MM Phono Input impedance change 47k to 100k ohms

I fully agree with everyone else; there is nothing "wrong" with using a 47K load with the Grace or any other MM cartridge. (And, as I think I wrote above, I was not aware that Grace recommended a 100K load, if that is the case.) It's just a matter of taste and tonal balance. Ironically, many/most of the best vintage preamplifiers (which in those days ALWAYS included a first-rate MM-capable phono section) included front panel controls for adjusting cartridge load in terms of capacitance and resistance. I have long contemplated buying one of those old-timers for this purpose, but then I would find myself trying to upgrade the sonics. But we've been over this ground before. Candidates I've considered include the one from Yamaha, one of the old Krell preamps (KPA, I think), Accuphase C200 (I think), possibly the HK tube preamps, etc. Unfortunately, others recognize the virtues of these TOTL units and they ain't cheap.

Calbrs03, I share your love of the Grace Ruby. It would interest me to know something about the rest of your system, to learn whether there is some particular synergy we are both tapping into. My system is posted here. Suffice to say I use huge ESL speakers driven by OTL tube amplifiers. The Grace is mounted on a Dynavector DV505 feeding a (tube) Silvaweld SWH550, which I use exclusively for its MM phono section. The Silvaweld feeds the high level section of my Atma-phere MP1 preamp. Unable to keep my hands off anything I own, I am in the midst of some major upgrades to the Silvaweld, even though I liked it as it was when purchased. It will be a whole lot better when I finish my work.

Lewm: that's a very impressive system. If anything, I think we share the same interest in modifications. Tinkering, my wife calls it--something I picked up from my dad who was an EE and fearless when it came to taking complex things apart and putting them back together.

I have Cary SLM-100 monoblocks that I gutted and rebuilt; a Cary SLP98P which I also modified; my maxed-out Bottlehead for MM cartridges; and an ASR Mini Basis that I have yet to touch for MC cartridges. The speakers for now are ProAc Response D28s, Silverline SR17s and Altec Valencias that I've rebuilt and willed into shape from the ground up. I go back and forth, changing one set for another as I feel.

The source is a rebuilt (not by me) Garrard 401 in a Woodsong plinth with a Schick arm. I use this with a Denon 103R. I used the Graces with a Graham 1.5t on a variety of other tables, but that arm won't work on the 401's plinth, and I believe the Schick is too heavy for the Grace suspensions. For now they'll have to sit in their boxes while I look for another 12 inch arm to use specifically with the Ruby and its brother.

Making sense of loading confusion, I think is helped (Ralph or Lewm, feel free to chime in/correct me) by understanding that the resistor is going from signal to ground. The higher the resistor value, the less "shorting" of the circuit there is. So higher resistance values mean less loading though it is easy-if you don't understand circuits (I raise my hand) to assume that higher resistance means higher loading. 

" higher resistance values mean less loading".  According to current parlance, this is correct.  There is nothing self-evident about it, but that statement does conform to the definition of a "load", where one component has to drive another.  The closer the input impedance of the downstream component gets to the value of the output impedance of the driving device, the more work, in terms of current, the latter has to do to drive it.  Hence, the downstream device is a "load".  Anyway, that is the way I think of it in order to keep the definition in mind.  I wish Almarg was around these days.

I wish Almarg was around these days

+1...Miss that guy!