Helicore Strings
by Rob Krapfl
When Puma was here last fall, I noticed that he had an unusual string he was using for his C(4). I talked to him, and it turned out to be a Helicore (by D'Addario) cello string. He said that he had gotten the whole set of these strings, but that he wasn't able to tune all of his tangents with the new strings, which was a shame because they were the best strings he had ever tried. He let me play his instrument and I was impressed with how nicely that string played.
Since then I have done a lot of experimenting with Helicore strings. I wanted to share the results because I love the sound of these strings. Loose Helicores are much more wiggly, far less rigid, than the Prim strings I am familiar with. They have a very clean and pleasant sound which everyone I ask seems to prefer. I have also noticed that they tune more easily and seem to excite other frequencies less than the Prims. On my instrument, a strongly bowed C(4) from Prim in particular would cause all of the sympathetic strings to start resonating. The Helicore only starts the C strings resonating.
The set that I decided sounds and plays best consists of medium Helicore strings for the C(4), G(3), and C(2), along with a soft Prim A(1) string. The A(1) string from Helicore did not work at all on my instrument (made by Sören Åhker). When it was brought to pitch, it completely damped the entire instrument so that none of the strings sounded good -- the tension was too great. I chose the soft Prim A(1) because it best matched the feel and tone when crossing from the A to C strings. I have not tried any solid A(1) strings with these, as I have always preferred wound strings.
The ability to tune the tangents with these strings is another issue which may or may not be a problem. After installing these strings, I currently have one tangent which can only be tuned to within 10 cents of correct, and there are a couple of others which can only be tuned to within 1 or 2 cents. These are on the G(3) string, and I suspect that others will find some difficulty tuning these tangents as well. Still, I feel these strings are worth it and I have begun carving a new tangent for the note that is 10 cents off. The Helicores have a very soft feel to them -- they may have too soft a feel for some people. I believe they are actually much easier to play and will play louder than the Prims, but they do take some getting used to. One experiment that has not been done yet is to use a set of heavy Helicores with a medium Prim A(1). I did try a heavy G(3), wondering if it made any difference in the position of the tangents. It did not make any difference in tuning, but it did make the string crossings feel strange.
I spoke with a local physicist who happens to build and play Kanteles. He has been studying strings for that instrument and he has been looking at the properties of different materials and how they affect the sound. I told him about my new strings, and asked why a string tuned to a particular frequency and having a fixed length would need to have the tangents at different points. He explained that in theory the tangent positions would be fixed, and it shouldn't matter changing from one string to another. But he also said that near the ends of the string, where it meets the nut and the bridge, it actually behaves more like a rod than a string. How close this transition point is to the nut/bridge will affect the remaining (center) length of string. I found this particularly interesting in relation to the G(3) string because many nyckelharpor, including mine, have a little notch cut out of the nut to slightly lengthen that string. Since the Helicores are substantially more flexible than the Prim or Jörpland strings, his explanation would predict that the Helicore would need to be slightly shorter. It makes me think...
I also experimented with viola strings. D'Addario makes a set of Helicore strings for a 400mm vibration length, and at the correct pitches for a nyckelharpa! These strings worked well, but the character of the nyckelharpa was lost. It sounded much more like a viola, sounded too refined. I think the nyckelharpa needs some edge to its sound. They were also very thin and looked a little out of place, since we are used to the fat strings and sound out of the nyckelharpa.
John Farrow has tried Helicore strings and really likes them. He said that the Helicore A(1) works on his instrument (made by Harry Hedbom) although it must be played lightly. Bart Brashers has also tried the Helicores-plus-Prim-A(1) set. He likes the way the C(4) and G(3) sound and feel, but found the C(2) a little weak for his instrument (made by Åke Ahlstrand) and personal style. He really couldn't stand the soft Prim A(1), and decided that it was worth having a bit of mismatch in tone to get the character from the A(1) string he wants, and went with a medium Prim A(1) string. He has ordered a Helicore heavy gauge C(2), but as of this writing it hasn't arrived yet. It should be kept in mind that every instrument is different, and what works well on one instrument may not work well on another. The Helicores cost a bit more than Prims, about $14, $29 and $35 for the C(2), G(3) and C(4) respectively, as opposed to about $12, $14 and $16 for the Prims. That makes it a $36 experiment to try the Helicores, which may not be so bad, in the scheme of things.
Helicore strings by D'Addario are available from standard music stores that serve classical instruments, as well as on-line at JustStrings.com, swstrings.com, and others. If you try these strings, or any others, please share your experience with the rest of us so we can all gain from individual successes and don't have to repeat individual failures!