Cartridge Loading- Low output M/C

Atmasphere 5-21-2018
This is because the cartridge inductance combined with the tone arm cable capacitance forms a tuned RF circuit- which is energized by the cartridge signal.  It can be over 30 db higher than the phono signal- thats about 1000x more powerful!

To add to Ralph’s (Atmasphere’s) response, with which I of course agree, the input capacitance of the phono stage will add to the capacitance of the phono cable.  And I see that the Koru provides two selections for input capacitance, namely 100 pf and 570 pf. You are likely to find that the 100 pf setting will allow you to use lighter loading (i.e., higher resistance values) than the 570 pf setting.

Also, related to all of this the following excerpt from a post dated 8-14-2010 in this thread, by Lyra cartridge designer Jonathan Carr, will be of interest:

I should now debunk another myth regarding loading, which is that low-impedance MC cartridges are insensitive to capacitive loading. OK, the MC cartridges themselves aren’t particularly sensitive to capacitance, but the inductance of the cartridge coils will resonate with the distributed capacitance of the coils and the capacitance of the tonearm cable to create a high-frequency spike, and this spike certainly is sensitive to capacitance. In general, the less the capacitance the better. Having more capacitance (across the plus and minus cartridge outputs) will increase the magnitude of the high-frequency spike and lower its frequency, neither of which is good news for phono stage stability or phase response.

Generally speaking, the greater the capacitance across the plus and minus cartridge outputs, the heavier the resistive loading needs to be to control the resulting high-frequency spike. Conversely, less capacitance allows the resistive load on the cartridge to be reduced, which will benefit dynamic range, resolution and transient impact.

Good luck.  Regards,
-- Al

The OP is asking for loading and not why many phono stages works in different way when we make load values.

Who cares, he as any one of us already owns a phono stage it does not matter what and no one can make a world research to find out which phono stages works as should be, it's imposible to do that.

So, what each one of us have to do is to load our cartridges according what we have and according each one music/sound priorities. That's all.

@krelldog You can safely ignore Raul's remarks in this matter. Most of the remarks above are false.

My prior comments were about the theory behind how all this works.
Regarding your situation, it is advisable to run the least amount of loading possible (by least, meaning the highest resistance with the least capacitance). To this end, you might see if you can find out what the capacitance is of your tone arm cable. If you can find a cable with less capacitance, it might sound better even though it might also be less expensive. A shorted cable will of course have less capacitance- for example cutting your cable to half of its length will double the resonant frequency (assuming no input capacitance in the phono section; some solid state phono sections have quite a lot of input capacitance due to the capacitance at the gate or base of the first semiconductor used). The more capacitance the cable has, the lower the resonant frequency and its best to keep the latter as high as possible.
If it just does not sound right with 47K as a load, I would use the highest loading resistance available to you that takes the edge off. I've not played with every Krell phono section but those I have have been unhappy without loading, suggesting an unstable phono section. The actual goal is not only tonal neutrality, but **also** the least ticks and pops. When you load at a very low value (like less than 100 ohms) its possible to reduce the cartridge output and also decrease high frequency tracking abilities. So this should be avoided if at all possible.
There is no 'set' value of loading that can be specified by any cartridge manufacturer (and suggestions from other audiophiles won't be ideal either). This is because they cannot predict the tone arm cable capacitance nor the input capacitance of the phono stage (ours tends to be quite low as this has been on our radar for decades). So the values you see cartridge manufacturers suggest are always generalities, as they can't assume that a given phono section is stable. But at the same time, this is also why 47K is suggested and is the industry standard- because its really all that is needed if the phono section is properly designed. 

Nicely said atmasphere!

@krelldog : Some persons think that invented the " black thread ". That atmasphere advice is the same on almost each loading thread from years but in reality does not solves what we are looking for. The theory behind that is true but through several cartridges I owned over time that capacitance issue never helps or damages the listening experiences through LOMC cartridges .

After you do what I posted you can make tests changing capacitance and you will attest what I said here.

@almarg , I read in the past that from J.Carr. Now, please tell me if you have first hand experiences where you can attest it.
In the other side in the Lyra website exist no single reference to that, here what you can read on the Atlas that's a 8-9+K dollars cartridge:

"" 

• Recommended load directly into MC phono input: 104ohm ~ 887ohm (determine by listening, or follow detailed guidelines in user manual) ""

there you can read what J.Carr yes the same J.carr you name it says: " determine by listening ".

@uberwaltz, " terrific "/great post from your part. Enriched the OP thread.


Regards and enjoy the MUSIC NOT DISTORTIONS,
R.


http://lyraanalog.com/atlas/

Raul.
Your pointless sarcasm does not go unheeded
Enjoy the music indeed......