tube noise, and I'm using red Amperex 7308 LOW NOISE TUBES! The 5.1 uses a pure tube path without everything that the 5k puts in the way for specs but it does low output extremely well. As for the 5.1 power supply, it is of a purer tube path again. Just take a look at the tube selection. Compare. Take a look also at the tube selection in the SA9. See a resemblance. Mike now offers a upgrade called the SA9 jr. Guess what, it's from a 5.1. The 5k is nice and big and a new type of look...the 5.1 thin, older but alot cheaper! I've had both in my all Counterpoint system...they are very close IMHO. Depends now on the cartridge you want to use and your ego. Hope this helps Kurt. Harvey B.
