Load capacitance

[denti alligator]

Different phono cartridges specify ideal system load capacitance in pf. What is this and how do I know what my system has?

[Doc B.]

You combine the capacitance of your phono cable (usually quoted in pF per foot or meter) and the input capacitance of the phono preamp. For an Eros it's about 15pF IIRC.

[Grainger49]

You need to find the capacitance of the cable between your table and the Seduction.  PJ has posted the Seduction input capacitance somewhere.  You just subtract the Seduction capacitance and the cable capacitance from the optimal load and then buy some caps to parallel with the 47k ohm input resistor in the Seduction.

Doc posted while I was typing.

[Laudanum]

For Seduction, it's 60pF, IIRC.   Add that to the tonearm wiring and you have your total number.   You can measure the wire/cable capacitance if you have a meter capable of measuring low capacitance accurately.  A lot of meters dont but they do make meters just for measuring LCR or even specifically for measuring capacitance.    You can do a search on the net and probably find the capacitance of the stock Rega arm wiring.  Ive seen it before.  I doubt that it's higher than 150pf and maybe closer to 100pF.   I wouldnt get too obsessive about it though.   As Grainger suggests, you can add capacitance but you are probably in the ballpark as is for most of the modern MM carts.  For example, the popular Ortofon 2M series all "want"  150-300pF. 

[denti alligator]

Resurrecting is thread because I read on some forum that my cartridge, the AT 150MLX sounds much better with a higher capacitance.

See http://www.vinylengine.com/turntable_forum/viewtopic.php?f=19&t=51629

How would I go about upping the capacitance in my Seduction?

[2wo]

How about trying different or longer interconnects from the TT...John

[Paul Birkeland]

read on some forum that my cartridge, the AT 150MLX sounds much better with a higher capacitance.

See http://www.vinylengine.com/turntable_forum/viewtopic.php?f=19&t=51629

How would I go about upping the capacitance in my Seduction?

You can add capacitance across the 47K resistors across the input jacks, though this thread refers to actually changing the 47K resistor to a lower value all together.