How important is the cable between the SUT and phono pre?

Some mm cartridges have a recommended capacitive load for flattest response. This capacitance is the sum of the tone arm wiring, cable to the phono stage and the phono stage input capacitances.

If the capacitive load is below the minimum for a particular mm cartridge it will have a high frequency peak. Moving coil cartridges are immune to capacitive loading.

It has a bypass switch but right now I'm just using various versions of the Denon DL 103 cartridges. So 

MC all the way. I have plenty of good shielded cables so I should have what I need. 

Thanks

BillWojo

Really, really important. Ultra low capacitance, and low run length < 1.0m are key. You need to try to keep it under 50 pF. Don’t use a "normal" thick audiophile interconnect.

Before I knew how important low capacitance was, I did some cable rolling with high quality "normal" interconnects. All the 1m cables had their sonic signature GREATLY magnified, to the point of obvious coloration. The AQ Fire 1m became overly detailed and aggressive. The AQ Sky 1m sounded overly warm, thick and and bloomy. The 0.5m AQ Niagara, normally inferior to the higher-end Fire and Sky, did better and was relatively uncolored - because of the halved length and significantly lower capacitance. The the dedicated AQ WEL LP phono cable (optimized for lower capacitance), 0.5m, blew them all away. The Bob’s Devices 0.7m interconnects are also really good (but the WEL LP is still better) - I have both their copper and silver cables. They’re optimized for SUT use, obviously.

This was all tested on the same Koetsu cartridge and Bob’s Devices Sky SUT.

MC are said to not be sensitive to capacitance, but the problem with a SUT is that it reflects the capacitance of its output cable times the SQUARE of its turns ratio. That’s enough capacitance that it WILL start to affect the MC cartridge.

Many Cardas interconnects have very, very low capacitance - so if you've got those in your collection, give 'em a try. I believe Bob's uses Cardas ingredients to make his cables.

@mulveling

"MC are said to not be sensitive to capacitance, but the problem with a SUT is that it reflects the capacitance of its output cable times the SQUARE of its turns ratio. That’s enough capacitance that it WILL start to affect the MC cartridge."

Can you point me to some more information on this? I was searching for information and found nothing to indicate that this was a problem. I've read that the cables from cartridge to SUT didn't need to be particularly low capacitance but nobody talks about the cables from SUT to phono pre.

Thanks

BillWojo