I am very happy with my new Eudoxa-Olive viola C-string. I am both a violist and a violin/viola maker. The viola I play on I made in 2016. Its body length is 16 5/8” with a string length of 368mm. I modeled it on a 17 1/2” Gaspar da Salo instrument. The current setup requires a very low tension G-string, for which I use Eudoxa Stiff. The C-string tension needs to be higher than the Eudoxa Stiff C, however. The Evah Pirazzi Gold C works fine, but mixing gut and synthetic core strings gave me intonation problems. The Eudoxa-Olive C has a similar tension to the Evah Gold C, and I am very happy that it works on my instrument. It responds differently than the Evah Gold C, and I had to get used to the difference. At first I thought the response was slower, but now that it is played in, I think that is not the case. Also, the string diameter is thicker than the Evah Gold C, so it feels different under my fingers. The sound is darker, but not as dark as the Oliv C, which made my viola sound like a cello. The response is very good, and I can play closer to the bridge and with more volume now than I ever could on this instrument, as well as very softly yet still distictly clear over the fingerboard.
A note about string tension: You can find the tension numbers on Pirastro’s web page. Some instruments are more sensitive to having just the right string tension and combinations of string tensions among the four strings. I have found that a string that has too much tension for the instrument will not speak properly; my bow feels like it has butter on the hair instead of rosin. On the other hand, if the string has too little tension, it feels like a rubber band when I play on it and won’t let me “dig in” at all. Also, an A-string with too much tension may play fine, but cause the C-string to be dull and unresponsive.