bass string problem

[Michael Spalding]

David,

Aluminum, not nickel.   Aluminum wound strings behave differently than copper wound, because the aluminum is less dense than copper.  I'm told they did it because, on paper at least, it allowed better blending of tension, inharmonicity, and loudness/power at the break.  In reality, how smooth does that break sound to you??  Anyway, because the aluminum is way less dense than copper, a copper wound string of the same diameter would be heavier, thus require higher tension to reach the same pitch.  That's why your same-size copper universal broke.  To find a copper universal that would pull up to the same tension as the original, you'd have to run the numbers, but it would be about half to 2/3 the diameter of the aluminum original.   I'm guessing you'd hear the difference and you wouldn't like it.  Ordering a (aluminum wound) replacement was the right solution.

  Mike


----- Original Message ----- 
From: David Nereson 
To: List Pianotech
Sent: 9/22/2006 10:07:56 PM 
Subject: bass string problem


            Had a string break in the low tenor during a pitch raise on a 1983 Everett console.  Decided to put on a universal string and leave it if it sounded OK.  (Would order custom string if it didn’t).  Measured the string on the tapered slot gauge and it said # 8, so that’s what I put on.  Wouldn’t pull up to pitch – it broke.  Have only had that happen maybe twice in 25 years.  Brand new strings can usually be pulled way over pitch and still not break.  So tried a # 8 ½  instead, thinking it’s meant to be at a higher pitch than the # 8.  Nope, it broke too!  
            Now, the winding on the original string is aluminum or nickel (I assume), not copper, but should that matter?  It’s the core wire that holds the tension, right?  I measured them all when I got home and the original string’s core wire is .037”, the # 8 measured .039”, and the # 8 ½ measured .038”, I believe.  Shouldn’t that be close enough?  Should I go back and try a # 9?   
            I’m going to send in the original and have a custom string made, but I’m wondering why the universals broke way before they were up to pitch.  No, I didn’t see any burrs, etc. on the upper plate bearing, pressure bar, etc. 
            --David Nereson, RPT
 
P.S.  Why did they use aluminum or nickel wound for the two lowest tenor strings, when all the bass are copper?
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