20pf/foot is a practical value for a cable. Mogami makes a console cable that specs in this area. Since transformers can receive either a single-ended signal or balanced, you could run a balanced connection from your arm to the SUT and thus obviate the sonic attributes (or artifacts, however you want to look at it) of the cable.
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!
Showing 3 responses by atmasphere
The inductance of the cartridge and transformer in parallel with the capacitance of the tonearm cable causes an electrical resonance. Best to keep that resonance as high as possible. Depending on the transformer design you may well have to load the transformer in a certain way to deal with this resonance. So its best to minimize variables by minimizing the capacitive aspects since there is little you can do about the inductances involved. This is one reason why I prefer to run direct if I can. |
@mulveling Its critical to keep the capacitance down on either side of the transformer. Ultimately you'll want to load the transformer correctly for the cartridge you have and the input impedance of the phono section (typically 47KOhms). Some SUTs are designed for a specific cartridge and assume a 47KOhm load so these are less worries. Something like a Jensen which is designed to work with a wide variety of cartridges will need very specific loading to work right. The interconnects are part of that loading and very simply have to be low capacitance. |