Supex SD-900 MKIV impedance loading

I need to set the impedance loading on a phono stage (Threshold FET10) for a Supex SD-900 MKIV cartridge but do not have the specs. Can anyone help with the manufacturer's recommendation or other guidance? Thanks.
I believe that the internal impedance of the SD-900 Super is 3.5 ohms which may help, or not.
Most LOMC's going into most active phono stages sound best with input impedance at about 25X the internal impedance of the cartridge, + or - 50% depending on the system.

So, if Viridian's figure for your Supex is right, your starting point should be about 87.5 ohms (3.5 x 25).

I believe the nearest input impedance on your FET 10 is 100 ohms, so start there. You'll probably want the 60db gain setting.

Try the other input impedances too and decide for yourself. No setting will damage anything. The one which provides best frequency balance in your system is the one to use. This is one parameter where experimentation is the rule.
Thank you
If you send me your e-mail address I will scan and e-mail you the description out of the 1986 Buyers guide, this way you will have all the information you need.
Hi Dougdeacon
aye, the 25x DCR if you do NOT use an SUT :-)

You may recall our little tête-à-tête, or was it Lewm that begged the wisdom of 2.5x in the case of an SUT involved?

I then had referred him to the Lyra spec. sheets that make a CLEAR differentiation between those two conditions.