@sbank
If I understand, this suggests that with MM carts you will want to experiment with going from 47k down to 2k or somewhere along that range. The GIANT thread here on MM implies that consensus view on changing away from 47k is in the other direction up to 100k or even more.
Right, for MM cartridges the 100k is universal and in most cases much better than standard 47k. All my MM cartridges sounds better at 100k.
As for the MC and MM/MI:
In conversation with Joe Rasmussen of the JLTi i've learned this:
"Do not be afraid to do the
opposite, for example, find the resistance
of the cartridge's coil, it is usually in the specs. Now multiply that with about
1.6x and find the resistor value near that. Rather than unloading by going high,
this in fact causes the coil to produce more current and hence this introduces
electromechanical damping - the output will be lower, so keep that in mind, and
explore the final value, deciding by listening. For example, my Benz MC is 38 Ohm (38R) and I am using 68R
load resistors. Yet a friend used nominal 47K and never tried my recommendation,
so don't be afraid to try 'electromechanical damping' as it too can be tuned and
you may like it also, even possibly better.
A friend with a Grado Platinum MI cartridge ended up using 2K2
resistors (2K1 when in parallel with 47K). I think the DC resistance is 600R. He
said it was like getting a more expensive cartridge. With an Ortofon Jubilee with 6R coil, we gradually went lower and lower until
10R and the owner went Wow!"
P.S. It was a pleassure to deal with Joe Rassmussen, i ended up with a bunch of resistors he gave me (and RCAs) to experiment with different cartridges and a custom JLTi phono stage which is reasonably priced! I'm sure Joe can answer all the questions by email.