Let's talk cartrige loading.


Some if not all of us vinyl listeners have run into this issue at some time during our quest for improvement of sound. Not many, myself included, are thoroughly educated in the subject matter. For instance my phono stage allows for a variety of loading options, 20, 75, 100, 230, 300, 1000 and the mm standard 47k. 
If I wanted to change to a mc cartridge would I be limited to cartridges which call for one of these recommended loading options or can a cartridge with a higher or lower loading be used? If a higher or lower were to be used what would be the positives or negatives by using say for example a 400 load recommended cart or a 200 recommended cart? Where and what would the sonic detriment be? Just what exactly does loading do. Is a low loaded cartridge inherently better than a high loaded? Should you get as close as possible to a load your phono stage is designed for? Why?
So much confusion, so little time.
Please all you in the know, let's hear your input and give us mc novices some of your experiences and insights.
I'm not new to vinyl myself but was limiting myself to mm carts because they are a standard load therefore I can safely try any make or model. I myself would like to try some mc carts but need to be much more educated on their functions and traits before spending that kind of cash.

128x128gillatgh
MC loading is a very subjective topic -- for everyone who insists that there’s a black/white difference between one load and another there are just as many who say it makes little if any difference. In large part this is because what loading does is actually change how the downstream pre-amp deals with RFI produced by the interaction between the cartridge and the cables it is connected to

Tom (of Galibier Design) has an excellent discussion of the topic here and his advice is spot on -- as you can see even when a manufacturer insists on a given load this result is itself a function of the phono stage and downstream preamp in use so may not be true in your setup. You have to try a range and see what works for you, and unless you have a really wacky and unstable amplifier you should have no risk of every causing any problems.

This page from Hagerman (http://www.hagtech.com/loading.html) also gives you the maths and illustrative charts of the impact of loading on frequency response -- but again what works in your system, and for your hearing, is going to be different then what works in mine

I agree with Folkfreak completely. I take what is recommended as a suggestion and start there. It doesn't always stay at that point. Case in point; the cartridge I have now is recommended to be set at 100. I run it at 800 because that is what sounds best in my system currently. 
Although I agree with much that has been stated, I strongly disagree with anyone who says it makes little to no difference. For those that think this, I have one suggestion, try a Qtip!
Perhaps Atma-sphere will chime in here. I think his basic message is that the optimum resistive load in the phono stage is essentially a reflection of the stability of the phono stage itself.  If your phono stage can tolerate it, you're actually best off using the 47K ohm load.  After several years of resisting this advice because of the generally accepted dogma to the contrary, I finally tried 47K, and now I find I prefer it with all of my LOMC cartridges.  My personal experience is that I can lower the load resistor all the way down to about 1000R with most of these cartridges, and there is not too much difference between that lower value and 47K.  Below 1000R, the sound seems more closed in and as if the highs are very slightly rolled off or "darker".

I think Jonathan Carr of Lyra, also espouses this rule of thumb.