Capacitance loading and fixed coil cartridges


Hi all.  I am looking at all the various models of Soundsmith cartridges and seeing three different output levels, 2.12 mV, 1.1 mV and 0.4mV). I happen to have a low output version. I was wondering if anyone knew if the ideal amount of capacitance applied by the phono preamp (and phono cable) was dependent on the cartridge output?  In other words, higher output MM and MI cartridges require more capacitance and lower output cartridges less capacitance. Is this on track? How does inductance play a role here?  

-Karl
128x128karl_desch

Showing 6 responses by karl_desch

Thanks sfall, my question is not about how to deal with low output from a gain perspective but rather if low output fixed coil cartridges need a little capacitance unlike low output MC.  I use a phono pre that has no problem with gain or resistive loading (Pass XP-15) but not sure what to set for capacitance.  Here is the relevant section from the cartridge manual which doesn't really answer the question, but of course I understand that it all comes down to listening preferences.

"The new Zephyr MIMC Star requires a MINIMUM RESISTIVE LOAD of 470 Ohms, with best loading determined by your system and your listening preferences. Usually, this is between 470 and 1000 Ohms. There is no harm in using a 47K typical MM load, but you may experience a peaked high end. Capacitive loading may reduce that effect somewhat to a satisfactory degree. Again, loading requirements will be determined by your system, and your personal listening preferences. PLEASE NOTE that loading well below 470 Ohms will result in loss of high frequencies."

Does this mean at proper resistive loading, I don't need to add capacitance? Just trying to learn more about cartridge electronics, otherwise I would just email Soundsmith.

-Karl
Thanks doncito101. I'm not asking if capacitance on the phono pre/cable affects output of the cartridge, but rather, if low output MI cartridges, like the SoundSmith Zephyr Star, benefit from capacitance loading like some higher output MI/MM cartridges? This is assuming the cartridge is getting the right amount of resistive loading and is on a compatible tonearm. 
The dealer recommended capacitance loading around 400pf total FWIW.
Thanks lewm and Ralph.  Your posts are very helpful.  I particularly enjoy the units of inductance as milli Henries.

I have a low capacitance phonocable and have the preamp set at the lowest capacitance, 100pF.  I am resistive loading the cartridge with 1000 Ohms.  Currently have about ten hours on this guy and it is sounding sublime.  
-Karl
BTW,  I have Ralph to thank for suggesting that in my system, that is a true balanced circuit from phono pre to power amp, that the interconnect is probably not a factor in its sound quality.  I spent a whopping 60 dollars on a pair of 20 foot Canare star quad cables and moved my entire rig away from my speakers and power amp.  It has never sounded better.