adventures in qin debug

So I had some adventures the last few months debugging the black real lacquer qin and the red cashew cedar qin. The goal of course was to string them and get them playable. This led to many fine moments of self-doubt and muttered imprecations. There is certainly a stage called "string debug" in qin-making. Let us first go with a stage/stage, blow by blow for each qin:

black-lacquer qin

start with hybrid string on position #6 (wanted 1/6 on first to hold tuner). GAAAA! terrible wierd noises around upper hui position 4-5. I decided something horrible is wrong and panic.

try putting on silk strings just to be totally different. string 6 first -- works ok. hmmm... finish the job.

ok, now we have a different problem. basically bridge buzzes at positions 1-3. Ponder this a long time and eventually come to realize that I should try the hybrid strings again.

back to hybrid strings. use a different string 6 this time. everything works ok... sigh.

lessons:

1. you may have a bad string. that's what happened with string 6. it was a bit unwrapped.
2. the problem with silk strings was that the bridge is too low. More tension on the hybrid strings makes this work. ( I screwed that qin up -- see previous blogs). As a rule of thumb it may be fare to say, a higher bridge may work with silk, but if too low, maybe not.
You shouldn't have rattles at the bridge. Sometimes this can be dealt with by moving the "yingtou" (knot) away from the inner playing edge of the bridge towards the back, but in this case the problem was actually endemic. This was because all the low-tension strings had
the same problem so one couldn't blame it on the knot position on top of the bridge.

There was basically no surface buzzing with this qin perhaps because the action is too high anyway. I also think the superb flow qualities of real lacquer has something to do with this.

red cedar qin

So when I first put strings on we had major buzzes on strings 1-4 around and above hui 10.
There was an occasional buzz from the bridge too. Note that said buzzes did exist when the qin was strung during the "base" (tai) phase. They were new. The bridge buzzes were all dealt with uniformly by making sure the knot was well positioned "inboard" on the bridge (move towards rungkou). There was some stone smoothing needed especially for string 1. However a great deal of the buzziness simply comes from the fact that you have new hybrid strings. They aren't straight (yet). I can't remember that silk strings ever do something like this. I did decide one of the strings was screwed up and replaced it and that got rid of some buzzes as well.

The big lesson is that it might be the strings. Of course buzzes can come from:

1. the bridge
2. the nut
3. the underside where the strings are wrapped or fastened somehow
4. a surface that isn't flat enough
5. a string that has a bump in it
6. a string that is coming unwrapped
7. fundamental flaw in the 3-d geometry of the bridge and top (black lacquer qin qualifies here)
8. something else not in this list