sreten wrote:Ortofon used to supply stereo 200pF capacitors that slid between their cartridges pins because some users did not have enough capacitance.
Around 400pF used to be needed to give an overall flat response.
Too low and lower treble dipped and the top end became peaky.
In some cases it is viable, or let's say desirable.
But those are the rare cases when the response of the cartridge/stylus combination is not neutral, it has an intrinsic dip in response on the audio band.
Capacitance can be used to compensate that.
Let me give you a cheaper example.
I have an AT110E, which I don't use.
Unfortunately I cant't find any references to the inductance of this cartridge, along with other important parameters.
Resistance is easy to measure, though.
Anyway, listening to it and adjusting the loading by ear, the sound is always smooth, sleep inducing. It has good dynamics, though.
No top end to talk about, and even the midband is recessed.
At 75K input impedance on the pre, the treble gained new life.
But the midband maintained that recessed nature.
I know I could easily compensate for this at a flip of a switch (in my case), bringing in the 100pF cap on my phono pre (for a total of ~200pF capacitance).
That would probably bring a new life to the midband and lower treble, but then the high frequencies would be rolled off sooner.
Truth is, with that cheap stylus there's no miracles, and not much one can do to put it singin' properly.
Btw about that Ortofon, I think it is rare that one would need those 200pF caps. And they also add weight to the cartridge.
Most commercial MM preamps have a 220pF cap (and some even more) inside, across the RCA inputs, as a "standard" value, along with 47K impedance.
It is easy to get to the recommended (by Ortofon) 400pF capacitance, if you count with cable capacitance, specially if it's a 1 meter cable.