SUT Interconnects


What cables have you tried between an MC SUT box and 47K MM phono stage? What was your favorite?

I’ve tried the AudioQuest upper-line "normal" ineterconnect cables (Sky, Fire) - great cables in other slots - but very colored coming out of a SUT. Not great performance. I assume that at 1.0m+ lengths, their capactitance is far too high for this application. I’ve tried 0.5m runs of Wind & Niagara (a bit lower in their "normal" IC line, slightly smaller guage wire and less shielding to boot) and got better results. However, my best results by far are with a 0.5m AQ WEL Signature LP phono cable (optimized for low capacitance phono applications). I’ve also tried the Bob’s Devices custom cables, 0.7m, both copper and solid silver versions - these have good performance (particularly the silver), but are more on the level of the 0.5m Niagara, still short of the WEL LP.

The problem I have is that the WEL LP is quite spendy, and I want a 2nd good SUT cable for a 2nd arm & SUT setup. Looking for more reasonably priced options. I’ve had excellent results with a Synergistic Research Foundation phono cable on a tonearm (DIN plug), and wonder how a short all-RCA run of it might do off a SUT (also interested in the Atmosphere X series). Any experience with SR or other cables off a SUT would be appreciated!

mulveling

You've already tried Bob's cables, so I can't add much value here but that's what I'm using. When I purchased Bob's SUT I got his cables because it's what I demoed and I mentally just considered it part of the system. 

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.)

Lewm, here is some cable manufacturer material to read about cables. There is also amplifier circuit input capacitance, which could be quite hard to measure. http://www.mogami.com/e/notes/capacitance.html

"For cable using material having good high-frequency characteristics in non-polar molecule, such as polyethylene, these vales are not varies with freauency and temperature. But for the cable using PVC compound and other polar molecule material, capacitance is largely depends on frequency and temperature."

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.

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.

Not correct.

  • The dielectric constant can change with temperature, and this change can be significant, especially for certain materials. For example, some ceramic materials used as dielectrics in capacitors can have a temperature coefficient, meaning their capacitance changes with temperature. 

  • Frequency Dependence:

    At higher frequencies, the dielectric constant may not be able to "keep up" with the rapidly changing electric field, leading to a frequency-dependent behavior. This means that the effective capacitance can vary with frequency.