Cable capacitance

oldius

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Shown in product specs as <90 pf/m core to shield.

Am I correct in saying that a 3m run would give a capacitance of less than 270pf?

If so, would I load a cartridge that has a recommended capacitance of 400pf with 130pf?

Thanks, it's some time since I tried an MM cart and never since I had one and the facility to alter loading.

 

SergeAuckland

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Not quite. Don't forget that the phono stage itself will have some capacitance, so that has to be deducted from any additional loading. If this capacitance isn't quoted for your stage, I would assume it will be somewhere around 100pF, but quite possibly more or less, so I wouldn't add any additional loading initialy, but you could experiment adding small amounts, say in 50pF increments.

S

 

awkwardbydesign

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I'd actually not worry too much about the numbers - too many unknowables plus the effect of capacitance varies with frequency...In broad terms increased capacitance tends to roll-off bass and subjectively to spotlight higher frequencies. Therefore I'd do as suggested and start with none on your phono stage and dial it in or out by ear. :^
Back to front; as the capacitance is to ground it allows a low impedance path for HF, NOT LF.

The higher the capacitive value of the input of the phono stage, the duller the sound will be. The lower the capacitance of the phono input, the brighter the sound gets. A mismatch results either in dark dull sound or an overbright, distorted signal.

 
R

Reggie Mental

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Back to front; as the capacitance is to ground it allows a low impedance path for HF, NOT LF. The higher the capacitive value of the input of the phono stage, the duller the sound will be.
That would only be so if it wasn't for the high inductance of the cartridge. Higher capacitance tends to lower the resonant frequency of the cart to a lower point in the treble range. Subjectively that is perceived as increased brightness.

 

awkwardbydesign

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Longer just works better for me
rope+skipping.jpg


 

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