Loading the Koetsu Urushi


Hello All -

Those of you who have used the Urushi, what did you find the best loading to be? I am going into a CAT Ultimate preamp. Thanks very much, Peter S.
peter_s
The loading will only be critical if your phono section is sensitive to Radio Frequency Interference (RFI)!

IOW, loading values that small don't affect the cartridge at audio frequencies. You hear a difference because the phono section gets upset if RFI is present.

The inductance of the cartridge and the capacitance of the interconnect cable form a tuned RF circuit that becomes excited (resonates) when energy is supplied by the cartridge tracking in the groove. The resistor detunes the circuit if the value is correct, eliminating the excitation voltage (which is often quite high- in the MHz range).

So- if your preamp is unaffected by RFI you will hear little or no change with the loading.
Hi; I would agree with the above post. I have found that with my CAT Ultimate or CAT Legend 100 Ohm loading would appear optimum for my Koetsu Urushi black moving coil cartridge.
For the first three years of this cartridge I had been loading it at 100 Ohms but recently I have switched to the 249 Ohm setting on my Krell KPE Reference phono pre. I felt that after it was fully broken in that the highs had become just ever so slightly attentuated. The new setting restores these. I realize I may be getting close to a retip/rebuild. Perhaps the suspension has finally sagged/settled just a little and so I have also backed the VTF down from 2.0 grams to 1.9 grams and this too has restored some of the air without any mistracking. Basically I would recommend that you begin as close to 100 Ohms (as Koetsu and other Agoners suggest)as your phono stage allows you to get and then work around this as a starting point. Keep in mind there is no one correct loading setting and some of this depends on your cabling to the phono pre as well. My table is a VPI Aries 2 with a JMW 10.5 arm with stock cable. I use Harmonic Technologies Silver phono cable. Other Urushi owners will chime in here too but I predict many will concur that 100 Ohm is the preferred loading.