[CAUT] Pitchlock

[Ron Koval]

>From Greg:

Ron,
         How does one tune a coupled pair of strings? As I understand the
principal they are coupled to sound as one string. How then, are they
separated to be tuned?
>>>>>>>>>>>
It's hard to describe, easier to demonstrate...  The effect is that the 
strings sound together (within a slight distuning)- even if they wouldn't 
measure the same.  It is still possible to hear tuned vs. untuned.  So as 
you move one string away from the other, the beating becomes more apparent, 
as well as quicker.  As you move the strings closer to tune, while the 
beating slows down, (like normal) the loudness of the beating is reduced. 
(not like normal)  I would guess that if the couplers were closer to the 
middle of the string, or more than one coupler was used, two strings could 
be made to move as one.  However, there would be a great change  to the tone 
of those strings.  As it is, the tone of the coupled strings is different 
than the tone of two freely vibrating strings.  The effect is hard to hear 
in practice because there is a third, freely vibrating string added to the 
aural mix.

So the "nuts and bolts" goes something like this:

Tune the rightmost, coupled string a little high.  Tune the second coupled 
string to the first, checking the coupled pitch - using whatever tuning 
preference you have. (The coupled pitch is lower than just one string 
alone.)  I end up using a "split the unison" technique to get these two 
strings exactly in the right place.  That is, working with two open strings 
sounding, and slightly moving one, then the other to nudge the unison into 
place.  Once the right two strings are tuned, bring the left one in tune - 
no problem.

Ron Koval