MM cartridges and capacitance

Al,
You are a scholar and a gentleman.
Thank you very much for that explanation.

Al, Thanks so much. This is the first clear explanation for the apparently paradoxical effect of added capacitance on the treble response that I have come across. Makes perfect sense, now. Your post above should be archived somewhere.

Perhaps a naive question:

If "higher than standard 47k" capacitance was known to optimize frequency response by an MM cart's designers, wouldn't they have included that higher capacitance value in the spec sheet for that cart?

I use MMs almost exclusively and find these discussions most informative, though I've no simple and reliable means to increase the capacitance loading via my MM phono stage.

T_bone & Lew, thanks very much for the nice words.

JB, in my experience MM cartridge specs do usually indicate recommended load capacitance.

The 47K number, btw, is not capacitance, it is the recommended load RESISTANCE (47,000 ohms) for many MM's, and approximately corresponds to the input resistance of many or most phono stages or preamp phono inputs, that are intended for use with MM's.

Recommended load capacitance for MM's is typically in the area of 100 to 400 pf (picofarads). The cabling will usually be a more significant contributor to that than the input capacitance of the phono stage or preamp phono input, if the phono stage or preamp does not have a provision to switch in additional capacitance.

As you may realize, capacitance can be added by soldering an appropriate capacitor to an rca plug, and connecting it at the phono stage or preamp phono input with a y-adapter. I have a commercially made kit that I purchased in the 1980's which provides a selection of rca plugs with capacitors of various values soldered onto them, but I haven't seen such a kit offered in recent times.

Best regards,
-- Al

DB systems apparently still makes the kit that they offered in the 80s, I just sold my old one. It was mentioned in Stereophile in the last year or so. I think it is $69.95, not a bad price considering it was $39.95 then. DB is a good company but one of the stealth variety, I had no idea that they were still going.