MM Phono Input impedance change 47k to 100k ohms

" 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!

I agree with Al. I have sold, (I was a Grace dealer) and personally owned many various F9 cartridges and have found that in most cases, the 47K setting is perfect. I currently have several F9E's and have tried many different phono stages with them.

I have owned a couple different phono stages that allowed the 100k setting, but I always went back to 47K. IMHO, the 47K setting is just fine.

If you are an ex Grace dealer then you should read Grace Catalog with recommended loading for F9 series where you can read than MANUFACTURER RECOMMENDATIONS is 100k Ohm, especially for those models with extended frequency range up to 60kHz. This is where 100k Ohm is mandatory. There are a few models in F9 range than have Shibata type and LineContact type of the stylus, those models are "F" and "U". Same situation with advanced series of the cartridges that curpassed F9 series in everything (those are F14 and LEVEL II series from the 80's with exotic cantilevers and advanced styli like MicroRidge). 

Every Grace owner MUST try 100k Ohm recommended by the manufacturer, but the acceptable range is 47k - 100k. 

 

 

@chakster...I just pulled out my dealer binder from Grace.  The literature for the F9E & F9E Ruby, state 47,000 as the recommend load.

The brochure that has the F9F/F9E/F9L/F9D/F9P all state a load of 30K-100K.

As I stated, I tried 100K a couple of times.  Liked it better at 47K.

My first experience with a 100K load was with a Grado TLZ.  Word was around that it really liked 100K.  Sure enough, it sounded far better at 100K than at 47K.  Since the TLZ was/is not even an MM but is an MI type, I never did assume that 100K would be better for (all) MM cartridges.  Some will sound better at that load value; some won't.  But I never found 100K to sound "bad", either.  In the separate MM only stage that I use in one of my systems, the load R is 100K.  In my other system I use a Manley Steelhead with its fixed load of 47K for MM.  I did buy resistors to convert it to 100K but have not found the compulsion to make the change.  I've got enough other bits of audio repairing to do before I do that.