http://www.6moons.com/audioreviews/stepup/primer.html

http://www.kandkaudio.com/mccartsetup.html

It is my understanding that the capacitor settings will mostly affect the high freqs. I would spend time with each setting and see which one you prefer.

If I reall Shures and some others required a higher capacitance load than most to not sound strident and bright. Your ears will guide you.

As with loading I would try and start at the lowest R value, listen and see what you hear, especially in the low freq range and work you way back up to 47K.

It's your sound system so your preference is the winner.

Since the dawn of high output MC cartridge time, High output MC's have had a reputation for being slightly foggy and having accentuated highs. Not good. However, this has improved as issues go. If one has a very good phono stage, then low output MC is always the way to go. Low inductance, low mass, and low ringing.

One way to get a high output MC to perform is to start at 47k loading and move your way down the resistance steps. Try 20k ohms to start, then try 35kohms. See what you think of the two settings. Try going even lower to see what it does. Sooner or later you will reach a balance that works for what you think should be coming out of the grooves. One way to check on your progress is to first ascertain that the tracking and positioning of the cartridge in the groove is correct, with regard to mistracking. Then move on to playing with the resistance. One can also use a CD copy of the same LP's being used to check tonality balance for neutrality as the tonal balance will change with the changes in loading. What you are doing is you are attempting to reduce the inherent ringing in the high output MC via dropping the loading.

In a low output MC, the loading can be as sensitive as 10 ohms difference to get it right. high output MC's will not be as sensitive as that, but will find themselves getting to about 500 ohms being differences on either side of the correct loading being noticeable. We are talking about a motor driving a load, ie the cartridge driving the loading and preamp circuit, so the loading can affect tracking, which is why it is critical to get it (the tracking) right before you start messing with the loading, as the two will cross affect one another to a minor degree. Due to the loading affecting the tracking (this is most noticeable on low output MC's) thus the two things working doubling the 'effect' of loading (electrical and mechanical), MC carts can be quite sensitive to loading changes. This makes finding the correct figure that much easier, rather than being more difficult. Just be sure to get the tracking as perfect as possible before messing with the loading so to as avoid compounding your possibilities of issues which will compound your confusion. As you go from too high a resistance figure to too low, the cart will 'seem' like it is too bright (and possibly mistracking) to sounding dark (as you go to too low) and dynamically 'slow'.

One other thing is that none of this should be tried until the cart is broken in and and is correctly positioned in the groove. Once a person has done this a few times, they can then do all of it at the same time and be capable of separating the concurrent issues. At least some of us can.

MM and MC carts are are basically damped springs connected to a magnet that wags around (like a dog's tail) in a coil (MM) or to a coil that wags around inside a magnet (MC).

The damped springs are apt to resonate (oscillate) when excited (by the grooves in a disc). The frequency they oscillate at depends on their construction and the amplitude depends on how well they are damped.

MM and MC carts are also inductors and together with the cable and phone pre input capacitance they can resonate (oscillate) electrically when excited by an electrical voltage. The frequency they do this at depends on the inductance and capacitance values and the amplitude depends on the resistive damping (input resistor setting).

So after all that, these carts have two possible resonances - one mechanical at probably a lowish frequency (up to say a few KHz) and an electrical one probably right near the top of the audio spectrum (10KHz to maybe 30 or 40KHz).

The effect of these resonances is to make transients 'ring' (the way a single 'tap' makes a bell ring at its resonant frequency). This will tend to slur and muddy the transients and make them sound slack.

Changing the resistor settings changes the damping of both the mechanical and electrical resonances so as you lower the resistance you should hear transients 'tighten up' and as you raise the resistance you should hear more 'ringing' on transients or 'slackness'.

Changing the capacitor ONLY changes the (higher) electrical resonant frequency - it does nothing to the mechanical resonance. So as you increase the capacitance the electrical resonance falls. This resonance sounds like a presence peak as if you used mid boost on a mixer but the boost frequency can be very high - over 10KHz - so it often adds 'air' to the sound and can compensate for a loss in top end in many cartridges. The overall effect should be a 'brightening' of the sound.