You have an excellent cart.
i say: Loading is like a tone control and is set by user (ear) preference.
Lyra says: Recommended load directly into MC phono input : 91ohms - 47kohm (determine by listening, or follow detailed guidelines)???
JonathanValin commented: http://www.theabsolutesound.com/answers/94/
(In this question and comments, although the cart is all together different, the theory is very useful and the sources are very credible)
Mark….BTW I’m both a Delos and PS0.3R user and for years have applied a load setting of 220.
EBM therefore gets the cigar for his inspired guess. ;^)
FYI the input capacitance of the 0.3R is by, coincidence, 220pF (as told to me by James Henriot) so you should add your cable capacitance to this figure before deciding what your initial loading might be.
Note that your room acoustic and the degree of toe-in of the speakers (depending on what type you use) will influence the result which is why you should experiment rather than take the standard advice that “no one should run a Lyra with anything less than 470”.
As has been rightly highlighted by R_F_Sayles, Jonathan Carr is one of the most regular and helpful manufacturing contributors on the Forum. If you do a search for Delos & J.Carr on Audiogon you will be rewarded with a wealth of information.