SUT Interconnects

Yeah, sure. If it makes you happy. The first thing I said is that the dielectric can affect capacitance. As to your other point, what temperatures do you have in mind,given that most of us maintain our listening rooms at between 66 and 72 degrees F? And if T is stable, no matter what the value, there would be no change in C due to T for a given IC at a stable T. Your point about the dielectric vs frequency is interesting. Does it apply at audio frequencies? In any case, do you want to agree with west coast and say that “capacitance varies with frequency “? That’s just wrong was my point. At frequencies much higher than audio, all capacitors begin to have problems; they resonate and can become inductive. I took that aberrant behavior as irrelevant to the question. Ceramic caps retain their properties to much higher frequencies than do other types used in audio; that’s why they’re often used to filter RF.

I think that bit of double talk refers to the dielectric effect. Different dielectrics ( insulation) will affect the capacitance of the cable which in turn affects frequency response. Same goes for the spacing between the conductors and the geometry of the cable. All of those factors plus length determine the cable C, which is a constant at all audio frequencies.

No, westcoast, capacitance does not change with frequency.  What you are thinking about is that because of capacitance, impedance changes with frequency.  (Impedance of a capacitor is infinite at DC and goes down as frequency goes up, by an amount dependent upon the value of C.) But that does not matter when you are simply concerned with the capacitance of a cable, or rather impedance is inherent to the question of whether a certain level of capacitance will cause a resonant peak because of interaction with inductance, the other major player in determining the resonant frequency.  Capacitance and inductance are properties of reactance. You only need an accurate and sensitive C meter to measure C. That value does not change with frequency, at least at any audio frequency. (It will change at RF frequencies in the megaherz band.)

What Atmasphere said, but be sure to disconnect the cable at both ends before taking a measurement.  For a balanced cable, the measurement between pins 2 and 3 (positive to negative phase) will be equal to about 0.5X the capacitance between pin 2 and pin 1 (pos phase to ground) and between pin 3 and pin 1 (neg phase to ground), because capacitors in series add like resistors in parallel.

Shielding adds capacitance. Cable geometry also affects capacitance. The 12AX7 tube, often used as the input voltage amplifier in tube MM stages has a high Miller capacitance that adds to cable capacitance. Transistors also add capacitance at the input.

I would have assumed you want low capacitance all the way from the cartridge to the phono inputs. Now you’ve got me thinking.

audioguy85, can you say more about your 1:10 SUT that results in the cartridge seeing 100 ohms? Insofar as transformers have no intrinsic impedance (ideally) you would have to place a 10K resistance across the secondaries of a 1:10 SUT to achieve a 100 ohm load. Maybe that’s what you do. Just curious.

Captive, low capacitance, short length leads are best, sometimes known as "flying leads", because the leads are directly soldered to the transformer secondaries inside the chassis of the SUT, at that one end. That way you at least eliminate an RCA jack and plug in the signal path and effectively minimize capacitance. But if you must traverse a distance of 3 ft or greater from cartridge to phono inputs, it would be preferable to have shortest possible (flying) leads on the cartridge to SUT side and make up the remaining distance on the SUT to phono inputs side.